diff --git a/404.html b/404.html
index ac86897..ce5eeca 100644
--- a/404.html
+++ b/404.html
@@ -240,7 +240,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html" class="external-link">4. Using the full power of the Docker CLI</a>
+        <a href="https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html" class="external-link">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -382,8 +382,8 @@ <h1>Page not found</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/404.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/404.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/CODE_OF_CONDUCT.html b/CODE_OF_CONDUCT.html
index 2fe3474..1d88f32 100644
--- a/CODE_OF_CONDUCT.html
+++ b/CODE_OF_CONDUCT.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -323,7 +323,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Contributor Code of Conduct</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/CODE_OF_CONDUCT.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -402,8 +402,8 @@ <h1>Contributor Code of Conduct</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/CODE_OF_CONDUCT.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/CODE_OF_CONDUCT.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/LICENSE.html b/LICENSE.html
index 1506d00..2069fd3 100644
--- a/LICENSE.html
+++ b/LICENSE.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -323,7 +323,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Licenses</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/LICENSE.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -450,8 +450,8 @@ <h1>Licenses</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/LICENSE.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/LICENSE.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/aio.html b/aio.html
index bc8b71c..965e0b2 100644
--- a/aio.html
+++ b/aio.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -378,7 +378,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         
 <section id="aio-introduction"><p>Content from <a href="introduction.html">Introducing Containers</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/introduction.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -670,7 +670,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-desktop"><p>Content from <a href="docker-desktop.html">Docker Desktop</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-desktop.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -835,22 +835,22 @@ <h3 class="tab-header" id="nav-tab-heading-1-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-1" class="tab-content">
-<div id="nav-tabpanel-1-Logs" class="tab-pane show active" aria-labelledby="nav-tab-1-Logs" role="tabpanel">
+<div id="nav-tabpanel-1-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-1-Logs">
 <figure><img src="fig/docker-desktop/hello_log.png" alt="Logs tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Inspect" class="tab-pane" aria-labelledby="nav-tab-1-Inspect" role="tabpanel">
+<div id="nav-tabpanel-1-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Inspect">
 <figure><img src="fig/docker-desktop/hello_inspect.png" alt="Inspect tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-1-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Bindmounts">
 <figure><img src="fig/docker-desktop/hello_bind.png" alt="Bind mounts tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Exec" class="tab-pane" aria-labelledby="nav-tab-1-Exec" role="tabpanel">
+<div id="nav-tabpanel-1-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Exec">
 <figure><img src="fig/docker-desktop/hello_exec.png" alt="Exec tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Files" class="tab-pane" aria-labelledby="nav-tab-1-Files" role="tabpanel">
+<div id="nav-tabpanel-1-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Files">
 <figure><img src="fig/docker-desktop/hello_files.png" alt="Files tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Stats" class="tab-pane" aria-labelledby="nav-tab-1-Stats" role="tabpanel">
+<div id="nav-tabpanel-1-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Stats">
 <figure><img src="fig/docker-desktop/hello_stats.png" alt="Stats tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -932,22 +932,22 @@ <h3 class="tab-header" id="nav-tab-heading-2-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-2" class="tab-content">
-<div id="nav-tabpanel-2-Logs" class="tab-pane show active" aria-labelledby="nav-tab-2-Logs" role="tabpanel">
+<div id="nav-tabpanel-2-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-2-Logs">
 <figure><img src="fig/docker-desktop/spuc_log.png" alt="Logs tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Inspect" class="tab-pane" aria-labelledby="nav-tab-2-Inspect" role="tabpanel">
+<div id="nav-tabpanel-2-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Inspect">
 <figure><img src="fig/docker-desktop/spuc_inspect.png" alt="Inspect tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-2-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Bindmounts">
 <figure><img src="fig/docker-desktop/spuc_bind.png" alt="Bind mounts tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Exec" class="tab-pane" aria-labelledby="nav-tab-2-Exec" role="tabpanel">
+<div id="nav-tabpanel-2-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Exec">
 <figure><img src="fig/docker-desktop/spuc_exec.png" alt="Exec tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Files" class="tab-pane" aria-labelledby="nav-tab-2-Files" role="tabpanel">
+<div id="nav-tabpanel-2-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Files">
 <figure><img src="fig/docker-desktop/spuc_files.png" alt="Files tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Stats" class="tab-pane" aria-labelledby="nav-tab-2-Stats" role="tabpanel">
+<div id="nav-tabpanel-2-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Stats">
 <figure><img src="fig/docker-desktop/spuc_stats.png" alt="Stats tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -1127,22 +1127,22 @@ <h3 class="tab-header" id="nav-tab-heading-3-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-3" class="tab-content">
-<div id="nav-tabpanel-3-Logs" class="tab-pane show active" aria-labelledby="nav-tab-3-Logs" role="tabpanel">
+<div id="nav-tabpanel-3-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-3-Logs">
 <figure><img src="fig/docker-desktop/alpine_logs.png" alt="Logs tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Inspect" class="tab-pane" aria-labelledby="nav-tab-3-Inspect" role="tabpanel">
+<div id="nav-tabpanel-3-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Inspect">
 <figure><img src="fig/docker-desktop/alpine_inspect.png" alt="Inspect tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-3-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Bindmounts">
 <figure><img src="fig/docker-desktop/alpine_bind.png" alt="Bind mounts tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Exec" class="tab-pane" aria-labelledby="nav-tab-3-Exec" role="tabpanel">
+<div id="nav-tabpanel-3-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Exec">
 <figure><img src="fig/docker-desktop/alpine_exec.png" alt="Exec tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Files" class="tab-pane" aria-labelledby="nav-tab-3-Files" role="tabpanel">
+<div id="nav-tabpanel-3-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Files">
 <figure><img src="fig/docker-desktop/alpine_files.png" alt="Files tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Stats" class="tab-pane" aria-labelledby="nav-tab-3-Stats" role="tabpanel">
+<div id="nav-tabpanel-3-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Stats">
 <figure><img src="fig/docker-desktop/alpine_stats.png" alt="Stats tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -1188,7 +1188,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-cli-toolkit"><p>Content from <a href="docker-cli-toolkit.html">Building our Docker CLI toolkit</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-toolkit.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -1736,7 +1736,7 @@ <h3 class="accordion-header" id="headingSpoiler1">
   Logs
   </h3>
 </button>
-<div id="collapseSpoiler1" class="accordion-collapse collapse" data-bs-parent="#accordionSpoiler1" aria-labelledby="headingSpoiler1">
+<div id="collapseSpoiler1" class="accordion-collapse collapse" aria-labelledby="headingSpoiler1" data-bs-parent="#accordionSpoiler1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2193,9 +2193,9 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </div>
 </div>
-</section></section><section id="aio-docker-cli-advanced"><p>Content from <a href="docker-cli-advanced.html">Using the full power of the Docker CLI</a></p>
+</section></section><section id="aio-docker-cli-advanced"><p>Content from <a href="docker-cli-advanced.html">Sharing information with containers</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-advanced.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -2212,9 +2212,7 @@ <h2 class="card-header">Overview</h2>
 <div class="inner">
 <h3 class="card-title">Questions</h3>
 <ul>
-<li>What actually happens when I run a container?</li>
-<li>How can I control the behaviour of containers?</li>
-<li>How do I get data in and out of containers?</li>
+<li>How do I get information in and out of containers?</li>
 </ul>
 </div>
 </div>
@@ -2224,85 +2222,78 @@ <h3 class="card-title">Questions</h3>
 <div class="inner bordered">
 <h3 class="card-title">Objectives</h3>
 <ul>
-<li>Learn the lifecycle of Docker containers</li>
-<li>Learn about Entrypoints and Commands and how to manipulate them</li>
 <li>Learn how to use files with container using mounts and volumes</li>
+<li>Learn how to set environment variables and pass parameters to
+containers</li>
 </ul>
 </div>
 </div>
 </div>
 </div>
 </div>
-<div class="section level1">
-<h1 id="data-in-containers">Data in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a>
-</h1>
-<p>In the earlier section on Docker Desktop, we learned how to interact
-with containers and used this to have a look at the
-unicorn_sightings.txt file.</p>
-<p>It is quite annoying that the file does not persist between runs of
-the container! Also, with the file being in the container, we can’t
-(easily) do much with it.</p>
-<p>This is where the Docker CLI starts to shine.</p>
-<div class="section level2">
-<h2 id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a>
+<section><h2 class="section-heading" id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a>
 </h2>
+<hr class="half-width">
+<p>In the earlier sections we interacted with the SPUC container and
+made changes to the <code>print.config</code> file. We also registered
+some unicorn sightings using the API, which were recorded in the
+<code>unicorn_sightings.txt</code> file. However, we lost all those
+changes when we stopped the container.</p>
 <p>Docker containers are naturally isolated from the host system,
-meaning that they have their own filesystems and cannot access the host
-filesystem.</p>
-<p>They are also ephemeral, meaning that they are designed to be
-temporary and are destroyed when they are stopped.</p>
+meaning that they have their own filesystem, and cannot access the host
+filesystem. They are also designed to be temporary, and are destroyed
+when they are stopped.</p>
 <p>This is mostly a good thing, as it means that containers are
 lightweight and can be easily recreated, but we can’t be throwing our
 unicorn sightings away like this!</p>
-<p>Luckily, Docker has methods for allowing containers to persist
+<p>Also, with the file being in the container, we can’t (easily) do much
+with it. Luckily, Docker has methods for allowing containers to persist
 data.</p>
-<div class="section level3">
-<h3 id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a>
-</h3>
-<p>The first way to allow a container to access the host filesystem is
-by using a <code>volume</code>. A volume is a specially designated
-directory on the host filesystem which is shared with the container,
-hidden away deep in the host filesystem.</p>
-<p>Volumes are very tightly controlled by Docker, and are designed to be
-used for sharing data between containers, or for persisting data between
-runs of a container. They are very useful, but can be a bit tricky to
-use.</p>
+</section><section><h2 class="section-heading" id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a>
+</h2>
+<hr class="half-width">
+<p>One way to allow a container to access the host filesystem is by
+using a <code>volume</code>. A volume is a specially designated
+directory hidden away deep in the host filesystem. This directory is
+shared with the container.</p>
+<p>Volumes are very tightly controlled by Docker. They are designed to
+be used for sharing data between containers, or for persisting data
+between runs of a container.</p>
 <p>Let’s have a look at how we can use a volume to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+We do this by modifying our <code>run</code> command to include a
+<code>-v</code> (for volume) flag, a volume name and a path inside the
 container.</p>
-<p>We do this by modifying our <code>docker run</code> command to
-include a <code>-v</code> (for volume) flag, a volume name and a path
-inside the container.</p>
-<p><strong>Note</strong>: You have to be <em>really</em> careful with
-the syntax for this command. See the challenge box below for common
-mistakes (and their resolution).</p>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code><span><span class="va">f1bd2bb9062348b6a1815f5076fcd1b79e603020c2d58436408c6c60da7e73d2</span></span></code></pre>
 </div>
-<p>Ok! But what is happening?</p>
-<p>We can see what containers we have created using:</p>
+<p>Ok! But what is happening? We can see what containers we have created
+using:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> docker volume ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">docker</span> volume ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>local     spuc-volume</code></pre>
 </div>
-<p>And we can see information about the volume using:</p>
+<div class="section level3 spolier">
+<h3 id="inspecting-the-volume">Inspecting the volume<a class="anchor" aria-label="anchor" href="#inspecting-the-volume"></a>
+</h3>
+<p>We can see more information about the volume using:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> docker volume inspect spuc-volume</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">docker</span> volume inspect spuc-volume</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2321,18 +2312,18 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Which shows us that the volume is stored in
 <code>/var/lib/docker/volumes/spuc-volume/_data</code> on the host
-filesystem. Which you can visit if you have superuser permissions
-(sudo).</p>
-<p>But what about the container? Has this actually worked? Let’s record
-some sightings and see if they persist between runs.</p>
-<p>First, what’s that over there?? A unicorn! No… three unicorns! Let’s
+filesystem. You can visit and edit files there if you have superuser
+permissions (sudo).</p>
+</div>
+<p>But what about the container? Has this actually worked?</p>
+<p>First… what’s that over there?? A unicorn! No… three unicorns! Let’s
 record these sightings.</p>
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2345,142 +2336,142 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuhc</code></pre>
+<pre class="output" tabindex="0"><code>count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
-<p>Now for our test, we will stop the container, run it again and check
-the sightings file.</p>
+<p>Now, for our test, we will stop the container. Since we used the
+<code>-rm</code> flag, the container will also be deleted.</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">docker</span> ps <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuh</code></pre>
-</div>
-<p>So there we have it! The sightings persist between runs of the
-container. This is a great way to keep data between runs of a container,
-but watch out for the syntax!</p>
-<div id="common-mistakes-with-volumes" class="callout discussion">
-<div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<pre class="output" tabindex="0"><code>spuc_container
+CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES</code></pre>
 </div>
-<div id="common-mistakes-with-volumes" class="callout-inner">
-<h3 class="callout-title">Common mistakes with volumes</h3>
-<div class="callout-content">
-<p>Given you are in a directory containing a directory named
-<code>spuc</code>, what will happen when you run the following
-commands?</p>
-<ol style="list-style-type: upper-alpha">
-<li><p>$ docker run -v ./spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ./spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spucs:/foo spuc:latest</p></li>
-</ol>
+<p>This would have been game over, but we used a volume. Let’s run it
+again and check the sightings file.</p>
+<div class="codewrapper sourceCode" id="cb13">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span>
+<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>536a6d2f73061aa94729df3536ee86b60dcd68f4652bfbdc9e4cfa9c6cfda168
+count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
+<p>It’s worked! The unicorn sightings are still there! The only problem
+is that the file is still in the container, and we can’t easily access
+it from the host filesystem.</p>
+</section><section><h2 class="section-heading" id="bind-mounts">Bind mounts<a class="anchor" aria-label="anchor" href="#bind-mounts"></a>
+</h2>
+<hr class="half-width">
+<p>Another way to allow a container to access the host filesystem is by
+using a <code>bind mount</code>. A bind mount is a direct mapping of a
+specified directory on the host filesystem to a directory in the
+container filesystem. This allows you to directly access files on the
+host filesystem from the container, but it has its own challenges.</p>
+<p>Let’s have a look at how we can use a bind mount to persist the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+Confusingly, bind mounting is also done using the <code>-v</code> flag.
+However, instead of a name for the volume, we have to specify a path on
+the host filesystem.</p>
+<p><strong>Note:</strong> In older versions of Docker the path had to be
+<em>absolute</em>; <em>relative</em> paths are now supported.</p>
+<div class="codewrapper sourceCode" id="cb15">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
-<div class="accordion-item">
-<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
-  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
-</button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
-<div class="accordion-body">
-<ol style="list-style-type: upper-alpha">
-<li>The path to the volume must be an absolute path, not a relative
-path. You can use the $PWD environment variable to get the current
-working directory. This will create a (root owned) directory in the
-current working directory, which is not what you want. Use “sudo rm -rf
-./spuc-volume” to remove the volume and try again.</li>
-<li>This is the correct syntax for creating a volume. This will create a
-volume called spuc-volume and mount it to the /foo directory in the
-container.</li>
-<li>Because ./spuc is not an absolute path, this will create a new
-volume called spuc and mount it to the /foo directory in the container.
-This is not what you want. Use “sudo rm -rf ./spuc” to remove the volume
-and try again.</li>
-<li>This is valid syntax but not for creating a volume! This will create
-a bind mount instead. More on these next.</li>
-<li>This will create a new volume called spuc<strong>s</strong> and
-mount it to the /foo directory in the container. This is not what you
-want. Use “sudo rm -rf ./spucs” to remove the volume and try again.</li>
-</ol>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>spuc_container
+79620ff93fdd8135dcc7f595223144c075a9df53fc32f2ce799ee8e338b9df41</code></pre>
 </div>
+<p>The directory <code>spuc/output</code> likely did not exist in your
+current working directory, so Docker created one. It is currently empty,
+as you can see by listing the contents with <code>ls spuc/output</code>.
+If we now record a unicorn sighting, we can see the records file in the
+directory.</p>
+<div class="codewrapper sourceCode" id="cb17">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{message:"Unicorn sighting recorded!"}
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
+<p>and the file is still there even after stopping the container</p>
+<div class="codewrapper sourceCode" id="cb19">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="fu">ls</span> spuc/output</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code><span><span class="va">spuc_container</span></span>
+<span><span class="va">unicorn_sightings.txt</span></span></code></pre>
 </div>
-<div class="section level3">
-<h3 id="bind-mounting-directories">Bind mounting directories<a class="anchor" aria-label="anchor" href="#bind-mounting-directories"></a>
-</h3>
-<p>The second way to allow a container to access the host filesystem is
-by using a <code>bind mount</code>. A bind mount is a direct mapping of
-a directory on the host filesystem to a directory in the container
-filesystem.</p>
-<p>This can be appealing, as it allows you to directly access files on
-the host filesystem from the container, but it has its own
-challenges.</p>
-<p>Let’s have a look at how we can use a bind mount to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
-container.</p>
-<p>Confusingly, bind mounting is also done using the <code>-v</code>
-flag, but with a different syntax. We specify an
-<strong>absolute</strong> path to the directory on the host filesystem,
-followed by a colon, followed by the path to the directory in the
-container filesystem.</p>
-<p>It can be annoying to type the full path to a directory, so we can
-use the <code>$PWD</code> environment variable to get the current
-working directory.</p>
-<div class="codewrapper sourceCode" id="cb13">
+<p>If we run the container again, we can see the file is still
+there.</p>
+<div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container </span>
-<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/spuc:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb13-3"><a href="#cb13-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
-<span id="cb13-4"><a href="#cb13-4" tabindex="-1"></a><span class="ex">$</span> tree spuc/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span>
+<span id="cb21-2"><a href="#cb21-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>spuc/
-└── unicorn_sightings.txt</code></pre>
+<pre class="output" tabindex="0"><code>3dd079c21845fc36ddc3b20fd525790a1e194c198c4b98337f4ed82bfc7a9755
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
-<p>So now we can access the /code/output directory in the container on
-the host filesystem. This is totally functional way to persist data
-between runs of a container but there are downsides.</p>
-<p>To illusrate this, let’s see what the permissions are on the file we
+<p>So we not only managed to persist the data between runs of the
+container, but we can also access the file when the container is not
+running. This is great!… but there are downsides.</p>
+<p>To illustrate this, let’s see what the permissions are on the file we
 just created.</p>
-<div class="codewrapper sourceCode" id="cb15">
+<div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="fu">ls</span> <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>-rw-r--r-- 1 root root 57 Oct 11 14:14 spuc/unicorn_sightings.txt</code></pre>
 </div>
-<p>Argh, the file is owned by root!</p>
-<p>This is because the container runs as root, and so any files created
-by the container are owned by root. This can be a problem, as you will
-not have permission to access the file without using
-<code>sudo</code>.</p>
+<p>Argh, the file is owned by root! This is because the container runs
+as root, and so any files created by the container are owned by root.
+This can be a problem, as you will not have permission to access the
+file without using <code>sudo</code>.</p>
 <p>This is a common problem with bind mounts, and can be a bit of a pain
 to deal with. You can change the ownership of the file using
 <code>sudo chown</code>, but this can be a bit of a hassle.</p>
@@ -2488,79 +2479,144 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 are not managed by Docker. The management of bind mounts is left to the
 user.</p>
 <p>Really, neither volumes nor bind mounts are perfect, but they are
-both useful tools for persisting data between runs of a container and
-have both allowed us to keep the unicorn_sightings.txt file between runs
-of the container.</p>
-<p>Later in these lessons we will see some more ergonomic ways to work
-with volumes and bind mounts.</p>
-</div>
-</div>
-<div class="section level2">
-<h2 id="sharing-files-with-containers">Sharing files with containers<a class="anchor" aria-label="anchor" href="#sharing-files-with-containers"></a>
-</h2>
-<p>Earlier, we looked at how to change the config file in SPUC to enable
-exporting. This was a bit of a hassle, as we had to use the Docker
-Desktop interface to do this and it did not persist between runs of the
+both useful tools for persisting data between runs of a container.</p>
+<div class="section level3">
+<h3 id="bind-mount-files">Bind mount files<a class="anchor" aria-label="anchor" href="#bind-mount-files"></a>
+</h3>
+<p>Earlier, we looked at how to change the print.config file in SPUC to
+format the logs. This was a bit difficult, as we had to do it from
+inside the container, and it did not persist between runs of the
 container.</p>
 <p>We now have the tools to address this! We can use a bind mount to
 share the config file with the container.</p>
-<p>Let’s have a look at how we can do this. First we need to make the
-config file itself.</p>
-<p>The SPUC README on dockerhub tells us that the config file should be
-in the following format:</p>
-<pre class="plaintext"><code>::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}</code></pre>
-<p>And should be present at <code>/code/config/print.config</code>.</p>
-<p>Let’s get to it then. First we need to make the file (on the
-host).</p>
-<div class="codewrapper sourceCode" id="cb18">
+<p>First we need to make the config file itself. Let’s create a file
+with the following content:</p>
+<div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> echo <span class="st">"::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: {time} Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
-<p>Now we can bind mount this file to the container. Again we will use
-<code>-v</code> and the <code>$PWD</code> environment variable to get
-the current working directory. This time, however, we will specify a
-specific file to mount, not a directory.</p>
-<div class="codewrapper sourceCode" id="cb19">
+<p>Now, to share it with the container, we need to put it in the path
+<code>/spuc/config/print.config</code>. Again we will use
+<code>-v</code>, but we will specify the path to the file, instead of a
+directory.</p>
+<div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<p>Now if we check the logs of the container, we can see that the config
-file has been loaded correctly and that the print format has been
-changed.</p>
-<p>First, let’s record another sighting, then check the logs.</p>
-<div class="codewrapper sourceCode" id="cb20">
+<p>Now let’s check if this worked. For that, we need to record another
+sighting and then check the logs.</p>
+<div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=jupyter\&amp;brightness=100</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>[...]
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
 [...]
-::::: (2024-10-11 14:29:07.548965) Unicorn spotted at moon!! Brightness: 100 iuhc</code></pre>
+::::: 2024-10-16 10:53:13.449393 Unicorn number 4 spotted at jupyter! Brightness: 100 iuhc</code></pre>
 </div>
-<p>Fantastic! We have now managed to share a file with the container,
-and have changed the behaviour of the container using this file.</p>
-<div class="section level3">
-<h3 id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a>
+<p>Fantastic! We have now managed to share a file with the container.
+Not only that, but because we created the file before mounting it to the
+container, we are the owners, and can modify it. Changes to the file
+will reflect immediately on the container.</p>
+<p>For example, let’s edit the file to get rid of the date:</p>
+<div class="codewrapper sourceCode" id="cb29">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<p>We have learned about volumes and bind mounts, two ways to allow a
-container to access the host filesystem. We have used these to persist
-data between runs of a container and to share files with a
-container.</p>
-<p>They can both be a bit tricky to use, but are very useful tools for
-working with containers and have helped us get SPUC working much more
-like we want it to.</p>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+</div>
+<p>Now let’s register a sighting, and look at the logs:</p>
+<div class="codewrapper sourceCode" id="cb30">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=venus\&amp;brightness=148</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
+</div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
+[...]
+::::: Unicorn number 7 spotted at venus! Brightness: 148 iuhc</code></pre>
+</div>
+<p>It almost seems too easy! We now have a print configuration and
+unicorn sighting record that persists between runs of the container.</p>
+<p><strong>Warning</strong>: We <em>replaced</em> the file in the
+container with the file from the host filesystem. We could do the same
+with a whole directory, but be careful not to overwrite important files
+in the container!</p>
+<div id="common-mistakes-with-volumes" class="callout challenge">
+<div class="callout-square">
+<i class="callout-icon" data-feather="zap"></i>
+</div>
+<div id="common-mistakes-with-volumes" class="callout-inner">
+<h3 class="callout-title">Common mistakes with volumes</h3>
+<div class="callout-content">
+<p>You have to be <em>really</em> careful with the syntax for volumes
+and mounts.</p>
+<p>Let’s imagine you are in a path containing a directory
+<code>spuc</code>, with an empty sub-directory <code>output</code> and a
+<code>print.config</code> file. What do you think will happen when you
+run the following commands?</p>
+<ol style="list-style-type: upper-alpha">
+<li><code>docker run -v spuc-vol spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spucs/output:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc-vol:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc:/spuc spuacv/spuc:latest</code></li>
+<li><code>docker run -v print.config:/spuc/config/print.config spuacv/spuc:latest</code></li>
+</ol>
 </div>
 </div>
-<div class="section level2">
-<h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a>
+</div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div class="accordion-body">
+<ol style="list-style-type: upper-alpha">
+<li><p><strong>Problem:</strong> We provided a volume name, but not a
+path to mount it to. If the volume already existed, this will mount it
+on <code>/spuc-vol</code>. If the volume did not exist, it will create a
+directory <code>/spuc-vol</code> in the container, but it wont
+persist!<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Stop it and try again.</p></li>
+<li><p><strong>Problem:</strong> You misspelled the path! This will
+create a new directory called spuc<strong>s</strong> and mount it.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spucs</code> to remove the
+directory and try again.</p></li>
+<li><p><strong>Problem:</strong> At first, it seems like we will create
+a volume. However, we have provided a path, not a name for the volume.
+Therefore, Docker thinks you want a bind mount, and will create a (root
+owned) directory called <code>spuc-vol</code>.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spuc-volume</code> to
+remove the directory and try again.</p></li>
+<li><p><strong>Problem:</strong> This is valid syntax for a bind mount.
+It will take the almost empty <code>spuc</code> directory in your
+filesystem and mount it to <code>/spuc</code> in the container. However,
+it replaced everything in there in the process! Your command most likely
+failed because it could not find <code>/spuc/spuc.py</code>.<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Try again.</p></li>
+<li><p><strong>Problem:</strong> We forgot to use a path for the file!
+This will try to create a new volume called <code>print.config</code>
+and mount it to <code>/spuc/config/print.config</code>. However, it will
+most likely fail because <code>print.config</code> is not a
+directory.<br><strong>Fix:</strong> Use <code>docker volume rm print.config</code> to
+remove the volume and try again.</p></li>
+</ol>
+</div>
+</div>
+</div>
+</div>
+</div>
+</section><section><h2 class="section-heading" id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a>
 </h2>
+<hr class="half-width">
 <p>One other interesting reading from the SPUC README is the presence of
 an environment variable, <code>EXPORT</code> which can be set to
 <code>True</code> to enable an API endpoint for exporting the unicorn
@@ -2570,12 +2626,12 @@ <h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-l
 <p>Thankfully this is quite straightforward, we can use the
 <code>-e</code> flag to set an environment variable in a container.</p>
 <p>Modifying our run command again:</p>
-<div class="codewrapper sourceCode" id="cb22">
+<div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb32-2"><a href="#cb32-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest</span>
+<span id="cb32-3"><a href="#cb32-3" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2589,10 +2645,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ::::: Or 'curl localhost:8321/export' to download the unicorn sightings file!</code></pre>
 </div>
 <p>And now we can see that the export endpoint is available!</p>
-<div class="codewrapper sourceCode" id="cb24">
+<div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2609,10 +2665,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Environment variables are a very common tool for configuring
 containers. They are used to set things like API keys, database
 connection strings, and other configuration options.</p>
-</div>
-<div class="section level2">
-<h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a>
+</section><section><h2 class="section-heading" id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a>
 </h2>
+<hr class="half-width">
 <p>Finally, we must address a very serious shortcoming of the SPUC
 container. It is recording the brightness of the unicorns in Imperial
 Unicorn Hoove Candles (iuhc)! This is a very outdated unit and we
@@ -2621,13 +2676,13 @@ <h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anch
 the container to set the units to metric. This is done by passing a
 parameter to the container when it is run, overriding the default
 command.</p>
-<div class="codewrapper sourceCode" id="cb26">
+<div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest <span class="at">--units</span> iulu</span>
-<span id="cb26-3"><a href="#cb26-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb26-4"><a href="#cb26-4" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest <span class="at">--units</span> iulu</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export/</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2650,21 +2705,21 @@ <h3 class="callout-title">Callout</h3>
 different command in the container, or if you want to run the container
 interactively.</p>
 <p>You may recall:</p>
-<div class="codewrapper sourceCode" id="cb28">
+<div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">docker</span> inspect ghcr.io/uomresearchit/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
-<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /code/spuc.py] Command: [--units iuhc]</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">docker</span> inspect spuacv/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
+<span id="cb38-2"><a href="#cb38-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /spuc/spuc.py] Command: [--units iuhc]</span></code></pre>
 </div>
-<p>That SPUC has an entrypoint of <code>python /code/spuc.py</code>
+<p>That SPUC has an entrypoint of <code>python /spuc/spuc.py</code>
 making it hard to interact with. We can override this using the
 <code>--entrypoint</code> flag.</p>
-<div class="codewrapper sourceCode" id="cb29">
+<div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="discussion2" class="callout discussion">
+<div id="discussion1" class="callout discussion">
 <div class="callout-square">
 <i class="callout-icon" data-feather="message-circle"></i>
 </div>
@@ -2682,23 +2737,23 @@ <h3 class="callout-title">Challenge</h3>
 <tbody>
 <tr class="odd">
 <td>A</td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 <td></td>
 </tr>
 <tr class="even">
 <td>B</td>
-<td><code>python /code/spuc.py</code></td>
+<td><code>python /spuc/spuc.py</code></td>
 <td><code>--units iuhc</code></td>
 </tr>
 <tr class="odd">
 <td>C</td>
 <td><code>python</code></td>
-<td><code>/code/spuc.py --units iuhc</code></td>
+<td><code>/spuc/spuc.py --units iuhc</code></td>
 </tr>
 <tr class="even">
 <td>D</td>
 <td></td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 </tr>
 </tbody>
 </table>
@@ -2710,7 +2765,7 @@ <h3 class="callout-title">Challenge</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>These are all valid combinations! The best choice depends on the use
 case.</p>
@@ -2733,10 +2788,9 @@ <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </div>
 </div>
 </div>
-</div>
-<div class="section level2">
-<h2 id="summary-1">Summary<a class="anchor" aria-label="anchor" href="#summary-1"></a>
+</section><section><h2 class="section-heading" id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a>
 </h2>
+<hr class="half-width">
 <p>In this section, we have learned about volumes and bind mounts, two
 ways to allow a container to access the host filesystem. We have used
 these to persist data between runs of a container and to share files
@@ -2762,10 +2816,9 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </div>
 </div>
-</div>
-</div></section><section id="aio-docker-hub"><p>Content from <a href="docker-hub.html">The Docker Hub</a></p>
+</section></section><section id="aio-docker-hub"><p>Content from <a href="docker-hub.html">The Docker Hub</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-hub.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -3022,7 +3075,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-creating-container-images"><p>Content from <a href="creating-container-images.html">Creating Your Own Container Images</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/creating-container-images.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -3490,7 +3543,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-compose"><p>Content from <a href="docker-compose.html">Using Docker Compose</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-compose.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -4401,8 +4454,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/aio.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/aio.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/creating-container-images.html b/creating-container-images.html
index b226481..3c4c57d 100644
--- a/creating-container-images.html
+++ b/creating-container-images.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -339,7 +339,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Creating Your Own Container Images</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/creating-container-images.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -849,8 +849,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/creating-container-images.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/creating-container-images.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/docker-cli-advanced.html b/docker-cli-advanced.html
index af790fb..4d4b889 100644
--- a/docker-cli-advanced.html
+++ b/docker-cli-advanced.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<!-- START: inst/pkgdown/templates/layout.html --><!-- Generated by pkgdown: do not edit by hand --><html lang="en" data-bs-theme="auto"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><title>Introduction to Docker: Using the full power of the Docker CLI</title><meta name="viewport" content="width=device-width, initial-scale=1"><script src="assets/themetoggle.js"></script><link rel="stylesheet" type="text/css" href="assets/styles.css"><script src="assets/scripts.js" type="text/javascript"></script><!-- mathjax --><script type="text/x-mathjax-config">
+<!-- START: inst/pkgdown/templates/layout.html --><!-- Generated by pkgdown: do not edit by hand --><html lang="en" data-bs-theme="auto"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><title>Introduction to Docker: Sharing information with containers</title><meta name="viewport" content="width=device-width, initial-scale=1"><script src="assets/themetoggle.js"></script><link rel="stylesheet" type="text/css" href="assets/styles.css"><script src="assets/scripts.js" type="text/javascript"></script><!-- mathjax --><script type="text/x-mathjax-config">
     MathJax.Hub.Config({
       config: ["MMLorHTML.js"],
       jax: ["input/TeX","input/MathML","output/HTML-CSS","output/NativeMML", "output/PreviewHTML"],
@@ -232,13 +232,25 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlushcurrent">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-headingcurrent">
+      <button class="accordion-button" type="button" data-bs-toggle="collapse" data-bs-target="#flush-collapsecurrent" aria-expanded="true" aria-controls="flush-collapsecurrent">
         <span class="visually-hidden">Current Chapter</span>
         <span class="current-chapter">
-        4. Using the full power of the Docker CLI
+        4. Sharing information with containers
         </span>
-      
+      </button>
     </div><!--/div.accordion-header-->
 
+    <div id="flush-collapsecurrent" class="accordion-collapse collapse show" aria-labelledby="flush-headingcurrent" data-bs-parent="#accordionFlushcurrent">
+      <div class="accordion-body">
+        <ul><li><a href="#making-our-data-persist">Making our data persist</a></li>
+<li><a href="#volumes">Volumes</a></li>
+<li><a href="#bind-mounts">Bind mounts</a></li>
+<li><a href="#setting-the-environment">Setting the environment</a></li>
+<li><a href="#passing-parameters">Passing parameters</a></li>
+<li><a href="#summary">Summary</a></li>
+        </ul></div><!--/div.accordion-body-->
+    </div><!--/div.accordion-collapse-->
+
   </div><!--/div.accordion-item-->
 </div><!--/div.accordion-flush-->
 
@@ -326,8 +338,8 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         </a>
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
-        <h1>Using the full power of the Docker CLI</h1>
-        <p>Last updated on 2024-10-15 |
+        <h1>Sharing information with containers</h1>
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-advanced.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -349,9 +361,7 @@ <h2 class="card-header">Overview</h2>
 <div class="card-body">
 <div class="inner">
 <h3 class="card-title">Questions</h3>
-<ul><li>What actually happens when I run a container?</li>
-<li>How can I control the behaviour of containers?</li>
-<li>How do I get data in and out of containers?</li>
+<ul><li>How do I get information in and out of containers?</li>
 </ul></div>
 </div>
 </div>
@@ -359,81 +369,72 @@ <h3 class="card-title">Questions</h3>
 <div class="card-body">
 <div class="inner bordered">
 <h3 class="card-title">Objectives</h3>
-<ul><li>Learn the lifecycle of Docker containers</li>
-<li>Learn about Entrypoints and Commands and how to manipulate them</li>
-<li>Learn how to use files with container using mounts and volumes</li>
+<ul><li>Learn how to use files with container using mounts and volumes</li>
+<li>Learn how to set environment variables and pass parameters to
+containers</li>
 </ul></div>
 </div>
 </div>
 </div>
 </div>
-<div class="section level1">
-<h1 id="data-in-containers">Data in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></h1>
-<p>In the earlier section on Docker Desktop, we learned how to interact
-with containers and used this to have a look at the
-unicorn_sightings.txt file.</p>
-<p>It is quite annoying that the file does not persist between runs of
-the container! Also, with the file being in the container, we can’t
-(easily) do much with it.</p>
-<p>This is where the Docker CLI starts to shine.</p>
-<div class="section level2">
-<h2 id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a></h2>
+<section><h2 class="section-heading" id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a></h2>
+<hr class="half-width"><p>In the earlier sections we interacted with the SPUC container and
+made changes to the <code>print.config</code> file. We also registered
+some unicorn sightings using the API, which were recorded in the
+<code>unicorn_sightings.txt</code> file. However, we lost all those
+changes when we stopped the container.</p>
 <p>Docker containers are naturally isolated from the host system,
-meaning that they have their own filesystems and cannot access the host
-filesystem.</p>
-<p>They are also ephemeral, meaning that they are designed to be
-temporary and are destroyed when they are stopped.</p>
+meaning that they have their own filesystem, and cannot access the host
+filesystem. They are also designed to be temporary, and are destroyed
+when they are stopped.</p>
 <p>This is mostly a good thing, as it means that containers are
 lightweight and can be easily recreated, but we can’t be throwing our
 unicorn sightings away like this!</p>
-<p>Luckily, Docker has methods for allowing containers to persist
+<p>Also, with the file being in the container, we can’t (easily) do much
+with it. Luckily, Docker has methods for allowing containers to persist
 data.</p>
-<div class="section level3">
-<h3 id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a></h3>
-<p>The first way to allow a container to access the host filesystem is
-by using a <code>volume</code>. A volume is a specially designated
-directory on the host filesystem which is shared with the container,
-hidden away deep in the host filesystem.</p>
-<p>Volumes are very tightly controlled by Docker, and are designed to be
-used for sharing data between containers, or for persisting data between
-runs of a container. They are very useful, but can be a bit tricky to
-use.</p>
+</section><section><h2 class="section-heading" id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a></h2>
+<hr class="half-width"><p>One way to allow a container to access the host filesystem is by
+using a <code>volume</code>. A volume is a specially designated
+directory hidden away deep in the host filesystem. This directory is
+shared with the container.</p>
+<p>Volumes are very tightly controlled by Docker. They are designed to
+be used for sharing data between containers, or for persisting data
+between runs of a container.</p>
 <p>Let’s have a look at how we can use a volume to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+We do this by modifying our <code>run</code> command to include a
+<code>-v</code> (for volume) flag, a volume name and a path inside the
 container.</p>
-<p>We do this by modifying our <code>docker run</code> command to
-include a <code>-v</code> (for volume) flag, a volume name and a path
-inside the container.</p>
-<p><strong>Note</strong>: You have to be <em>really</em> careful with
-the syntax for this command. See the challenge box below for common
-mistakes (and their resolution).</p>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code><span><span class="va">f1bd2bb9062348b6a1815f5076fcd1b79e603020c2d58436408c6c60da7e73d2</span></span></code></pre>
 </div>
-<p>Ok! But what is happening?</p>
-<p>We can see what containers we have created using:</p>
+<p>Ok! But what is happening? We can see what containers we have created
+using:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> docker volume ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">docker</span> volume ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>local     spuc-volume</code></pre>
 </div>
-<p>And we can see information about the volume using:</p>
+<div class="section level3 spolier">
+<h3 id="inspecting-the-volume">Inspecting the volume<a class="anchor" aria-label="anchor" href="#inspecting-the-volume"></a></h3>
+<p>We can see more information about the volume using:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> docker volume inspect spuc-volume</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">docker</span> volume inspect spuc-volume</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -452,18 +453,18 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Which shows us that the volume is stored in
 <code>/var/lib/docker/volumes/spuc-volume/_data</code> on the host
-filesystem. Which you can visit if you have superuser permissions
-(sudo).</p>
-<p>But what about the container? Has this actually worked? Let’s record
-some sightings and see if they persist between runs.</p>
-<p>First, what’s that over there?? A unicorn! No… three unicorns! Let’s
+filesystem. You can visit and edit files there if you have superuser
+permissions (sudo).</p>
+</div>
+<p>But what about the container? Has this actually worked?</p>
+<p>First… what’s that over there?? A unicorn! No… three unicorns! Let’s
 record these sightings.</p>
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -476,137 +477,140 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuhc</code></pre>
+<pre class="output" tabindex="0"><code>count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
-<p>Now for our test, we will stop the container, run it again and check
-the sightings file.</p>
+<p>Now, for our test, we will stop the container. Since we used the
+<code>-rm</code> flag, the container will also be deleted.</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">docker</span> ps <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuh</code></pre>
-</div>
-<p>So there we have it! The sightings persist between runs of the
-container. This is a great way to keep data between runs of a container,
-but watch out for the syntax!</p>
-<div id="common-mistakes-with-volumes" class="callout discussion">
-<div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<pre class="output" tabindex="0"><code>spuc_container
+CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES</code></pre>
 </div>
-<div id="common-mistakes-with-volumes" class="callout-inner">
-<h3 class="callout-title">Common mistakes with volumes</h3>
-<div class="callout-content">
-<p>Given you are in a directory containing a directory named
-<code>spuc</code>, what will happen when you run the following
-commands?</p>
-<ol style="list-style-type: upper-alpha"><li><p>$ docker run -v ./spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ./spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spucs:/foo spuc:latest</p></li>
-</ol></div>
+<p>This would have been game over, but we used a volume. Let’s run it
+again and check the sightings file.</p>
+<div class="codewrapper sourceCode" id="cb13">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span>
+<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>536a6d2f73061aa94729df3536ee86b60dcd68f4652bfbdc9e4cfa9c6cfda168
+count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
+</div>
+<p>It’s worked! The unicorn sightings are still there! The only problem
+is that the file is still in the container, and we can’t easily access
+it from the host filesystem.</p>
+</section><section><h2 class="section-heading" id="bind-mounts">Bind mounts<a class="anchor" aria-label="anchor" href="#bind-mounts"></a></h2>
+<hr class="half-width"><p>Another way to allow a container to access the host filesystem is by
+using a <code>bind mount</code>. A bind mount is a direct mapping of a
+specified directory on the host filesystem to a directory in the
+container filesystem. This allows you to directly access files on the
+host filesystem from the container, but it has its own challenges.</p>
+<p>Let’s have a look at how we can use a bind mount to persist the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+Confusingly, bind mounting is also done using the <code>-v</code> flag.
+However, instead of a name for the volume, we have to specify a path on
+the host filesystem.</p>
+<p><strong>Note:</strong> In older versions of Docker the path had to be
+<em>absolute</em>; <em>relative</em> paths are now supported.</p>
+<div class="codewrapper sourceCode" id="cb15">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
-<div class="accordion-item">
-<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
-  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
-</button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
-<div class="accordion-body">
-<ol style="list-style-type: upper-alpha"><li>The path to the volume must be an absolute path, not a relative
-path. You can use the $PWD environment variable to get the current
-working directory. This will create a (root owned) directory in the
-current working directory, which is not what you want. Use “sudo rm -rf
-./spuc-volume” to remove the volume and try again.</li>
-<li>This is the correct syntax for creating a volume. This will create a
-volume called spuc-volume and mount it to the /foo directory in the
-container.</li>
-<li>Because ./spuc is not an absolute path, this will create a new
-volume called spuc and mount it to the /foo directory in the container.
-This is not what you want. Use “sudo rm -rf ./spuc” to remove the volume
-and try again.</li>
-<li>This is valid syntax but not for creating a volume! This will create
-a bind mount instead. More on these next.</li>
-<li>This will create a new volume called spuc<strong>s</strong> and
-mount it to the /foo directory in the container. This is not what you
-want. Use “sudo rm -rf ./spucs” to remove the volume and try again.</li>
-</ol></div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>spuc_container
+79620ff93fdd8135dcc7f595223144c075a9df53fc32f2ce799ee8e338b9df41</code></pre>
+</div>
+<p>The directory <code>spuc/output</code> likely did not exist in your
+current working directory, so Docker created one. It is currently empty,
+as you can see by listing the contents with <code>ls spuc/output</code>.
+If we now record a unicorn sighting, we can see the records file in the
+directory.</p>
+<div class="codewrapper sourceCode" id="cb17">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{message:"Unicorn sighting recorded!"}
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
+<p>and the file is still there even after stopping the container</p>
+<div class="codewrapper sourceCode" id="cb19">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="fu">ls</span> spuc/output</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code><span><span class="va">spuc_container</span></span>
+<span><span class="va">unicorn_sightings.txt</span></span></code></pre>
 </div>
-<div class="section level3">
-<h3 id="bind-mounting-directories">Bind mounting directories<a class="anchor" aria-label="anchor" href="#bind-mounting-directories"></a></h3>
-<p>The second way to allow a container to access the host filesystem is
-by using a <code>bind mount</code>. A bind mount is a direct mapping of
-a directory on the host filesystem to a directory in the container
-filesystem.</p>
-<p>This can be appealing, as it allows you to directly access files on
-the host filesystem from the container, but it has its own
-challenges.</p>
-<p>Let’s have a look at how we can use a bind mount to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
-container.</p>
-<p>Confusingly, bind mounting is also done using the <code>-v</code>
-flag, but with a different syntax. We specify an
-<strong>absolute</strong> path to the directory on the host filesystem,
-followed by a colon, followed by the path to the directory in the
-container filesystem.</p>
-<p>It can be annoying to type the full path to a directory, so we can
-use the <code>$PWD</code> environment variable to get the current
-working directory.</p>
-<div class="codewrapper sourceCode" id="cb13">
+<p>If we run the container again, we can see the file is still
+there.</p>
+<div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container </span>
-<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/spuc:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb13-3"><a href="#cb13-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
-<span id="cb13-4"><a href="#cb13-4" tabindex="-1"></a><span class="ex">$</span> tree spuc/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span>
+<span id="cb21-2"><a href="#cb21-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>spuc/
-└── unicorn_sightings.txt</code></pre>
-</div>
-<p>So now we can access the /code/output directory in the container on
-the host filesystem. This is totally functional way to persist data
-between runs of a container but there are downsides.</p>
-<p>To illusrate this, let’s see what the permissions are on the file we
+<pre class="output" tabindex="0"><code>3dd079c21845fc36ddc3b20fd525790a1e194c198c4b98337f4ed82bfc7a9755
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
+</div>
+<p>So we not only managed to persist the data between runs of the
+container, but we can also access the file when the container is not
+running. This is great!… but there are downsides.</p>
+<p>To illustrate this, let’s see what the permissions are on the file we
 just created.</p>
-<div class="codewrapper sourceCode" id="cb15">
+<div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="fu">ls</span> <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>-rw-r--r-- 1 root root 57 Oct 11 14:14 spuc/unicorn_sightings.txt</code></pre>
 </div>
-<p>Argh, the file is owned by root!</p>
-<p>This is because the container runs as root, and so any files created
-by the container are owned by root. This can be a problem, as you will
-not have permission to access the file without using
-<code>sudo</code>.</p>
+<p>Argh, the file is owned by root! This is because the container runs
+as root, and so any files created by the container are owned by root.
+This can be a problem, as you will not have permission to access the
+file without using <code>sudo</code>.</p>
 <p>This is a common problem with bind mounts, and can be a bit of a pain
 to deal with. You can change the ownership of the file using
 <code>sudo chown</code>, but this can be a bit of a hassle.</p>
@@ -614,77 +618,138 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 are not managed by Docker. The management of bind mounts is left to the
 user.</p>
 <p>Really, neither volumes nor bind mounts are perfect, but they are
-both useful tools for persisting data between runs of a container and
-have both allowed us to keep the unicorn_sightings.txt file between runs
-of the container.</p>
-<p>Later in these lessons we will see some more ergonomic ways to work
-with volumes and bind mounts.</p>
-</div>
-</div>
-<div class="section level2">
-<h2 id="sharing-files-with-containers">Sharing files with containers<a class="anchor" aria-label="anchor" href="#sharing-files-with-containers"></a></h2>
-<p>Earlier, we looked at how to change the config file in SPUC to enable
-exporting. This was a bit of a hassle, as we had to use the Docker
-Desktop interface to do this and it did not persist between runs of the
+both useful tools for persisting data between runs of a container.</p>
+<div class="section level3">
+<h3 id="bind-mount-files">Bind mount files<a class="anchor" aria-label="anchor" href="#bind-mount-files"></a></h3>
+<p>Earlier, we looked at how to change the print.config file in SPUC to
+format the logs. This was a bit difficult, as we had to do it from
+inside the container, and it did not persist between runs of the
 container.</p>
 <p>We now have the tools to address this! We can use a bind mount to
 share the config file with the container.</p>
-<p>Let’s have a look at how we can do this. First we need to make the
-config file itself.</p>
-<p>The SPUC README on dockerhub tells us that the config file should be
-in the following format:</p>
-<pre class="plaintext"><code>::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}</code></pre>
-<p>And should be present at <code>/code/config/print.config</code>.</p>
-<p>Let’s get to it then. First we need to make the file (on the
-host).</p>
-<div class="codewrapper sourceCode" id="cb18">
+<p>First we need to make the config file itself. Let’s create a file
+with the following content:</p>
+<div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> echo <span class="st">"::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: {time} Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
-<p>Now we can bind mount this file to the container. Again we will use
-<code>-v</code> and the <code>$PWD</code> environment variable to get
-the current working directory. This time, however, we will specify a
-specific file to mount, not a directory.</p>
-<div class="codewrapper sourceCode" id="cb19">
+<p>Now, to share it with the container, we need to put it in the path
+<code>/spuc/config/print.config</code>. Again we will use
+<code>-v</code>, but we will specify the path to the file, instead of a
+directory.</p>
+<div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<p>Now if we check the logs of the container, we can see that the config
-file has been loaded correctly and that the print format has been
-changed.</p>
-<p>First, let’s record another sighting, then check the logs.</p>
-<div class="codewrapper sourceCode" id="cb20">
+<p>Now let’s check if this worked. For that, we need to record another
+sighting and then check the logs.</p>
+<div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=jupyter\&amp;brightness=100</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>[...]
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
 [...]
-::::: (2024-10-11 14:29:07.548965) Unicorn spotted at moon!! Brightness: 100 iuhc</code></pre>
+::::: 2024-10-16 10:53:13.449393 Unicorn number 4 spotted at jupyter! Brightness: 100 iuhc</code></pre>
 </div>
-<p>Fantastic! We have now managed to share a file with the container,
-and have changed the behaviour of the container using this file.</p>
-<div class="section level3">
-<h3 id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a></h3>
-<p>We have learned about volumes and bind mounts, two ways to allow a
-container to access the host filesystem. We have used these to persist
-data between runs of a container and to share files with a
-container.</p>
-<p>They can both be a bit tricky to use, but are very useful tools for
-working with containers and have helped us get SPUC working much more
-like we want it to.</p>
+<p>Fantastic! We have now managed to share a file with the container.
+Not only that, but because we created the file before mounting it to the
+container, we are the owners, and can modify it. Changes to the file
+will reflect immediately on the container.</p>
+<p>For example, let’s edit the file to get rid of the date:</p>
+<div class="codewrapper sourceCode" id="cb29">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
+<p>Now let’s register a sighting, and look at the logs:</p>
+<div class="codewrapper sourceCode" id="cb30">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=venus\&amp;brightness=148</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
-<div class="section level2">
-<h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a></h2>
-<p>One other interesting reading from the SPUC README is the presence of
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
+[...]
+::::: Unicorn number 7 spotted at venus! Brightness: 148 iuhc</code></pre>
+</div>
+<p>It almost seems too easy! We now have a print configuration and
+unicorn sighting record that persists between runs of the container.</p>
+<p><strong>Warning</strong>: We <em>replaced</em> the file in the
+container with the file from the host filesystem. We could do the same
+with a whole directory, but be careful not to overwrite important files
+in the container!</p>
+<div id="common-mistakes-with-volumes" class="callout challenge">
+<div class="callout-square">
+<i class="callout-icon" data-feather="zap"></i>
+</div>
+<div id="common-mistakes-with-volumes" class="callout-inner">
+<h3 class="callout-title">Common mistakes with volumes</h3>
+<div class="callout-content">
+<p>You have to be <em>really</em> careful with the syntax for volumes
+and mounts.</p>
+<p>Let’s imagine you are in a path containing a directory
+<code>spuc</code>, with an empty sub-directory <code>output</code> and a
+<code>print.config</code> file. What do you think will happen when you
+run the following commands?</p>
+<ol style="list-style-type: upper-alpha"><li><code>docker run -v spuc-vol spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spucs/output:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc-vol:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc:/spuc spuacv/spuc:latest</code></li>
+<li><code>docker run -v print.config:/spuc/config/print.config spuacv/spuc:latest</code></li>
+</ol></div>
+</div>
+</div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div class="accordion-body">
+<ol style="list-style-type: upper-alpha"><li><p><strong>Problem:</strong> We provided a volume name, but not a
+path to mount it to. If the volume already existed, this will mount it
+on <code>/spuc-vol</code>. If the volume did not exist, it will create a
+directory <code>/spuc-vol</code> in the container, but it wont
+persist!<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Stop it and try again.</p></li>
+<li><p><strong>Problem:</strong> You misspelled the path! This will
+create a new directory called spuc<strong>s</strong> and mount it.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spucs</code> to remove the
+directory and try again.</p></li>
+<li><p><strong>Problem:</strong> At first, it seems like we will create
+a volume. However, we have provided a path, not a name for the volume.
+Therefore, Docker thinks you want a bind mount, and will create a (root
+owned) directory called <code>spuc-vol</code>.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spuc-volume</code> to
+remove the directory and try again.</p></li>
+<li><p><strong>Problem:</strong> This is valid syntax for a bind mount.
+It will take the almost empty <code>spuc</code> directory in your
+filesystem and mount it to <code>/spuc</code> in the container. However,
+it replaced everything in there in the process! Your command most likely
+failed because it could not find <code>/spuc/spuc.py</code>.<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Try again.</p></li>
+<li><p><strong>Problem:</strong> We forgot to use a path for the file!
+This will try to create a new volume called <code>print.config</code>
+and mount it to <code>/spuc/config/print.config</code>. However, it will
+most likely fail because <code>print.config</code> is not a
+directory.<br><strong>Fix:</strong> Use <code>docker volume rm print.config</code> to
+remove the volume and try again.</p></li>
+</ol></div>
+</div>
+</div>
+</div>
+</div>
+</section><section><h2 class="section-heading" id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a></h2>
+<hr class="half-width"><p>One other interesting reading from the SPUC README is the presence of
 an environment variable, <code>EXPORT</code> which can be set to
 <code>True</code> to enable an API endpoint for exporting the unicorn
 sightings.</p>
@@ -693,12 +758,12 @@ <h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-l
 <p>Thankfully this is quite straightforward, we can use the
 <code>-e</code> flag to set an environment variable in a container.</p>
 <p>Modifying our run command again:</p>
-<div class="codewrapper sourceCode" id="cb22">
+<div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb32-2"><a href="#cb32-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest</span>
+<span id="cb32-3"><a href="#cb32-3" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -712,10 +777,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ::::: Or 'curl localhost:8321/export' to download the unicorn sightings file!</code></pre>
 </div>
 <p>And now we can see that the export endpoint is available!</p>
-<div class="codewrapper sourceCode" id="cb24">
+<div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -732,10 +797,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Environment variables are a very common tool for configuring
 containers. They are used to set things like API keys, database
 connection strings, and other configuration options.</p>
-</div>
-<div class="section level2">
-<h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a></h2>
-<p>Finally, we must address a very serious shortcoming of the SPUC
+</section><section><h2 class="section-heading" id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a></h2>
+<hr class="half-width"><p>Finally, we must address a very serious shortcoming of the SPUC
 container. It is recording the brightness of the unicorns in Imperial
 Unicorn Hoove Candles (iuhc)! This is a very outdated unit and we
 <strong>must</strong> change it to metric.</p>
@@ -743,13 +806,13 @@ <h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anch
 the container to set the units to metric. This is done by passing a
 parameter to the container when it is run, overriding the default
 command.</p>
-<div class="codewrapper sourceCode" id="cb26">
+<div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest <span class="at">--units</span> iulu</span>
-<span id="cb26-3"><a href="#cb26-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb26-4"><a href="#cb26-4" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest <span class="at">--units</span> iulu</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export/</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -772,21 +835,21 @@ <h3 class="callout-title">Callout</h3>
 different command in the container, or if you want to run the container
 interactively.</p>
 <p>You may recall:</p>
-<div class="codewrapper sourceCode" id="cb28">
+<div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">docker</span> inspect ghcr.io/uomresearchit/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
-<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /code/spuc.py] Command: [--units iuhc]</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">docker</span> inspect spuacv/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
+<span id="cb38-2"><a href="#cb38-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /spuc/spuc.py] Command: [--units iuhc]</span></code></pre>
 </div>
-<p>That SPUC has an entrypoint of <code>python /code/spuc.py</code>
+<p>That SPUC has an entrypoint of <code>python /spuc/spuc.py</code>
 making it hard to interact with. We can override this using the
 <code>--entrypoint</code> flag.</p>
-<div class="codewrapper sourceCode" id="cb29">
+<div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="discussion2" class="callout discussion">
+<div id="discussion1" class="callout discussion">
 <div class="callout-square">
 <i class="callout-icon" data-feather="message-circle"></i>
 </div>
@@ -799,17 +862,17 @@ <h3 class="callout-title">Challenge</h3>
 <th>Entrypoint</th>
 <th>Command</th>
 </tr></thead><tbody><tr class="odd"><td>A</td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 <td></td>
 </tr><tr class="even"><td>B</td>
-<td><code>python /code/spuc.py</code></td>
+<td><code>python /spuc/spuc.py</code></td>
 <td><code>--units iuhc</code></td>
 </tr><tr class="odd"><td>C</td>
 <td><code>python</code></td>
-<td><code>/code/spuc.py --units iuhc</code></td>
+<td><code>/spuc/spuc.py --units iuhc</code></td>
 </tr><tr class="even"><td>D</td>
 <td></td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 </tr></tbody></table></div>
 </div>
 </div>
@@ -818,7 +881,7 @@ <h3 class="callout-title">Challenge</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>These are all valid combinations! The best choice depends on the use
 case.</p>
@@ -839,10 +902,8 @@ <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </div>
 </div>
 </div>
-</div>
-<div class="section level2">
-<h2 id="summary-1">Summary<a class="anchor" aria-label="anchor" href="#summary-1"></a></h2>
-<p>In this section, we have learned about volumes and bind mounts, two
+</section><section><h2 class="section-heading" id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a></h2>
+<hr class="half-width"><p>In this section, we have learned about volumes and bind mounts, two
 ways to allow a container to access the host filesystem. We have used
 these to persist data between runs of a container and to share files
 with a container.</p>
@@ -865,12 +926,7 @@ <h3 class="callout-title">Key Points</h3>
 </ul></div>
 </div>
 </div>
-</div>
-</div>
-
-
-
-      </div> <!-- / div.lesson-content -->
+</section></div> <!-- / div.lesson-content -->
     </main><!-- / main#main-content.main-content --><nav class="bottom-pagination mx-md-4" aria-label="Previous and Next Chapter"><div class="d-block d-sm-block d-md-none">
         <a class="chapter-link" href="docker-cli-toolkit.html"><i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>Previous</a>
         <a class="chapter-link float-end" href="docker-hub.html">Next<i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i></a>
@@ -923,13 +979,13 @@ <h3 class="callout-title">Key Points</h3>
   "dct:conformsTo": "https://bioschemas.org/profiles/TrainingMaterial/1.0-RELEASE",
   "description": "A Carpentries Lesson teaching foundational data and coding skills to researchers worldwide",
   "keywords": "software, data, lesson, The Carpentries",
-  "name": "Using the full power of the Docker CLI",
+  "name": "Sharing information with containers",
   "creativeWorkStatus": "active",
   "url": "https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/docker-cli-toolkit.html b/docker-cli-toolkit.html
index b1e4fdb..0bc81a1 100644
--- a/docker-cli-toolkit.html
+++ b/docker-cli-toolkit.html
@@ -253,7 +253,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -338,13 +338,13 @@ <h2 class="accordion-header" id="flush-headingTwelve">
           Previous: Docker Desktop
         </a>
         <a class="chapter-link float-end" href="docker-cli-advanced.html" rel="next">
-          Next: Using the full power...
+          Next: Sharing information...
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i>
         </a>
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Building our Docker CLI toolkit</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-toolkit.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -871,7 +871,7 @@ <h3 class="accordion-header" id="headingSpoiler1">
   Logs
   </h3>
 </button>
-<div id="collapseSpoiler1" class="accordion-collapse collapse" data-bs-parent="#accordionSpoiler1" aria-labelledby="headingSpoiler1">
+<div id="collapseSpoiler1" class="accordion-collapse collapse" aria-labelledby="headingSpoiler1" data-bs-parent="#accordionSpoiler1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1262,7 +1262,7 @@ <h3 class="callout-title">Key Points</h3>
           Previous: Docker Desktop
         </a>
         <a class="chapter-link float-end" href="docker-cli-advanced.html" rel="next">
-          Next: Using the full power...
+          Next: Sharing information...
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i>
         </a>
       </div>
@@ -1308,8 +1308,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/docker-cli-toolkit.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/docker-cli-toolkit.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/docker-compose.html b/docker-compose.html
index 75440d4..d76b101 100644
--- a/docker-compose.html
+++ b/docker-compose.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -341,7 +341,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Using Docker Compose</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-compose.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -1189,8 +1189,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/docker-compose.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/docker-compose.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/docker-desktop.html b/docker-desktop.html
index 9fb7c2a..af5a905 100644
--- a/docker-desktop.html
+++ b/docker-desktop.html
@@ -250,7 +250,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -341,7 +341,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Docker Desktop</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-desktop.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -502,17 +502,17 @@ <h3 class="tab-header" id="nav-tab-heading-1-Stats">
 </button>
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+<div id="nav-tabpanel-1-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-1-Logs">
 <figure><img src="fig/docker-desktop/hello_log.png" alt="Logs tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Inspect" class="tab-pane" aria-labelledby="nav-tab-1-Inspect" role="tabpanel">
+<div id="nav-tabpanel-1-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Inspect">
 <figure><img src="fig/docker-desktop/hello_inspect.png" alt="Inspect tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-1-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Bindmounts">
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-<div id="nav-tabpanel-1-Exec" class="tab-pane" aria-labelledby="nav-tab-1-Exec" role="tabpanel">
+<div id="nav-tabpanel-1-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Exec">
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-<div id="nav-tabpanel-1-Files" class="tab-pane" aria-labelledby="nav-tab-1-Files" role="tabpanel">
+<div id="nav-tabpanel-1-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Files">
 <figure><img src="fig/docker-desktop/hello_files.png" alt="Files tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Stats" class="tab-pane" aria-labelledby="nav-tab-1-Stats" role="tabpanel">
+<div id="nav-tabpanel-1-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Stats">
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-<div id="nav-tabpanel-2-Logs" class="tab-pane show active" aria-labelledby="nav-tab-2-Logs" role="tabpanel">
+<div id="nav-tabpanel-2-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-2-Logs">
 <figure><img src="fig/docker-desktop/spuc_log.png" alt="Logs tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Inspect" class="tab-pane" aria-labelledby="nav-tab-2-Inspect" role="tabpanel">
+<div id="nav-tabpanel-2-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Inspect">
 <figure><img src="fig/docker-desktop/spuc_inspect.png" alt="Inspect tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-2-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Bindmounts">
 <figure><img src="fig/docker-desktop/spuc_bind.png" alt="Bind mounts tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Exec" class="tab-pane" aria-labelledby="nav-tab-2-Exec" role="tabpanel">
+<div id="nav-tabpanel-2-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Exec">
 <figure><img src="fig/docker-desktop/spuc_exec.png" alt="Exec tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Files" class="tab-pane" aria-labelledby="nav-tab-2-Files" role="tabpanel">
+<div id="nav-tabpanel-2-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Files">
 <figure><img src="fig/docker-desktop/spuc_files.png" alt="Files tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Stats" class="tab-pane" aria-labelledby="nav-tab-2-Stats" role="tabpanel">
+<div id="nav-tabpanel-2-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Stats">
 <figure><img src="fig/docker-desktop/spuc_stats.png" alt="Stats tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
 </div>
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 </button>
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-<div id="nav-tabpanel-3-Logs" class="tab-pane show active" aria-labelledby="nav-tab-3-Logs" role="tabpanel">
+<div id="nav-tabpanel-3-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-3-Logs">
 <figure><img src="fig/docker-desktop/alpine_logs.png" alt="Logs tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Inspect" class="tab-pane" aria-labelledby="nav-tab-3-Inspect" role="tabpanel">
+<div id="nav-tabpanel-3-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Inspect">
 <figure><img src="fig/docker-desktop/alpine_inspect.png" alt="Inspect tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-3-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Bindmounts">
 <figure><img src="fig/docker-desktop/alpine_bind.png" alt="Bind mounts tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Exec" class="tab-pane" aria-labelledby="nav-tab-3-Exec" role="tabpanel">
+<div id="nav-tabpanel-3-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Exec">
 <figure><img src="fig/docker-desktop/alpine_exec.png" alt="Exec tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Files" class="tab-pane" aria-labelledby="nav-tab-3-Files" role="tabpanel">
+<div id="nav-tabpanel-3-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Files">
 <figure><img src="fig/docker-desktop/alpine_files.png" alt="Files tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Stats" class="tab-pane" aria-labelledby="nav-tab-3-Stats" role="tabpanel">
+<div id="nav-tabpanel-3-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Stats">
 <figure><img src="fig/docker-desktop/alpine_stats.png" alt="Stats tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
 </div>
 </div>
@@ -881,8 +881,8 @@ <h3 class="callout-title">Key Points</h3>
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   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/docker-hub.html b/docker-hub.html
index d063f7e..9eaae67 100644
--- a/docker-hub.html
+++ b/docker-hub.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -329,7 +329,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       <div class="d-none d-sm-none d-md-block">
         <a class="chapter-link" href="docker-cli-advanced.html" rel="prev">
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>
-          Previous: Using the full power
+          Previous: Sharing information
         </a>
         <a class="chapter-link float-end" href="creating-container-images.html" rel="next">
           Next: Creating Your Own...
@@ -338,7 +338,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>The Docker Hub</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-hub.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -583,7 +583,7 @@ <h3 class="callout-title">Key Points</h3>
       <div class="d-none d-sm-none d-md-block">
         <a class="chapter-link" href="docker-cli-advanced.html" rel="prev">
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>
-          Previous: Using the full power
+          Previous: Sharing information
         </a>
         <a class="chapter-link float-end" href="creating-container-images.html" rel="next">
           Next: Creating Your Own...
@@ -632,8 +632,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/docker-hub.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/docker-hub.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/images.html b/images.html
index 07e3868..3f35641 100644
--- a/images.html
+++ b/images.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -519,7 +519,7 @@ <h3 id="docker-desktop-figure-40">Figure 40</h3>
 <hr class="half-width">
 <h3 id="docker-cli-toolkit-figure-1">Figure 1</h3>
 <p aria-hidden="true">Image 1 of 1: ‘A diagram showing the syntactic structure of a Docker command’</p>
-<figure><img src="fig/docker_cmd.png" alt="A diagram showing the syntactic structure of a Docker command" class="figure mx-auto d-block"></figure><hr></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Using the full power of the Docker CLIData in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></a></h2>
+<figure><img src="fig/docker_cmd.png" alt="A diagram showing the syntactic structure of a Docker command" class="figure mx-auto d-block"></figure><hr></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Sharing information with containers</a></h2>
 <hr class="half-width"></section><section id="docker-hub"><h2 class="section-heading"><a href="docker-hub.html">The Docker Hub</a></h2>
 <hr class="half-width">
 <h3 id="docker-hub-figure-1">Figure 1</h3>
@@ -592,8 +592,8 @@ <h3 id="docker-hub-figure-7">Figure 7</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/images.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/images.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
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diff --git a/index.html b/index.html
index a848833..fd07af8 100644
--- a/index.html
+++ b/index.html
@@ -236,7 +236,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -440,7 +440,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Windows
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Installation of Docker on Microsoft Windows comprises two central
 steps:</p>
@@ -530,7 +530,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Mac
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Please install docker following these <a href="https://docs.docker.com/desktop/install/mac-install/" class="external-link">instructions</a>.</p>
 </div>
@@ -544,7 +544,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Linux
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Installation on Linux requires two steps:</p>
 <ul><li>Installation of Docker Engine</li>
@@ -690,8 +690,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
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   "identifier": "https://uomresearchit.github.io/docker-introduction/index.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor-notes.html b/instructor-notes.html
index 3cc5a7a..70748b9 100644
--- a/instructor-notes.html
+++ b/instructor-notes.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -433,8 +433,8 @@ <h1>Instructor Notes</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor-notes.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor-notes.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/404.html b/instructor/404.html
index 0d5568d..c54ed71 100644
--- a/instructor/404.html
+++ b/instructor/404.html
@@ -240,7 +240,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html" class="external-link">4. Using the full power of the Docker CLI</a>
+        <a href="https://uomresearchit.github.io/docker-introduction/docker-cli-advanced.html" class="external-link">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -382,8 +382,8 @@ <h1>Page not found</h1>
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-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/CODE_OF_CONDUCT.html b/instructor/CODE_OF_CONDUCT.html
index 44fa76b..ad58097 100644
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+++ b/instructor/CODE_OF_CONDUCT.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -322,7 +322,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Contributor Code of Conduct</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/CODE_OF_CONDUCT.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -403,8 +403,8 @@ <h1>Contributor Code of Conduct</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/CODE_OF_CONDUCT.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/CODE_OF_CONDUCT.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/LICENSE.html b/instructor/LICENSE.html
index fac166e..c0871a2 100644
--- a/instructor/LICENSE.html
+++ b/instructor/LICENSE.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -322,7 +322,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Licenses</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/LICENSE.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -451,8 +451,8 @@ <h1>Licenses</h1>
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   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/LICENSE.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/aio.html b/instructor/aio.html
index 0901adb..58fb23e 100644
--- a/instructor/aio.html
+++ b/instructor/aio.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -378,7 +378,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         
 <section id="aio-introduction"><p>Content from <a href="introduction.html">Introducing Containers</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/introduction.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 20 minutes</p>
@@ -671,7 +671,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-desktop"><p>Content from <a href="docker-desktop.html">Docker Desktop</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-desktop.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 20 minutes</p>
@@ -837,22 +837,22 @@ <h3 class="tab-header" id="nav-tab-heading-1-Stats">
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 </nav><div id="nav-tabContent-1" class="tab-content">
-<div id="nav-tabpanel-1-Logs" class="tab-pane show active" aria-labelledby="nav-tab-1-Logs" role="tabpanel">
+<div id="nav-tabpanel-1-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-1-Logs">
 <figure><img src="../fig/docker-desktop/hello_log.png" alt="Logs tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Inspect" class="tab-pane" aria-labelledby="nav-tab-1-Inspect" role="tabpanel">
+<div id="nav-tabpanel-1-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Inspect">
 <figure><img src="../fig/docker-desktop/hello_inspect.png" alt="Inspect tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-1-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Bindmounts">
 <figure><img src="../fig/docker-desktop/hello_bind.png" alt="Bind mounts tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Exec" class="tab-pane" aria-labelledby="nav-tab-1-Exec" role="tabpanel">
+<div id="nav-tabpanel-1-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Exec">
 <figure><img src="../fig/docker-desktop/hello_exec.png" alt="Exec tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Files" class="tab-pane" aria-labelledby="nav-tab-1-Files" role="tabpanel">
+<div id="nav-tabpanel-1-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Files">
 <figure><img src="../fig/docker-desktop/hello_files.png" alt="Files tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-1-Stats" class="tab-pane" aria-labelledby="nav-tab-1-Stats" role="tabpanel">
+<div id="nav-tabpanel-1-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Stats">
 <figure><img src="../fig/docker-desktop/hello_stats.png" alt="Stats tab in container from hello-world image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -934,22 +934,22 @@ <h3 class="tab-header" id="nav-tab-heading-2-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-2" class="tab-content">
-<div id="nav-tabpanel-2-Logs" class="tab-pane show active" aria-labelledby="nav-tab-2-Logs" role="tabpanel">
+<div id="nav-tabpanel-2-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-2-Logs">
 <figure><img src="../fig/docker-desktop/spuc_log.png" alt="Logs tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Inspect" class="tab-pane" aria-labelledby="nav-tab-2-Inspect" role="tabpanel">
+<div id="nav-tabpanel-2-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Inspect">
 <figure><img src="../fig/docker-desktop/spuc_inspect.png" alt="Inspect tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-2-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Bindmounts">
 <figure><img src="../fig/docker-desktop/spuc_bind.png" alt="Bind mounts tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Exec" class="tab-pane" aria-labelledby="nav-tab-2-Exec" role="tabpanel">
+<div id="nav-tabpanel-2-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Exec">
 <figure><img src="../fig/docker-desktop/spuc_exec.png" alt="Exec tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Files" class="tab-pane" aria-labelledby="nav-tab-2-Files" role="tabpanel">
+<div id="nav-tabpanel-2-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Files">
 <figure><img src="../fig/docker-desktop/spuc_files.png" alt="Files tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-2-Stats" class="tab-pane" aria-labelledby="nav-tab-2-Stats" role="tabpanel">
+<div id="nav-tabpanel-2-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Stats">
 <figure><img src="../fig/docker-desktop/spuc_stats.png" alt="Stats tab in container from spuc image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -1129,22 +1129,22 @@ <h3 class="tab-header" id="nav-tab-heading-3-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-3" class="tab-content">
-<div id="nav-tabpanel-3-Logs" class="tab-pane show active" aria-labelledby="nav-tab-3-Logs" role="tabpanel">
+<div id="nav-tabpanel-3-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-3-Logs">
 <figure><img src="../fig/docker-desktop/alpine_logs.png" alt="Logs tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Inspect" class="tab-pane" aria-labelledby="nav-tab-3-Inspect" role="tabpanel">
+<div id="nav-tabpanel-3-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Inspect">
 <figure><img src="../fig/docker-desktop/alpine_inspect.png" alt="Inspect tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-3-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Bindmounts">
 <figure><img src="../fig/docker-desktop/alpine_bind.png" alt="Bind mounts tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Exec" class="tab-pane" aria-labelledby="nav-tab-3-Exec" role="tabpanel">
+<div id="nav-tabpanel-3-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Exec">
 <figure><img src="../fig/docker-desktop/alpine_exec.png" alt="Exec tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Files" class="tab-pane" aria-labelledby="nav-tab-3-Files" role="tabpanel">
+<div id="nav-tabpanel-3-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Files">
 <figure><img src="../fig/docker-desktop/alpine_files.png" alt="Files tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
-<div id="nav-tabpanel-3-Stats" class="tab-pane" aria-labelledby="nav-tab-3-Stats" role="tabpanel">
+<div id="nav-tabpanel-3-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Stats">
 <figure><img src="../fig/docker-desktop/alpine_stats.png" alt="Stats tab in container from alpine image." class="figure mx-auto d-block"></figure>
 </div>
 </div>
@@ -1190,7 +1190,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-cli-toolkit"><p>Content from <a href="docker-cli-toolkit.html">Building our Docker CLI toolkit</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-toolkit.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 198 minutes</p>
@@ -1739,7 +1739,7 @@ <h3 class="accordion-header" id="headingSpoiler1">
   Logs
   </h3>
 </button>
-<div id="collapseSpoiler1" class="accordion-collapse collapse" data-bs-parent="#accordionSpoiler1" aria-labelledby="headingSpoiler1">
+<div id="collapseSpoiler1" class="accordion-collapse collapse" aria-labelledby="headingSpoiler1" data-bs-parent="#accordionSpoiler1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2196,9 +2196,9 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </div>
 </div>
-</section></section><section id="aio-docker-cli-advanced"><p>Content from <a href="docker-cli-advanced.html">Using the full power of the Docker CLI</a></p>
+</section></section><section id="aio-docker-cli-advanced"><p>Content from <a href="docker-cli-advanced.html">Sharing information with containers</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-advanced.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 198 minutes</p>
@@ -2216,9 +2216,7 @@ <h2 class="card-header">Overview</h2>
 <div class="inner">
 <h3 class="card-title">Questions</h3>
 <ul>
-<li>What actually happens when I run a container?</li>
-<li>How can I control the behaviour of containers?</li>
-<li>How do I get data in and out of containers?</li>
+<li>How do I get information in and out of containers?</li>
 </ul>
 </div>
 </div>
@@ -2228,85 +2226,78 @@ <h3 class="card-title">Questions</h3>
 <div class="inner bordered">
 <h3 class="card-title">Objectives</h3>
 <ul>
-<li>Learn the lifecycle of Docker containers</li>
-<li>Learn about Entrypoints and Commands and how to manipulate them</li>
 <li>Learn how to use files with container using mounts and volumes</li>
+<li>Learn how to set environment variables and pass parameters to
+containers</li>
 </ul>
 </div>
 </div>
 </div>
 </div>
 </div>
-<div class="section level1">
-<h1 id="data-in-containers">Data in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a>
-</h1>
-<p>In the earlier section on Docker Desktop, we learned how to interact
-with containers and used this to have a look at the
-unicorn_sightings.txt file.</p>
-<p>It is quite annoying that the file does not persist between runs of
-the container! Also, with the file being in the container, we can’t
-(easily) do much with it.</p>
-<p>This is where the Docker CLI starts to shine.</p>
-<div class="section level2">
-<h2 id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a>
+<section><h2 class="section-heading" id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a>
 </h2>
+<hr class="half-width">
+<p>In the earlier sections we interacted with the SPUC container and
+made changes to the <code>print.config</code> file. We also registered
+some unicorn sightings using the API, which were recorded in the
+<code>unicorn_sightings.txt</code> file. However, we lost all those
+changes when we stopped the container.</p>
 <p>Docker containers are naturally isolated from the host system,
-meaning that they have their own filesystems and cannot access the host
-filesystem.</p>
-<p>They are also ephemeral, meaning that they are designed to be
-temporary and are destroyed when they are stopped.</p>
+meaning that they have their own filesystem, and cannot access the host
+filesystem. They are also designed to be temporary, and are destroyed
+when they are stopped.</p>
 <p>This is mostly a good thing, as it means that containers are
 lightweight and can be easily recreated, but we can’t be throwing our
 unicorn sightings away like this!</p>
-<p>Luckily, Docker has methods for allowing containers to persist
+<p>Also, with the file being in the container, we can’t (easily) do much
+with it. Luckily, Docker has methods for allowing containers to persist
 data.</p>
-<div class="section level3">
-<h3 id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a>
-</h3>
-<p>The first way to allow a container to access the host filesystem is
-by using a <code>volume</code>. A volume is a specially designated
-directory on the host filesystem which is shared with the container,
-hidden away deep in the host filesystem.</p>
-<p>Volumes are very tightly controlled by Docker, and are designed to be
-used for sharing data between containers, or for persisting data between
-runs of a container. They are very useful, but can be a bit tricky to
-use.</p>
+</section><section><h2 class="section-heading" id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a>
+</h2>
+<hr class="half-width">
+<p>One way to allow a container to access the host filesystem is by
+using a <code>volume</code>. A volume is a specially designated
+directory hidden away deep in the host filesystem. This directory is
+shared with the container.</p>
+<p>Volumes are very tightly controlled by Docker. They are designed to
+be used for sharing data between containers, or for persisting data
+between runs of a container.</p>
 <p>Let’s have a look at how we can use a volume to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+We do this by modifying our <code>run</code> command to include a
+<code>-v</code> (for volume) flag, a volume name and a path inside the
 container.</p>
-<p>We do this by modifying our <code>docker run</code> command to
-include a <code>-v</code> (for volume) flag, a volume name and a path
-inside the container.</p>
-<p><strong>Note</strong>: You have to be <em>really</em> careful with
-the syntax for this command. See the challenge box below for common
-mistakes (and their resolution).</p>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code><span><span class="va">f1bd2bb9062348b6a1815f5076fcd1b79e603020c2d58436408c6c60da7e73d2</span></span></code></pre>
 </div>
-<p>Ok! But what is happening?</p>
-<p>We can see what containers we have created using:</p>
+<p>Ok! But what is happening? We can see what containers we have created
+using:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> docker volume ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">docker</span> volume ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>local     spuc-volume</code></pre>
 </div>
-<p>And we can see information about the volume using:</p>
+<div class="section level3 spolier">
+<h3 id="inspecting-the-volume">Inspecting the volume<a class="anchor" aria-label="anchor" href="#inspecting-the-volume"></a>
+</h3>
+<p>We can see more information about the volume using:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> docker volume inspect spuc-volume</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">docker</span> volume inspect spuc-volume</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2325,18 +2316,18 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Which shows us that the volume is stored in
 <code>/var/lib/docker/volumes/spuc-volume/_data</code> on the host
-filesystem. Which you can visit if you have superuser permissions
-(sudo).</p>
-<p>But what about the container? Has this actually worked? Let’s record
-some sightings and see if they persist between runs.</p>
-<p>First, what’s that over there?? A unicorn! No… three unicorns! Let’s
+filesystem. You can visit and edit files there if you have superuser
+permissions (sudo).</p>
+</div>
+<p>But what about the container? Has this actually worked?</p>
+<p>First… what’s that over there?? A unicorn! No… three unicorns! Let’s
 record these sightings.</p>
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2349,142 +2340,142 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuhc</code></pre>
+<pre class="output" tabindex="0"><code>count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
-<p>Now for our test, we will stop the container, run it again and check
-the sightings file.</p>
+<p>Now, for our test, we will stop the container. Since we used the
+<code>-rm</code> flag, the container will also be deleted.</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">docker</span> ps <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuh</code></pre>
-</div>
-<p>So there we have it! The sightings persist between runs of the
-container. This is a great way to keep data between runs of a container,
-but watch out for the syntax!</p>
-<div id="common-mistakes-with-volumes" class="callout discussion">
-<div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<pre class="output" tabindex="0"><code>spuc_container
+CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES</code></pre>
 </div>
-<div id="common-mistakes-with-volumes" class="callout-inner">
-<h3 class="callout-title">Common mistakes with volumes</h3>
-<div class="callout-content">
-<p>Given you are in a directory containing a directory named
-<code>spuc</code>, what will happen when you run the following
-commands?</p>
-<ol style="list-style-type: upper-alpha">
-<li><p>$ docker run -v ./spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ./spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spucs:/foo spuc:latest</p></li>
-</ol>
+<p>This would have been game over, but we used a volume. Let’s run it
+again and check the sightings file.</p>
+<div class="codewrapper sourceCode" id="cb13">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span>
+<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>536a6d2f73061aa94729df3536ee86b60dcd68f4652bfbdc9e4cfa9c6cfda168
+count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
+<p>It’s worked! The unicorn sightings are still there! The only problem
+is that the file is still in the container, and we can’t easily access
+it from the host filesystem.</p>
+</section><section><h2 class="section-heading" id="bind-mounts">Bind mounts<a class="anchor" aria-label="anchor" href="#bind-mounts"></a>
+</h2>
+<hr class="half-width">
+<p>Another way to allow a container to access the host filesystem is by
+using a <code>bind mount</code>. A bind mount is a direct mapping of a
+specified directory on the host filesystem to a directory in the
+container filesystem. This allows you to directly access files on the
+host filesystem from the container, but it has its own challenges.</p>
+<p>Let’s have a look at how we can use a bind mount to persist the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+Confusingly, bind mounting is also done using the <code>-v</code> flag.
+However, instead of a name for the volume, we have to specify a path on
+the host filesystem.</p>
+<p><strong>Note:</strong> In older versions of Docker the path had to be
+<em>absolute</em>; <em>relative</em> paths are now supported.</p>
+<div class="codewrapper sourceCode" id="cb15">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
-<div class="accordion-item">
-<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
-  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
-</button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
-<div class="accordion-body">
-<ol style="list-style-type: upper-alpha">
-<li>The path to the volume must be an absolute path, not a relative
-path. You can use the $PWD environment variable to get the current
-working directory. This will create a (root owned) directory in the
-current working directory, which is not what you want. Use “sudo rm -rf
-./spuc-volume” to remove the volume and try again.</li>
-<li>This is the correct syntax for creating a volume. This will create a
-volume called spuc-volume and mount it to the /foo directory in the
-container.</li>
-<li>Because ./spuc is not an absolute path, this will create a new
-volume called spuc and mount it to the /foo directory in the container.
-This is not what you want. Use “sudo rm -rf ./spuc” to remove the volume
-and try again.</li>
-<li>This is valid syntax but not for creating a volume! This will create
-a bind mount instead. More on these next.</li>
-<li>This will create a new volume called spuc<strong>s</strong> and
-mount it to the /foo directory in the container. This is not what you
-want. Use “sudo rm -rf ./spucs” to remove the volume and try again.</li>
-</ol>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>spuc_container
+79620ff93fdd8135dcc7f595223144c075a9df53fc32f2ce799ee8e338b9df41</code></pre>
 </div>
+<p>The directory <code>spuc/output</code> likely did not exist in your
+current working directory, so Docker created one. It is currently empty,
+as you can see by listing the contents with <code>ls spuc/output</code>.
+If we now record a unicorn sighting, we can see the records file in the
+directory.</p>
+<div class="codewrapper sourceCode" id="cb17">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{message:"Unicorn sighting recorded!"}
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
+<p>and the file is still there even after stopping the container</p>
+<div class="codewrapper sourceCode" id="cb19">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="fu">ls</span> spuc/output</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code><span><span class="va">spuc_container</span></span>
+<span><span class="va">unicorn_sightings.txt</span></span></code></pre>
 </div>
-<div class="section level3">
-<h3 id="bind-mounting-directories">Bind mounting directories<a class="anchor" aria-label="anchor" href="#bind-mounting-directories"></a>
-</h3>
-<p>The second way to allow a container to access the host filesystem is
-by using a <code>bind mount</code>. A bind mount is a direct mapping of
-a directory on the host filesystem to a directory in the container
-filesystem.</p>
-<p>This can be appealing, as it allows you to directly access files on
-the host filesystem from the container, but it has its own
-challenges.</p>
-<p>Let’s have a look at how we can use a bind mount to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
-container.</p>
-<p>Confusingly, bind mounting is also done using the <code>-v</code>
-flag, but with a different syntax. We specify an
-<strong>absolute</strong> path to the directory on the host filesystem,
-followed by a colon, followed by the path to the directory in the
-container filesystem.</p>
-<p>It can be annoying to type the full path to a directory, so we can
-use the <code>$PWD</code> environment variable to get the current
-working directory.</p>
-<div class="codewrapper sourceCode" id="cb13">
+<p>If we run the container again, we can see the file is still
+there.</p>
+<div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container </span>
-<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/spuc:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb13-3"><a href="#cb13-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
-<span id="cb13-4"><a href="#cb13-4" tabindex="-1"></a><span class="ex">$</span> tree spuc/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span>
+<span id="cb21-2"><a href="#cb21-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>spuc/
-└── unicorn_sightings.txt</code></pre>
+<pre class="output" tabindex="0"><code>3dd079c21845fc36ddc3b20fd525790a1e194c198c4b98337f4ed82bfc7a9755
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
-<p>So now we can access the /code/output directory in the container on
-the host filesystem. This is totally functional way to persist data
-between runs of a container but there are downsides.</p>
-<p>To illusrate this, let’s see what the permissions are on the file we
+<p>So we not only managed to persist the data between runs of the
+container, but we can also access the file when the container is not
+running. This is great!… but there are downsides.</p>
+<p>To illustrate this, let’s see what the permissions are on the file we
 just created.</p>
-<div class="codewrapper sourceCode" id="cb15">
+<div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="fu">ls</span> <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>-rw-r--r-- 1 root root 57 Oct 11 14:14 spuc/unicorn_sightings.txt</code></pre>
 </div>
-<p>Argh, the file is owned by root!</p>
-<p>This is because the container runs as root, and so any files created
-by the container are owned by root. This can be a problem, as you will
-not have permission to access the file without using
-<code>sudo</code>.</p>
+<p>Argh, the file is owned by root! This is because the container runs
+as root, and so any files created by the container are owned by root.
+This can be a problem, as you will not have permission to access the
+file without using <code>sudo</code>.</p>
 <p>This is a common problem with bind mounts, and can be a bit of a pain
 to deal with. You can change the ownership of the file using
 <code>sudo chown</code>, but this can be a bit of a hassle.</p>
@@ -2492,79 +2483,144 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 are not managed by Docker. The management of bind mounts is left to the
 user.</p>
 <p>Really, neither volumes nor bind mounts are perfect, but they are
-both useful tools for persisting data between runs of a container and
-have both allowed us to keep the unicorn_sightings.txt file between runs
-of the container.</p>
-<p>Later in these lessons we will see some more ergonomic ways to work
-with volumes and bind mounts.</p>
-</div>
-</div>
-<div class="section level2">
-<h2 id="sharing-files-with-containers">Sharing files with containers<a class="anchor" aria-label="anchor" href="#sharing-files-with-containers"></a>
-</h2>
-<p>Earlier, we looked at how to change the config file in SPUC to enable
-exporting. This was a bit of a hassle, as we had to use the Docker
-Desktop interface to do this and it did not persist between runs of the
+both useful tools for persisting data between runs of a container.</p>
+<div class="section level3">
+<h3 id="bind-mount-files">Bind mount files<a class="anchor" aria-label="anchor" href="#bind-mount-files"></a>
+</h3>
+<p>Earlier, we looked at how to change the print.config file in SPUC to
+format the logs. This was a bit difficult, as we had to do it from
+inside the container, and it did not persist between runs of the
 container.</p>
 <p>We now have the tools to address this! We can use a bind mount to
 share the config file with the container.</p>
-<p>Let’s have a look at how we can do this. First we need to make the
-config file itself.</p>
-<p>The SPUC README on dockerhub tells us that the config file should be
-in the following format:</p>
-<pre class="plaintext"><code>::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}</code></pre>
-<p>And should be present at <code>/code/config/print.config</code>.</p>
-<p>Let’s get to it then. First we need to make the file (on the
-host).</p>
-<div class="codewrapper sourceCode" id="cb18">
+<p>First we need to make the config file itself. Let’s create a file
+with the following content:</p>
+<div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> echo <span class="st">"::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: {time} Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
-<p>Now we can bind mount this file to the container. Again we will use
-<code>-v</code> and the <code>$PWD</code> environment variable to get
-the current working directory. This time, however, we will specify a
-specific file to mount, not a directory.</p>
-<div class="codewrapper sourceCode" id="cb19">
+<p>Now, to share it with the container, we need to put it in the path
+<code>/spuc/config/print.config</code>. Again we will use
+<code>-v</code>, but we will specify the path to the file, instead of a
+directory.</p>
+<div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<p>Now if we check the logs of the container, we can see that the config
-file has been loaded correctly and that the print format has been
-changed.</p>
-<p>First, let’s record another sighting, then check the logs.</p>
-<div class="codewrapper sourceCode" id="cb20">
+<p>Now let’s check if this worked. For that, we need to record another
+sighting and then check the logs.</p>
+<div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=jupyter\&amp;brightness=100</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>[...]
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
 [...]
-::::: (2024-10-11 14:29:07.548965) Unicorn spotted at moon!! Brightness: 100 iuhc</code></pre>
+::::: 2024-10-16 10:53:13.449393 Unicorn number 4 spotted at jupyter! Brightness: 100 iuhc</code></pre>
 </div>
-<p>Fantastic! We have now managed to share a file with the container,
-and have changed the behaviour of the container using this file.</p>
-<div class="section level3">
-<h3 id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a>
+<p>Fantastic! We have now managed to share a file with the container.
+Not only that, but because we created the file before mounting it to the
+container, we are the owners, and can modify it. Changes to the file
+will reflect immediately on the container.</p>
+<p>For example, let’s edit the file to get rid of the date:</p>
+<div class="codewrapper sourceCode" id="cb29">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<p>We have learned about volumes and bind mounts, two ways to allow a
-container to access the host filesystem. We have used these to persist
-data between runs of a container and to share files with a
-container.</p>
-<p>They can both be a bit tricky to use, but are very useful tools for
-working with containers and have helped us get SPUC working much more
-like we want it to.</p>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+</div>
+<p>Now let’s register a sighting, and look at the logs:</p>
+<div class="codewrapper sourceCode" id="cb30">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=venus\&amp;brightness=148</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
+</div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
+[...]
+::::: Unicorn number 7 spotted at venus! Brightness: 148 iuhc</code></pre>
+</div>
+<p>It almost seems too easy! We now have a print configuration and
+unicorn sighting record that persists between runs of the container.</p>
+<p><strong>Warning</strong>: We <em>replaced</em> the file in the
+container with the file from the host filesystem. We could do the same
+with a whole directory, but be careful not to overwrite important files
+in the container!</p>
+<div id="common-mistakes-with-volumes" class="callout challenge">
+<div class="callout-square">
+<i class="callout-icon" data-feather="zap"></i>
+</div>
+<div id="common-mistakes-with-volumes" class="callout-inner">
+<h3 class="callout-title">Common mistakes with volumes</h3>
+<div class="callout-content">
+<p>You have to be <em>really</em> careful with the syntax for volumes
+and mounts.</p>
+<p>Let’s imagine you are in a path containing a directory
+<code>spuc</code>, with an empty sub-directory <code>output</code> and a
+<code>print.config</code> file. What do you think will happen when you
+run the following commands?</p>
+<ol style="list-style-type: upper-alpha">
+<li><code>docker run -v spuc-vol spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spucs/output:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc-vol:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc:/spuc spuacv/spuc:latest</code></li>
+<li><code>docker run -v print.config:/spuc/config/print.config spuacv/spuc:latest</code></li>
+</ol>
 </div>
 </div>
-<div class="section level2">
-<h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a>
+</div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div class="accordion-body">
+<ol style="list-style-type: upper-alpha">
+<li><p><strong>Problem:</strong> We provided a volume name, but not a
+path to mount it to. If the volume already existed, this will mount it
+on <code>/spuc-vol</code>. If the volume did not exist, it will create a
+directory <code>/spuc-vol</code> in the container, but it wont
+persist!<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Stop it and try again.</p></li>
+<li><p><strong>Problem:</strong> You misspelled the path! This will
+create a new directory called spuc<strong>s</strong> and mount it.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spucs</code> to remove the
+directory and try again.</p></li>
+<li><p><strong>Problem:</strong> At first, it seems like we will create
+a volume. However, we have provided a path, not a name for the volume.
+Therefore, Docker thinks you want a bind mount, and will create a (root
+owned) directory called <code>spuc-vol</code>.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spuc-volume</code> to
+remove the directory and try again.</p></li>
+<li><p><strong>Problem:</strong> This is valid syntax for a bind mount.
+It will take the almost empty <code>spuc</code> directory in your
+filesystem and mount it to <code>/spuc</code> in the container. However,
+it replaced everything in there in the process! Your command most likely
+failed because it could not find <code>/spuc/spuc.py</code>.<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Try again.</p></li>
+<li><p><strong>Problem:</strong> We forgot to use a path for the file!
+This will try to create a new volume called <code>print.config</code>
+and mount it to <code>/spuc/config/print.config</code>. However, it will
+most likely fail because <code>print.config</code> is not a
+directory.<br><strong>Fix:</strong> Use <code>docker volume rm print.config</code> to
+remove the volume and try again.</p></li>
+</ol>
+</div>
+</div>
+</div>
+</div>
+</div>
+</section><section><h2 class="section-heading" id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a>
 </h2>
+<hr class="half-width">
 <p>One other interesting reading from the SPUC README is the presence of
 an environment variable, <code>EXPORT</code> which can be set to
 <code>True</code> to enable an API endpoint for exporting the unicorn
@@ -2574,12 +2630,12 @@ <h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-l
 <p>Thankfully this is quite straightforward, we can use the
 <code>-e</code> flag to set an environment variable in a container.</p>
 <p>Modifying our run command again:</p>
-<div class="codewrapper sourceCode" id="cb22">
+<div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb32-2"><a href="#cb32-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest</span>
+<span id="cb32-3"><a href="#cb32-3" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2593,10 +2649,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ::::: Or 'curl localhost:8321/export' to download the unicorn sightings file!</code></pre>
 </div>
 <p>And now we can see that the export endpoint is available!</p>
-<div class="codewrapper sourceCode" id="cb24">
+<div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2613,10 +2669,9 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Environment variables are a very common tool for configuring
 containers. They are used to set things like API keys, database
 connection strings, and other configuration options.</p>
-</div>
-<div class="section level2">
-<h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a>
+</section><section><h2 class="section-heading" id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a>
 </h2>
+<hr class="half-width">
 <p>Finally, we must address a very serious shortcoming of the SPUC
 container. It is recording the brightness of the unicorns in Imperial
 Unicorn Hoove Candles (iuhc)! This is a very outdated unit and we
@@ -2625,13 +2680,13 @@ <h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anch
 the container to set the units to metric. This is done by passing a
 parameter to the container when it is run, overriding the default
 command.</p>
-<div class="codewrapper sourceCode" id="cb26">
+<div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest <span class="at">--units</span> iulu</span>
-<span id="cb26-3"><a href="#cb26-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb26-4"><a href="#cb26-4" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest <span class="at">--units</span> iulu</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export/</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -2654,21 +2709,21 @@ <h3 class="callout-title">Callout</h3>
 different command in the container, or if you want to run the container
 interactively.</p>
 <p>You may recall:</p>
-<div class="codewrapper sourceCode" id="cb28">
+<div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">docker</span> inspect ghcr.io/uomresearchit/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
-<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /code/spuc.py] Command: [--units iuhc]</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">docker</span> inspect spuacv/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
+<span id="cb38-2"><a href="#cb38-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /spuc/spuc.py] Command: [--units iuhc]</span></code></pre>
 </div>
-<p>That SPUC has an entrypoint of <code>python /code/spuc.py</code>
+<p>That SPUC has an entrypoint of <code>python /spuc/spuc.py</code>
 making it hard to interact with. We can override this using the
 <code>--entrypoint</code> flag.</p>
-<div class="codewrapper sourceCode" id="cb29">
+<div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="discussion2" class="callout discussion">
+<div id="discussion1" class="callout discussion">
 <div class="callout-square">
 <i class="callout-icon" data-feather="message-circle"></i>
 </div>
@@ -2686,23 +2741,23 @@ <h3 class="callout-title">Challenge</h3>
 <tbody>
 <tr class="odd">
 <td>A</td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 <td></td>
 </tr>
 <tr class="even">
 <td>B</td>
-<td><code>python /code/spuc.py</code></td>
+<td><code>python /spuc/spuc.py</code></td>
 <td><code>--units iuhc</code></td>
 </tr>
 <tr class="odd">
 <td>C</td>
 <td><code>python</code></td>
-<td><code>/code/spuc.py --units iuhc</code></td>
+<td><code>/spuc/spuc.py --units iuhc</code></td>
 </tr>
 <tr class="even">
 <td>D</td>
 <td></td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 </tr>
 </tbody>
 </table>
@@ -2714,7 +2769,7 @@ <h3 class="callout-title">Challenge</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>These are all valid combinations! The best choice depends on the use
 case.</p>
@@ -2737,10 +2792,9 @@ <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </div>
 </div>
 </div>
-</div>
-<div class="section level2">
-<h2 id="summary-1">Summary<a class="anchor" aria-label="anchor" href="#summary-1"></a>
+</section><section><h2 class="section-heading" id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a>
 </h2>
+<hr class="half-width">
 <p>In this section, we have learned about volumes and bind mounts, two
 ways to allow a container to access the host filesystem. We have used
 these to persist data between runs of a container and to share files
@@ -2766,10 +2820,9 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </div>
 </div>
-</div>
-</div></section><section id="aio-docker-hub"><p>Content from <a href="docker-hub.html">The Docker Hub</a></p>
+</section></section><section id="aio-docker-hub"><p>Content from <a href="docker-hub.html">The Docker Hub</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-hub.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 20 minutes</p>
@@ -3027,7 +3080,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-creating-container-images"><p>Content from <a href="creating-container-images.html">Creating Your Own Container Images</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/creating-container-images.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 198 minutes</p>
@@ -3496,7 +3549,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-docker-compose"><p>Content from <a href="docker-compose.html">Using Docker Compose</a></p>
 <hr>
-<p>Last updated on 2024-10-15 |
+<p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-compose.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 198 minutes</p>
@@ -4408,8 +4461,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/aio.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/aio.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/creating-container-images.html b/instructor/creating-container-images.html
index f48b441..581a510 100644
--- a/instructor/creating-container-images.html
+++ b/instructor/creating-container-images.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -338,7 +338,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Creating Your Own Container Images</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/creating-container-images.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -850,8 +850,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/creating-container-images.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/creating-container-images.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/docker-cli-advanced.html b/instructor/docker-cli-advanced.html
index 2e9f214..22eacfe 100644
--- a/instructor/docker-cli-advanced.html
+++ b/instructor/docker-cli-advanced.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<!-- START: inst/pkgdown/templates/layout.html --><!-- Generated by pkgdown: do not edit by hand --><html lang="en" data-bs-theme="auto"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><title>Introduction to Docker: Using the full power of the Docker CLI</title><meta name="viewport" content="width=device-width, initial-scale=1"><script src="../assets/themetoggle.js"></script><link rel="stylesheet" type="text/css" href="../assets/styles.css"><script src="../assets/scripts.js" type="text/javascript"></script><!-- mathjax --><script type="text/x-mathjax-config">
+<!-- START: inst/pkgdown/templates/layout.html --><!-- Generated by pkgdown: do not edit by hand --><html lang="en" data-bs-theme="auto"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><title>Introduction to Docker: Sharing information with containers</title><meta name="viewport" content="width=device-width, initial-scale=1"><script src="../assets/themetoggle.js"></script><link rel="stylesheet" type="text/css" href="../assets/styles.css"><script src="../assets/scripts.js" type="text/javascript"></script><!-- mathjax --><script type="text/x-mathjax-config">
     MathJax.Hub.Config({
       config: ["MMLorHTML.js"],
       jax: ["input/TeX","input/MathML","output/HTML-CSS","output/NativeMML", "output/PreviewHTML"],
@@ -232,13 +232,25 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlushcurrent">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-headingcurrent">
+      <button class="accordion-button" type="button" data-bs-toggle="collapse" data-bs-target="#flush-collapsecurrent" aria-expanded="true" aria-controls="flush-collapsecurrent">
         <span class="visually-hidden">Current Chapter</span>
         <span class="current-chapter">
-        4. Using the full power of the Docker CLI
+        4. Sharing information with containers
         </span>
-      
+      </button>
     </div><!--/div.accordion-header-->
 
+    <div id="flush-collapsecurrent" class="accordion-collapse collapse show" aria-labelledby="flush-headingcurrent" data-bs-parent="#accordionFlushcurrent">
+      <div class="accordion-body">
+        <ul><li><a href="#making-our-data-persist">Making our data persist</a></li>
+<li><a href="#volumes">Volumes</a></li>
+<li><a href="#bind-mounts">Bind mounts</a></li>
+<li><a href="#setting-the-environment">Setting the environment</a></li>
+<li><a href="#passing-parameters">Passing parameters</a></li>
+<li><a href="#summary">Summary</a></li>
+        </ul></div><!--/div.accordion-body-->
+    </div><!--/div.accordion-collapse-->
+
   </div><!--/div.accordion-item-->
 </div><!--/div.accordion-flush-->
 
@@ -325,8 +337,8 @@ <h2 class="accordion-header" id="flush-headingTwelve">
         </a>
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
-        <h1>Using the full power of the Docker CLI</h1>
-        <p>Last updated on 2024-10-15 |
+        <h1>Sharing information with containers</h1>
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-advanced.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -350,9 +362,7 @@ <h2 class="card-header">Overview</h2>
 <div class="card-body">
 <div class="inner">
 <h3 class="card-title">Questions</h3>
-<ul><li>What actually happens when I run a container?</li>
-<li>How can I control the behaviour of containers?</li>
-<li>How do I get data in and out of containers?</li>
+<ul><li>How do I get information in and out of containers?</li>
 </ul></div>
 </div>
 </div>
@@ -360,81 +370,72 @@ <h3 class="card-title">Questions</h3>
 <div class="card-body">
 <div class="inner bordered">
 <h3 class="card-title">Objectives</h3>
-<ul><li>Learn the lifecycle of Docker containers</li>
-<li>Learn about Entrypoints and Commands and how to manipulate them</li>
-<li>Learn how to use files with container using mounts and volumes</li>
+<ul><li>Learn how to use files with container using mounts and volumes</li>
+<li>Learn how to set environment variables and pass parameters to
+containers</li>
 </ul></div>
 </div>
 </div>
 </div>
 </div>
-<div class="section level1">
-<h1 id="data-in-containers">Data in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></h1>
-<p>In the earlier section on Docker Desktop, we learned how to interact
-with containers and used this to have a look at the
-unicorn_sightings.txt file.</p>
-<p>It is quite annoying that the file does not persist between runs of
-the container! Also, with the file being in the container, we can’t
-(easily) do much with it.</p>
-<p>This is where the Docker CLI starts to shine.</p>
-<div class="section level2">
-<h2 id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a></h2>
+<section><h2 class="section-heading" id="making-our-data-persist">Making our data persist<a class="anchor" aria-label="anchor" href="#making-our-data-persist"></a></h2>
+<hr class="half-width"><p>In the earlier sections we interacted with the SPUC container and
+made changes to the <code>print.config</code> file. We also registered
+some unicorn sightings using the API, which were recorded in the
+<code>unicorn_sightings.txt</code> file. However, we lost all those
+changes when we stopped the container.</p>
 <p>Docker containers are naturally isolated from the host system,
-meaning that they have their own filesystems and cannot access the host
-filesystem.</p>
-<p>They are also ephemeral, meaning that they are designed to be
-temporary and are destroyed when they are stopped.</p>
+meaning that they have their own filesystem, and cannot access the host
+filesystem. They are also designed to be temporary, and are destroyed
+when they are stopped.</p>
 <p>This is mostly a good thing, as it means that containers are
 lightweight and can be easily recreated, but we can’t be throwing our
 unicorn sightings away like this!</p>
-<p>Luckily, Docker has methods for allowing containers to persist
+<p>Also, with the file being in the container, we can’t (easily) do much
+with it. Luckily, Docker has methods for allowing containers to persist
 data.</p>
-<div class="section level3">
-<h3 id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a></h3>
-<p>The first way to allow a container to access the host filesystem is
-by using a <code>volume</code>. A volume is a specially designated
-directory on the host filesystem which is shared with the container,
-hidden away deep in the host filesystem.</p>
-<p>Volumes are very tightly controlled by Docker, and are designed to be
-used for sharing data between containers, or for persisting data between
-runs of a container. They are very useful, but can be a bit tricky to
-use.</p>
+</section><section><h2 class="section-heading" id="volumes">Volumes<a class="anchor" aria-label="anchor" href="#volumes"></a></h2>
+<hr class="half-width"><p>One way to allow a container to access the host filesystem is by
+using a <code>volume</code>. A volume is a specially designated
+directory hidden away deep in the host filesystem. This directory is
+shared with the container.</p>
+<p>Volumes are very tightly controlled by Docker. They are designed to
+be used for sharing data between containers, or for persisting data
+between runs of a container.</p>
 <p>Let’s have a look at how we can use a volume to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+We do this by modifying our <code>run</code> command to include a
+<code>-v</code> (for volume) flag, a volume name and a path inside the
 container.</p>
-<p>We do this by modifying our <code>docker run</code> command to
-include a <code>-v</code> (for volume) flag, a volume name and a path
-inside the container.</p>
-<p><strong>Note</strong>: You have to be <em>really</em> careful with
-the syntax for this command. See the challenge box below for common
-mistakes (and their resolution).</p>
 <div class="codewrapper sourceCode" id="cb1">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb1-1"><a href="#cb1-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code><span><span class="va">f1bd2bb9062348b6a1815f5076fcd1b79e603020c2d58436408c6c60da7e73d2</span></span></code></pre>
 </div>
-<p>Ok! But what is happening?</p>
-<p>We can see what containers we have created using:</p>
+<p>Ok! But what is happening? We can see what containers we have created
+using:</p>
 <div class="codewrapper sourceCode" id="cb3">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">$</span> docker volume ls</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb3-1"><a href="#cb3-1" tabindex="-1"></a><span class="ex">docker</span> volume ls</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>local     spuc-volume</code></pre>
 </div>
-<p>And we can see information about the volume using:</p>
+<div class="section level3 spolier">
+<h3 id="inspecting-the-volume">Inspecting the volume<a class="anchor" aria-label="anchor" href="#inspecting-the-volume"></a></h3>
+<p>We can see more information about the volume using:</p>
 <div class="codewrapper sourceCode" id="cb5">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">$</span> docker volume inspect spuc-volume</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb5-1"><a href="#cb5-1" tabindex="-1"></a><span class="ex">docker</span> volume inspect spuc-volume</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -453,18 +454,18 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 </div>
 <p>Which shows us that the volume is stored in
 <code>/var/lib/docker/volumes/spuc-volume/_data</code> on the host
-filesystem. Which you can visit if you have superuser permissions
-(sudo).</p>
-<p>But what about the container? Has this actually worked? Let’s record
-some sightings and see if they persist between runs.</p>
-<p>First, what’s that over there?? A unicorn! No… three unicorns! Let’s
+filesystem. You can visit and edit files there if you have superuser
+permissions (sudo).</p>
+</div>
+<p>But what about the container? Has this actually worked?</p>
+<p>First… what’s that over there?? A unicorn! No… three unicorns! Let’s
 record these sightings.</p>
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb7-1"><a href="#cb7-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
+<span id="cb7-2"><a href="#cb7-2" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb7-3"><a href="#cb7-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -477,137 +478,140 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <div class="codewrapper sourceCode" id="cb9">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb9-1"><a href="#cb9-1" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuhc</code></pre>
+<pre class="output" tabindex="0"><code>count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
 </div>
-<p>Now for our test, we will stop the container, run it again and check
-the sightings file.</p>
+<p>Now, for our test, we will stop the container. Since we used the
+<code>-rm</code> flag, the container will also be deleted.</p>
 <div class="codewrapper sourceCode" id="cb11">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb11-3"><a href="#cb11-3" tabindex="-1"></a><span class="ex">$</span> docker exec spuc_container cat /code/output/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb11-1"><a href="#cb11-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb11-2"><a href="#cb11-2" tabindex="-1"></a><span class="ex">docker</span> ps <span class="at">-a</span></span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>time,brightness,unit
-2024-10-11 10:30:18.927696,100,iuhc
-2024-10-11 10:30:25.744330,10,iuhc
-2024-10-11 10:30:30.005247,400,iuh</code></pre>
-</div>
-<p>So there we have it! The sightings persist between runs of the
-container. This is a great way to keep data between runs of a container,
-but watch out for the syntax!</p>
-<div id="common-mistakes-with-volumes" class="callout discussion">
-<div class="callout-square">
-<i class="callout-icon" data-feather="message-circle"></i>
+<pre class="output" tabindex="0"><code>spuc_container
+CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES</code></pre>
 </div>
-<div id="common-mistakes-with-volumes" class="callout-inner">
-<h3 class="callout-title">Common mistakes with volumes</h3>
-<div class="callout-content">
-<p>Given you are in a directory containing a directory named
-<code>spuc</code>, what will happen when you run the following
-commands?</p>
-<ol style="list-style-type: upper-alpha"><li><p>$ docker run -v ./spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v spuc-volume:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ./spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spuc:/foo spuc:latest</p></li>
-<li><p>$ docker run -v ${PWD}/spucs:/foo spuc:latest</p></li>
-</ol></div>
+<p>This would have been game over, but we used a volume. Let’s run it
+again and check the sightings file.</p>
+<div class="codewrapper sourceCode" id="cb13">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span>
+<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">docker</span> exec spuc_container cat /spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>536a6d2f73061aa94729df3536ee86b60dcd68f4652bfbdc9e4cfa9c6cfda168
+count,time,location,brightness,units
+0,2024-10-16 09:14:17.719447,moon,100,iuhc
+1,2024-10-16 09:14:17.726706,earth,10,iuhc
+2,2024-10-16 09:14:17.732191,mars,400,iuhc</code></pre>
+</div>
+<p>It’s worked! The unicorn sightings are still there! The only problem
+is that the file is still in the container, and we can’t easily access
+it from the host filesystem.</p>
+</section><section><h2 class="section-heading" id="bind-mounts">Bind mounts<a class="anchor" aria-label="anchor" href="#bind-mounts"></a></h2>
+<hr class="half-width"><p>Another way to allow a container to access the host filesystem is by
+using a <code>bind mount</code>. A bind mount is a direct mapping of a
+specified directory on the host filesystem to a directory in the
+container filesystem. This allows you to directly access files on the
+host filesystem from the container, but it has its own challenges.</p>
+<p>Let’s have a look at how we can use a bind mount to persist the
+<code>unicorn_sightings.txt</code> file between runs of the container.
+Confusingly, bind mounting is also done using the <code>-v</code> flag.
+However, instead of a name for the volume, we have to specify a path on
+the host filesystem.</p>
+<p><strong>Note:</strong> In older versions of Docker the path had to be
+<em>absolute</em>; <em>relative</em> paths are now supported.</p>
+<div class="codewrapper sourceCode" id="cb15">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb15-2"><a href="#cb15-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
-<div class="accordion-item">
-<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
-  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
-</button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
-<div class="accordion-body">
-<ol style="list-style-type: upper-alpha"><li>The path to the volume must be an absolute path, not a relative
-path. You can use the $PWD environment variable to get the current
-working directory. This will create a (root owned) directory in the
-current working directory, which is not what you want. Use “sudo rm -rf
-./spuc-volume” to remove the volume and try again.</li>
-<li>This is the correct syntax for creating a volume. This will create a
-volume called spuc-volume and mount it to the /foo directory in the
-container.</li>
-<li>Because ./spuc is not an absolute path, this will create a new
-volume called spuc and mount it to the /foo directory in the container.
-This is not what you want. Use “sudo rm -rf ./spuc” to remove the volume
-and try again.</li>
-<li>This is valid syntax but not for creating a volume! This will create
-a bind mount instead. More on these next.</li>
-<li>This will create a new volume called spuc<strong>s</strong> and
-mount it to the /foo directory in the container. This is not what you
-want. Use “sudo rm -rf ./spucs” to remove the volume and try again.</li>
-</ol></div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>spuc_container
+79620ff93fdd8135dcc7f595223144c075a9df53fc32f2ce799ee8e338b9df41</code></pre>
+</div>
+<p>The directory <code>spuc/output</code> likely did not exist in your
+current working directory, so Docker created one. It is currently empty,
+as you can see by listing the contents with <code>ls spuc/output</code>.
+If we now record a unicorn sighting, we can see the records file in the
+directory.</p>
+<div class="codewrapper sourceCode" id="cb17">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb17-1"><a href="#cb17-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
+<span id="cb17-2"><a href="#cb17-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{message:"Unicorn sighting recorded!"}
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
 </div>
+<p>and the file is still there even after stopping the container</p>
+<div class="codewrapper sourceCode" id="cb19">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="fu">ls</span> spuc/output</span></code></pre>
 </div>
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code><span><span class="va">spuc_container</span></span>
+<span><span class="va">unicorn_sightings.txt</span></span></code></pre>
 </div>
-<div class="section level3">
-<h3 id="bind-mounting-directories">Bind mounting directories<a class="anchor" aria-label="anchor" href="#bind-mounting-directories"></a></h3>
-<p>The second way to allow a container to access the host filesystem is
-by using a <code>bind mount</code>. A bind mount is a direct mapping of
-a directory on the host filesystem to a directory in the container
-filesystem.</p>
-<p>This can be appealing, as it allows you to directly access files on
-the host filesystem from the container, but it has its own
-challenges.</p>
-<p>Let’s have a look at how we can use a bind mount to persist the
-<code>unicorn_sightings.txt</code> file between runs of the
-container.</p>
-<p>Confusingly, bind mounting is also done using the <code>-v</code>
-flag, but with a different syntax. We specify an
-<strong>absolute</strong> path to the directory on the host filesystem,
-followed by a colon, followed by the path to the directory in the
-container filesystem.</p>
-<p>It can be annoying to type the full path to a directory, so we can
-use the <code>$PWD</code> environment variable to get the current
-working directory.</p>
-<div class="codewrapper sourceCode" id="cb13">
+<p>If we run the container again, we can see the file is still
+there.</p>
+<div class="codewrapper sourceCode" id="cb21">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb13-1"><a href="#cb13-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container </span>
-<span id="cb13-2"><a href="#cb13-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/spuc:/code/output ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb13-3"><a href="#cb13-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=mars\&amp;brightness=400</span>
-<span id="cb13-4"><a href="#cb13-4" tabindex="-1"></a><span class="ex">$</span> tree spuc/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb21-1"><a href="#cb21-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./spuc/output:/spuc/output spuacv/spuc:latest</span>
+<span id="cb21-2"><a href="#cb21-2" tabindex="-1"></a><span class="fu">cat</span> spuc/output/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>spuc/
-└── unicorn_sightings.txt</code></pre>
-</div>
-<p>So now we can access the /code/output directory in the container on
-the host filesystem. This is totally functional way to persist data
-between runs of a container but there are downsides.</p>
-<p>To illusrate this, let’s see what the permissions are on the file we
+<pre class="output" tabindex="0"><code>3dd079c21845fc36ddc3b20fd525790a1e194c198c4b98337f4ed82bfc7a9755
+count,time,location,brightness,units
+0,2024-10-16 10:31:22.222542,mars,400,iuhc</code></pre>
+</div>
+<p>So we not only managed to persist the data between runs of the
+container, but we can also access the file when the container is not
+running. This is great!… but there are downsides.</p>
+<p>To illustrate this, let’s see what the permissions are on the file we
 just created.</p>
-<div class="codewrapper sourceCode" id="cb15">
+<div class="codewrapper sourceCode" id="cb23">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb15-1"><a href="#cb15-1" tabindex="-1"></a><span class="ex">$</span> ls <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb23-1"><a href="#cb23-1" tabindex="-1"></a><span class="fu">ls</span> <span class="at">-l</span> spuc/unicorn_sightings.txt</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
 <pre class="output" tabindex="0"><code>-rw-r--r-- 1 root root 57 Oct 11 14:14 spuc/unicorn_sightings.txt</code></pre>
 </div>
-<p>Argh, the file is owned by root!</p>
-<p>This is because the container runs as root, and so any files created
-by the container are owned by root. This can be a problem, as you will
-not have permission to access the file without using
-<code>sudo</code>.</p>
+<p>Argh, the file is owned by root! This is because the container runs
+as root, and so any files created by the container are owned by root.
+This can be a problem, as you will not have permission to access the
+file without using <code>sudo</code>.</p>
 <p>This is a common problem with bind mounts, and can be a bit of a pain
 to deal with. You can change the ownership of the file using
 <code>sudo chown</code>, but this can be a bit of a hassle.</p>
@@ -615,77 +619,138 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 are not managed by Docker. The management of bind mounts is left to the
 user.</p>
 <p>Really, neither volumes nor bind mounts are perfect, but they are
-both useful tools for persisting data between runs of a container and
-have both allowed us to keep the unicorn_sightings.txt file between runs
-of the container.</p>
-<p>Later in these lessons we will see some more ergonomic ways to work
-with volumes and bind mounts.</p>
-</div>
-</div>
-<div class="section level2">
-<h2 id="sharing-files-with-containers">Sharing files with containers<a class="anchor" aria-label="anchor" href="#sharing-files-with-containers"></a></h2>
-<p>Earlier, we looked at how to change the config file in SPUC to enable
-exporting. This was a bit of a hassle, as we had to use the Docker
-Desktop interface to do this and it did not persist between runs of the
+both useful tools for persisting data between runs of a container.</p>
+<div class="section level3">
+<h3 id="bind-mount-files">Bind mount files<a class="anchor" aria-label="anchor" href="#bind-mount-files"></a></h3>
+<p>Earlier, we looked at how to change the print.config file in SPUC to
+format the logs. This was a bit difficult, as we had to do it from
+inside the container, and it did not persist between runs of the
 container.</p>
 <p>We now have the tools to address this! We can use a bind mount to
 share the config file with the container.</p>
-<p>Let’s have a look at how we can do this. First we need to make the
-config file itself.</p>
-<p>The SPUC README on dockerhub tells us that the config file should be
-in the following format:</p>
-<pre class="plaintext"><code>::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}</code></pre>
-<p>And should be present at <code>/code/config/print.config</code>.</p>
-<p>Let’s get to it then. First we need to make the file (on the
-host).</p>
-<div class="codewrapper sourceCode" id="cb18">
+<p>First we need to make the config file itself. Let’s create a file
+with the following content:</p>
+<div class="codewrapper sourceCode" id="cb25">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb18-1"><a href="#cb18-1" tabindex="-1"></a><span class="ex">$</span> echo <span class="st">"::::: {time} Unicorn spotted at {location}!! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb25-1"><a href="#cb25-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: {time} Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
-<p>Now we can bind mount this file to the container. Again we will use
-<code>-v</code> and the <code>$PWD</code> environment variable to get
-the current working directory. This time, however, we will specify a
-specific file to mount, not a directory.</p>
-<div class="codewrapper sourceCode" id="cb19">
+<p>Now, to share it with the container, we need to put it in the path
+<code>/spuc/config/print.config</code>. Again we will use
+<code>-v</code>, but we will specify the path to the file, instead of a
+directory.</p>
+<div class="codewrapper sourceCode" id="cb26">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb19-1"><a href="#cb19-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb19-2"><a href="#cb19-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output spuacv/spuc:latest</span></code></pre>
 </div>
-<p>Now if we check the logs of the container, we can see that the config
-file has been loaded correctly and that the print format has been
-changed.</p>
-<p>First, let’s record another sighting, then check the logs.</p>
-<div class="codewrapper sourceCode" id="cb20">
+<p>Now let’s check if this worked. For that, we need to record another
+sighting and then check the logs.</p>
+<div class="codewrapper sourceCode" id="cb27">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb20-1"><a href="#cb20-1" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=moon\&amp;brightness=100</span>
-<span id="cb20-2"><a href="#cb20-2" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb27-1"><a href="#cb27-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=jupyter\&amp;brightness=100</span>
+<span id="cb27-2"><a href="#cb27-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="output" tabindex="0"><code>[...]
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
 [...]
-::::: (2024-10-11 14:29:07.548965) Unicorn spotted at moon!! Brightness: 100 iuhc</code></pre>
+::::: 2024-10-16 10:53:13.449393 Unicorn number 4 spotted at jupyter! Brightness: 100 iuhc</code></pre>
 </div>
-<p>Fantastic! We have now managed to share a file with the container,
-and have changed the behaviour of the container using this file.</p>
-<div class="section level3">
-<h3 id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a></h3>
-<p>We have learned about volumes and bind mounts, two ways to allow a
-container to access the host filesystem. We have used these to persist
-data between runs of a container and to share files with a
-container.</p>
-<p>They can both be a bit tricky to use, but are very useful tools for
-working with containers and have helped us get SPUC working much more
-like we want it to.</p>
+<p>Fantastic! We have now managed to share a file with the container.
+Not only that, but because we created the file before mounting it to the
+container, we are the owners, and can modify it. Changes to the file
+will reflect immediately on the container.</p>
+<p>For example, let’s edit the file to get rid of the date:</p>
+<div class="codewrapper sourceCode" id="cb29">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="bu">echo</span> <span class="st">"::::: Unicorn number {count} spotted at {location}! Brightness: {brightness} {units}"</span> <span class="op">&gt;</span> print.config</span></code></pre>
 </div>
+<p>Now let’s register a sighting, and look at the logs:</p>
+<div class="codewrapper sourceCode" id="cb30">
+<h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb30-1"><a href="#cb30-1" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=venus\&amp;brightness=148</span>
+<span id="cb30-2"><a href="#cb30-2" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
-<div class="section level2">
-<h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a></h2>
-<p>One other interesting reading from the SPUC README is the presence of
+<div class="codewrapper">
+<h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
+</h3>
+<pre class="output" tabindex="0"><code>{"message":"Unicorn sighting recorded!"}
+[...]
+::::: Unicorn number 7 spotted at venus! Brightness: 148 iuhc</code></pre>
+</div>
+<p>It almost seems too easy! We now have a print configuration and
+unicorn sighting record that persists between runs of the container.</p>
+<p><strong>Warning</strong>: We <em>replaced</em> the file in the
+container with the file from the host filesystem. We could do the same
+with a whole directory, but be careful not to overwrite important files
+in the container!</p>
+<div id="common-mistakes-with-volumes" class="callout challenge">
+<div class="callout-square">
+<i class="callout-icon" data-feather="zap"></i>
+</div>
+<div id="common-mistakes-with-volumes" class="callout-inner">
+<h3 class="callout-title">Common mistakes with volumes</h3>
+<div class="callout-content">
+<p>You have to be <em>really</em> careful with the syntax for volumes
+and mounts.</p>
+<p>Let’s imagine you are in a path containing a directory
+<code>spuc</code>, with an empty sub-directory <code>output</code> and a
+<code>print.config</code> file. What do you think will happen when you
+run the following commands?</p>
+<ol style="list-style-type: upper-alpha"><li><code>docker run -v spuc-vol spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spucs/output:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc-vol:/spuc/output spuacv/spuc:latest</code></li>
+<li><code>docker run -v ./spuc:/spuc spuacv/spuc:latest</code></li>
+<li><code>docker run -v print.config:/spuc/config/print.config spuacv/spuc:latest</code></li>
+</ol></div>
+</div>
+</div>
+<div id="accordionSolution1" class="accordion challenge-accordion accordion-flush">
+<div class="accordion-item">
+<button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
+  <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
+</button>
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div class="accordion-body">
+<ol style="list-style-type: upper-alpha"><li><p><strong>Problem:</strong> We provided a volume name, but not a
+path to mount it to. If the volume already existed, this will mount it
+on <code>/spuc-vol</code>. If the volume did not exist, it will create a
+directory <code>/spuc-vol</code> in the container, but it wont
+persist!<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Stop it and try again.</p></li>
+<li><p><strong>Problem:</strong> You misspelled the path! This will
+create a new directory called spuc<strong>s</strong> and mount it.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spucs</code> to remove the
+directory and try again.</p></li>
+<li><p><strong>Problem:</strong> At first, it seems like we will create
+a volume. However, we have provided a path, not a name for the volume.
+Therefore, Docker thinks you want a bind mount, and will create a (root
+owned) directory called <code>spuc-vol</code>.<br><strong>Fix:</strong> Use <code>sudo rm -rf ./spuc-volume</code> to
+remove the directory and try again.</p></li>
+<li><p><strong>Problem:</strong> This is valid syntax for a bind mount.
+It will take the almost empty <code>spuc</code> directory in your
+filesystem and mount it to <code>/spuc</code> in the container. However,
+it replaced everything in there in the process! Your command most likely
+failed because it could not find <code>/spuc/spuc.py</code>.<br><strong>Fix:</strong> You only messed up the container, nothing to worry
+about. Try again.</p></li>
+<li><p><strong>Problem:</strong> We forgot to use a path for the file!
+This will try to create a new volume called <code>print.config</code>
+and mount it to <code>/spuc/config/print.config</code>. However, it will
+most likely fail because <code>print.config</code> is not a
+directory.<br><strong>Fix:</strong> Use <code>docker volume rm print.config</code> to
+remove the volume and try again.</p></li>
+</ol></div>
+</div>
+</div>
+</div>
+</div>
+</section><section><h2 class="section-heading" id="setting-the-environment">Setting the environment<a class="anchor" aria-label="anchor" href="#setting-the-environment"></a></h2>
+<hr class="half-width"><p>One other interesting reading from the SPUC README is the presence of
 an environment variable, <code>EXPORT</code> which can be set to
 <code>True</code> to enable an API endpoint for exporting the unicorn
 sightings.</p>
@@ -694,12 +759,12 @@ <h2 id="setting-the-environment">Setting the environment<a class="anchor" aria-l
 <p>Thankfully this is quite straightforward, we can use the
 <code>-e</code> flag to set an environment variable in a container.</p>
 <p>Modifying our run command again:</p>
-<div class="codewrapper sourceCode" id="cb22">
+<div class="codewrapper sourceCode" id="cb32">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb22-1"><a href="#cb22-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb22-2"><a href="#cb22-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest</span>
-<span id="cb22-3"><a href="#cb22-3" tabindex="-1"></a><span class="ex">$</span> docker logs spuc_container</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb32-1"><a href="#cb32-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb32-2"><a href="#cb32-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest</span>
+<span id="cb32-3"><a href="#cb32-3" tabindex="-1"></a><span class="ex">docker</span> logs spuc_container</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -713,10 +778,10 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 ::::: Or 'curl localhost:8321/export' to download the unicorn sightings file!</code></pre>
 </div>
 <p>And now we can see that the export endpoint is available!</p>
-<div class="codewrapper sourceCode" id="cb24">
+<div class="codewrapper sourceCode" id="cb34">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb24-1"><a href="#cb24-1" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb34-1"><a href="#cb34-1" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -733,10 +798,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <p>Environment variables are a very common tool for configuring
 containers. They are used to set things like API keys, database
 connection strings, and other configuration options.</p>
-</div>
-<div class="section level2">
-<h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a></h2>
-<p>Finally, we must address a very serious shortcoming of the SPUC
+</section><section><h2 class="section-heading" id="passing-parameters">Passing parameters<a class="anchor" aria-label="anchor" href="#passing-parameters"></a></h2>
+<hr class="half-width"><p>Finally, we must address a very serious shortcoming of the SPUC
 container. It is recording the brightness of the unicorns in Imperial
 Unicorn Hoove Candles (iuhc)! This is a very outdated unit and we
 <strong>must</strong> change it to metric.</p>
@@ -744,13 +807,13 @@ <h2 id="passing-parameters">Passing parameters<a class="anchor" aria-label="anch
 the container to set the units to metric. This is done by passing a
 parameter to the container when it is run, overriding the default
 command.</p>
-<div class="codewrapper sourceCode" id="cb26">
+<div class="codewrapper sourceCode" id="cb36">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb26-1"><a href="#cb26-1" tabindex="-1"></a><span class="ex">$</span> docker stop spuc_container</span>
-<span id="cb26-2"><a href="#cb26-2" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> <span class="va">$PWD</span>/print.config:/code/config/print.config <span class="at">-v</span> spuc-volume:/code/output <span class="at">-e</span> EXPORT=true ghcr.io/uomresearchit/spuc:latest <span class="at">--units</span> iulu</span>
-<span id="cb26-3"><a href="#cb26-3" tabindex="-1"></a><span class="ex">$</span> curl <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
-<span id="cb26-4"><a href="#cb26-4" tabindex="-1"></a><span class="ex">$</span> curl localhost:8321/export/</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb36-1"><a href="#cb36-1" tabindex="-1"></a><span class="ex">docker</span> stop spuc_container</span>
+<span id="cb36-2"><a href="#cb36-2" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-d</span> <span class="at">--rm</span> <span class="at">--name</span> spuc_container <span class="at">-p</span> 8321:8321 <span class="at">-v</span> ./print.config:/spuc/config/print.config <span class="at">-v</span> spuc-volume:/spuc/output <span class="at">-e</span> EXPORT=true spuacv/spuc:latest <span class="at">--units</span> iulu</span>
+<span id="cb36-3"><a href="#cb36-3" tabindex="-1"></a><span class="ex">curl</span> <span class="at">-X</span> PUT localhost:8321/unicorn_spotted<span class="pp">?</span>location=earth\&amp;brightness=10</span>
+<span id="cb36-4"><a href="#cb36-4" tabindex="-1"></a><span class="ex">curl</span> localhost:8321/export/</span></code></pre>
 </div>
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -773,21 +836,21 @@ <h3 class="callout-title">Callout</h3>
 different command in the container, or if you want to run the container
 interactively.</p>
 <p>You may recall:</p>
-<div class="codewrapper sourceCode" id="cb28">
+<div class="codewrapper sourceCode" id="cb38">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb28-1"><a href="#cb28-1" tabindex="-1"></a><span class="ex">docker</span> inspect ghcr.io/uomresearchit/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
-<span id="cb28-2"><a href="#cb28-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /code/spuc.py] Command: [--units iuhc]</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb38-1"><a href="#cb38-1" tabindex="-1"></a><span class="ex">docker</span> inspect spuacv/spuc:latest <span class="at">-f</span> <span class="st">"Entrypoint: {{.Config.Entrypoint}} Command: {{.Config.Cmd}}"</span></span>
+<span id="cb38-2"><a href="#cb38-2" tabindex="-1"></a><span class="ex">Entrypoint:</span> [python /spuc/spuc.py] Command: [--units iuhc]</span></code></pre>
 </div>
-<p>That SPUC has an entrypoint of <code>python /code/spuc.py</code>
+<p>That SPUC has an entrypoint of <code>python /spuc/spuc.py</code>
 making it hard to interact with. We can override this using the
 <code>--entrypoint</code> flag.</p>
-<div class="codewrapper sourceCode" id="cb29">
+<div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
 </h3>
-<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb29-1"><a href="#cb29-1" tabindex="-1"></a><span class="ex">$</span> docker run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh ghcr.io/uomresearchit/spuc:latest</span></code></pre>
+<pre class="sourceCode bash" tabindex="0"><code class="sourceCode bash"><span id="cb39-1"><a href="#cb39-1" tabindex="-1"></a><span class="ex">docker</span> run <span class="at">-it</span> <span class="at">--rm</span> <span class="at">--entrypoint</span> /bin/sh spuacv/spuc:latest</span></code></pre>
 </div>
-<div id="discussion2" class="callout discussion">
+<div id="discussion1" class="callout discussion">
 <div class="callout-square">
 <i class="callout-icon" data-feather="message-circle"></i>
 </div>
@@ -800,17 +863,17 @@ <h3 class="callout-title">Challenge</h3>
 <th>Entrypoint</th>
 <th>Command</th>
 </tr></thead><tbody><tr class="odd"><td>A</td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 <td></td>
 </tr><tr class="even"><td>B</td>
-<td><code>python /code/spuc.py</code></td>
+<td><code>python /spuc/spuc.py</code></td>
 <td><code>--units iuhc</code></td>
 </tr><tr class="odd"><td>C</td>
 <td><code>python</code></td>
-<td><code>/code/spuc.py --units iuhc</code></td>
+<td><code>/spuc/spuc.py --units iuhc</code></td>
 </tr><tr class="even"><td>D</td>
 <td></td>
-<td><code>python /code/spuc.py --units iuhc</code></td>
+<td><code>python /spuc/spuc.py --units iuhc</code></td>
 </tr></tbody></table></div>
 </div>
 </div>
@@ -819,7 +882,7 @@ <h3 class="callout-title">Challenge</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>These are all valid combinations! The best choice depends on the use
 case.</p>
@@ -840,10 +903,8 @@ <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </div>
 </div>
 </div>
-</div>
-<div class="section level2">
-<h2 id="summary-1">Summary<a class="anchor" aria-label="anchor" href="#summary-1"></a></h2>
-<p>In this section, we have learned about volumes and bind mounts, two
+</section><section><h2 class="section-heading" id="summary">Summary<a class="anchor" aria-label="anchor" href="#summary"></a></h2>
+<hr class="half-width"><p>In this section, we have learned about volumes and bind mounts, two
 ways to allow a container to access the host filesystem. We have used
 these to persist data between runs of a container and to share files
 with a container.</p>
@@ -866,12 +927,7 @@ <h3 class="callout-title">Key Points</h3>
 </ul></div>
 </div>
 </div>
-</div>
-</div>
-
-
-
-      </div> <!-- / div.lesson-content -->
+</section></div> <!-- / div.lesson-content -->
     </main><!-- / main#main-content.main-content --><nav class="bottom-pagination mx-md-4" aria-label="Previous and Next Chapter"><div class="d-block d-sm-block d-md-none">
         <a class="chapter-link" href="../instructor/docker-cli-toolkit.html"><i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>Previous</a>
         <a class="chapter-link float-end" href="../instructor/docker-hub.html">Next<i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i></a>
@@ -924,13 +980,13 @@ <h3 class="callout-title">Key Points</h3>
   "dct:conformsTo": "https://bioschemas.org/profiles/TrainingMaterial/1.0-RELEASE",
   "description": "A Carpentries Lesson teaching foundational data and coding skills to researchers worldwide",
   "keywords": "software, data, lesson, The Carpentries",
-  "name": "Using the full power of the Docker CLI",
+  "name": "Sharing information with containers",
   "creativeWorkStatus": "active",
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/docker-cli-advanced.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/docker-cli-advanced.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/docker-cli-toolkit.html b/instructor/docker-cli-toolkit.html
index 40af1b5..c7e5b10 100644
--- a/instructor/docker-cli-toolkit.html
+++ b/instructor/docker-cli-toolkit.html
@@ -253,7 +253,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -337,13 +337,13 @@ <h2 class="accordion-header" id="flush-headingTwelve">
           Previous: Docker Desktop
         </a>
         <a class="chapter-link float-end" href="../instructor/docker-cli-advanced.html" rel="next">
-          Next: Using the full power...
+          Next: Sharing information...
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i>
         </a>
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Building our Docker CLI toolkit</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-cli-toolkit.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -872,7 +872,7 @@ <h3 class="accordion-header" id="headingSpoiler1">
   Logs
   </h3>
 </button>
-<div id="collapseSpoiler1" class="accordion-collapse collapse" data-bs-parent="#accordionSpoiler1" aria-labelledby="headingSpoiler1">
+<div id="collapseSpoiler1" class="accordion-collapse collapse" aria-labelledby="headingSpoiler1" data-bs-parent="#accordionSpoiler1">
 <div class="accordion-body">
 <div class="codewrapper">
 <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1263,7 +1263,7 @@ <h3 class="callout-title">Key Points</h3>
           Previous: Docker Desktop
         </a>
         <a class="chapter-link float-end" href="../instructor/docker-cli-advanced.html" rel="next">
-          Next: Using the full power...
+          Next: Sharing information...
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-right"></i>
         </a>
       </div>
@@ -1309,8 +1309,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/docker-cli-toolkit.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/docker-cli-toolkit.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/docker-compose.html b/instructor/docker-compose.html
index 5949243..fa35b19 100644
--- a/instructor/docker-compose.html
+++ b/instructor/docker-compose.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -340,7 +340,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Using Docker Compose</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-compose.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -1190,8 +1190,8 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/docker-compose.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/docker-compose.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/docker-desktop.html b/instructor/docker-desktop.html
index 10a0a85..cd5bf5c 100644
--- a/instructor/docker-desktop.html
+++ b/instructor/docker-desktop.html
@@ -250,7 +250,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -340,7 +340,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Docker Desktop</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-desktop.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -503,17 +503,17 @@ <h3 class="tab-header" id="nav-tab-heading-1-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-1" class="tab-content">
-<div id="nav-tabpanel-1-Logs" class="tab-pane show active" aria-labelledby="nav-tab-1-Logs" role="tabpanel">
+<div id="nav-tabpanel-1-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-1-Logs">
 <figure><img src="../fig/docker-desktop/hello_log.png" alt="Logs tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Inspect" class="tab-pane" aria-labelledby="nav-tab-1-Inspect" role="tabpanel">
+<div id="nav-tabpanel-1-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Inspect">
 <figure><img src="../fig/docker-desktop/hello_inspect.png" alt="Inspect tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-1-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-1-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Bindmounts">
 <figure><img src="../fig/docker-desktop/hello_bind.png" alt="Bind mounts tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Exec" class="tab-pane" aria-labelledby="nav-tab-1-Exec" role="tabpanel">
+<div id="nav-tabpanel-1-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Exec">
 <figure><img src="../fig/docker-desktop/hello_exec.png" alt="Exec tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Files" class="tab-pane" aria-labelledby="nav-tab-1-Files" role="tabpanel">
+<div id="nav-tabpanel-1-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Files">
 <figure><img src="../fig/docker-desktop/hello_files.png" alt="Files tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-1-Stats" class="tab-pane" aria-labelledby="nav-tab-1-Stats" role="tabpanel">
+<div id="nav-tabpanel-1-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-1-Stats">
 <figure><img src="../fig/docker-desktop/hello_stats.png" alt="Stats tab in container from hello-world image." class="figure mx-auto d-block"></figure></div>
 </div>
 </div>
@@ -592,17 +592,17 @@ <h3 class="tab-header" id="nav-tab-heading-2-Stats">
 </button>
 </div>
 </nav><div id="nav-tabContent-2" class="tab-content">
-<div id="nav-tabpanel-2-Logs" class="tab-pane show active" aria-labelledby="nav-tab-2-Logs" role="tabpanel">
+<div id="nav-tabpanel-2-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-2-Logs">
 <figure><img src="../fig/docker-desktop/spuc_log.png" alt="Logs tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Inspect" class="tab-pane" aria-labelledby="nav-tab-2-Inspect" role="tabpanel">
+<div id="nav-tabpanel-2-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Inspect">
 <figure><img src="../fig/docker-desktop/spuc_inspect.png" alt="Inspect tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-2-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-2-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Bindmounts">
 <figure><img src="../fig/docker-desktop/spuc_bind.png" alt="Bind mounts tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Exec" class="tab-pane" aria-labelledby="nav-tab-2-Exec" role="tabpanel">
+<div id="nav-tabpanel-2-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Exec">
 <figure><img src="../fig/docker-desktop/spuc_exec.png" alt="Exec tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Files" class="tab-pane" aria-labelledby="nav-tab-2-Files" role="tabpanel">
+<div id="nav-tabpanel-2-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Files">
 <figure><img src="../fig/docker-desktop/spuc_files.png" alt="Files tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-2-Stats" class="tab-pane" aria-labelledby="nav-tab-2-Stats" role="tabpanel">
+<div id="nav-tabpanel-2-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-2-Stats">
 <figure><img src="../fig/docker-desktop/spuc_stats.png" alt="Stats tab in container from spuc image." class="figure mx-auto d-block"></figure></div>
 </div>
 </div>
@@ -773,17 +773,17 @@ <h3 class="tab-header" id="nav-tab-heading-3-Stats">
 </button>
 </div>
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-<div id="nav-tabpanel-3-Logs" class="tab-pane show active" aria-labelledby="nav-tab-3-Logs" role="tabpanel">
+<div id="nav-tabpanel-3-Logs" class="tab-pane show active" role="tabpanel" aria-labelledby="nav-tab-3-Logs">
 <figure><img src="../fig/docker-desktop/alpine_logs.png" alt="Logs tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Inspect" class="tab-pane" aria-labelledby="nav-tab-3-Inspect" role="tabpanel">
+<div id="nav-tabpanel-3-Inspect" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Inspect">
 <figure><img src="../fig/docker-desktop/alpine_inspect.png" alt="Inspect tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" aria-labelledby="nav-tab-3-Bindmounts" role="tabpanel">
+<div id="nav-tabpanel-3-Bindmounts" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Bindmounts">
 <figure><img src="../fig/docker-desktop/alpine_bind.png" alt="Bind mounts tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Exec" class="tab-pane" aria-labelledby="nav-tab-3-Exec" role="tabpanel">
+<div id="nav-tabpanel-3-Exec" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Exec">
 <figure><img src="../fig/docker-desktop/alpine_exec.png" alt="Exec tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Files" class="tab-pane" aria-labelledby="nav-tab-3-Files" role="tabpanel">
+<div id="nav-tabpanel-3-Files" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Files">
 <figure><img src="../fig/docker-desktop/alpine_files.png" alt="Files tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
-<div id="nav-tabpanel-3-Stats" class="tab-pane" aria-labelledby="nav-tab-3-Stats" role="tabpanel">
+<div id="nav-tabpanel-3-Stats" class="tab-pane" role="tabpanel" aria-labelledby="nav-tab-3-Stats">
 <figure><img src="../fig/docker-desktop/alpine_stats.png" alt="Stats tab in container from alpine image." class="figure mx-auto d-block"></figure></div>
 </div>
 </div>
@@ -882,8 +882,8 @@ <h3 class="callout-title">Key Points</h3>
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   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/docker-hub.html b/instructor/docker-hub.html
index 67073bd..59d3614 100644
--- a/instructor/docker-hub.html
+++ b/instructor/docker-hub.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -328,7 +328,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
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         <a class="chapter-link" href="../instructor/docker-cli-advanced.html" rel="prev">
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>
-          Previous: Using the full power
+          Previous: Sharing information
         </a>
         <a class="chapter-link float-end" href="../instructor/creating-container-images.html" rel="next">
           Next: Creating Your Own...
@@ -337,7 +337,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>The Docker Hub</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/docker-hub.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -584,7 +584,7 @@ <h3 class="callout-title">Key Points</h3>
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         <a class="chapter-link" href="../instructor/docker-cli-advanced.html" rel="prev">
           <i aria-hidden="true" class="small-arrow" data-feather="arrow-left"></i>
-          Previous: Using the full power
+          Previous: Sharing information
         </a>
         <a class="chapter-link float-end" href="../instructor/creating-container-images.html" rel="next">
           Next: Creating Your Own...
@@ -633,8 +633,8 @@ <h3 class="callout-title">Key Points</h3>
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-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/images.html b/instructor/images.html
index bb01f2b..ebcd3da 100644
--- a/instructor/images.html
+++ b/instructor/images.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -519,7 +519,7 @@ <h3 id="docker-desktop-figure-40">Figure 40</h3>
 <hr class="half-width">
 <h3 id="docker-cli-toolkit-figure-1">Figure 1</h3>
 <p aria-hidden="true">Image 1 of 1: ‘A diagram showing the syntactic structure of a Docker command’</p>
-<figure><img src="../fig/docker_cmd.png" alt="A diagram showing the syntactic structure of a Docker command" class="figure mx-auto d-block"></figure><hr></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Using the full power of the Docker CLIData in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></a></h2>
+<figure><img src="../fig/docker_cmd.png" alt="A diagram showing the syntactic structure of a Docker command" class="figure mx-auto d-block"></figure><hr></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Sharing information with containers</a></h2>
 <hr class="half-width"></section><section id="docker-hub"><h2 class="section-heading"><a href="docker-hub.html">The Docker Hub</a></h2>
 <hr class="half-width">
 <h3 id="docker-hub-figure-1">Figure 1</h3>
@@ -592,8 +592,8 @@ <h3 id="docker-hub-figure-7">Figure 7</h3>
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-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/index.html b/instructor/index.html
index 17d9fe8..b8c2e2d 100644
--- a/instructor/index.html
+++ b/instructor/index.html
@@ -236,7 +236,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -430,12 +430,11 @@ <h3 class="callout-title">A note about Docker</h3>
 <span class="visually-hidden">Duration: </span>03h 58m
 </td>
 <td>
- 4. <a href="docker-cli-advanced.html">Using the full power of the
-Docker CLI</a>
+ 4. <a href="docker-cli-advanced.html">Sharing information with
+containers</a>
 </td>
 <td>
-What actually happens when I run a container?<br>How can I control the
-behaviour of containers?<br>How do I get data in and out of
+How do I get information in and out of
 containers?<br>::::::::::::::::::::::::::::::::::::::::::::::::::
 </td>
 </tr><tr><td>
@@ -537,7 +536,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Windows
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Installation of Docker on Microsoft Windows comprises two central
 steps:</p>
@@ -627,7 +626,7 @@ <h4 class="accordion-header" id="headingSolution2">
   Mac
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>Please install docker following these <a href="https://docs.docker.com/desktop/install/mac-install/" class="external-link">instructions</a>.</p>
 </div>
@@ -641,7 +640,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Linux
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Installation on Linux requires two steps:</p>
 <ul><li>Installation of Docker Engine</li>
@@ -787,8 +786,8 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
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-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/instructor-notes.html b/instructor/instructor-notes.html
index 53145eb..491a658 100644
--- a/instructor/instructor-notes.html
+++ b/instructor/instructor-notes.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -388,7 +388,7 @@ <h1>Instructor Notes</h1>
 </section><section id="aggregate-instructor-notes"><section id="introduction"><h2 class="section-heading"><a href="introduction.html">Introducing Containers</a></h2>
 <hr class="half-width"></section><section id="docker-desktop"><h2 class="section-heading"><a href="docker-desktop.html">Docker Desktop</a></h2>
 <hr class="half-width"></section><section id="docker-cli-toolkit"><h2 class="section-heading"><a href="docker-cli-toolkit.html">Building our Docker CLI toolkit</a></h2>
-<hr class="half-width"></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Using the full power of the Docker CLIData in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></a></h2>
+<hr class="half-width"></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Sharing information with containers</a></h2>
 <hr class="half-width"></section><section id="docker-hub"><h2 class="section-heading"><a href="docker-hub.html">The Docker Hub</a></h2>
 <hr class="half-width"></section><section id="creating-container-images"><h2 class="section-heading"><a href="creating-container-images.html">Creating Your Own Container Images</a></h2>
 <hr class="half-width"></section><section id="docker-compose"><h2 class="section-heading"><a href="docker-compose.html">Using Docker Compose</a></h2>
@@ -440,8 +440,8 @@ <h1>Instructor Notes</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/instructor-notes.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/instructor-notes.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/introduction.html b/instructor/introduction.html
index 05e914c..d3b1b2e 100644
--- a/instructor/introduction.html
+++ b/instructor/introduction.html
@@ -245,7 +245,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -335,7 +335,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Introducing Containers</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/introduction.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -670,8 +670,8 @@ <h3 class="callout-title">Key Points</h3>
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   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
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 }
 
   </script><script>
diff --git a/instructor/key-points.html b/instructor/key-points.html
index fbc80bd..5a46ad7 100644
--- a/instructor/key-points.html
+++ b/instructor/key-points.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -556,7 +556,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
 <td>Remove the container when it is stopped</td>
 </tr>
 </tbody>
-</table></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Using the full power of the Docker CLIData in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></a></h2>
+</table></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Sharing information with containers</a></h2>
 <hr class="half-width">
 <ul>
 <li>Volumes and bind mounts are two ways to allow a container to access
@@ -650,8 +650,8 @@ <h2 class="accordion-header" id="flush-headingTwelve">
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   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/key-points.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/instructor/profiles.html b/instructor/profiles.html
index b21729b..785add9 100644
--- a/instructor/profiles.html
+++ b/instructor/profiles.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -353,8 +353,8 @@ <h1>Learner Profiles</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/instructor/profiles.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/instructor/profiles.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>
diff --git a/introduction.html b/introduction.html
index c639923..7656799 100644
--- a/introduction.html
+++ b/introduction.html
@@ -245,7 +245,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -336,7 +336,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Introducing Containers</h1>
-        <p>Last updated on 2024-10-15 |
+        <p>Last updated on 2024-10-16 |
 
         <a href="https://github.com/UoMResearchIT/docker-introduction/edit/main/episodes/introduction.Rmd" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -669,8 +669,8 @@ <h3 class="callout-title">Key Points</h3>
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   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
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 }
 
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diff --git a/key-points.html b/key-points.html
index 3ec004a..341db10 100644
--- a/key-points.html
+++ b/key-points.html
@@ -277,7 +277,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div>
 <!--/div.accordion-header-->
 
@@ -556,7 +556,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
 <td>Remove the container when it is stopped</td>
 </tr>
 </tbody>
-</table></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Using the full power of the Docker CLIData in containers<a class="anchor" aria-label="anchor" href="#data-in-containers"></a></a></h2>
+</table></section><section id="docker-cli-advanced"><h2 class="section-heading"><a href="docker-cli-advanced.html">Sharing information with containers</a></h2>
 <hr class="half-width">
 <ul>
 <li>Volumes and bind mounts are two ways to allow a container to access
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-  "dateModified": "2024-10-15",
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+  "dateModified": "2024-10-16",
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diff --git a/md5sum.txt b/md5sum.txt
index d042bca..c9d3c65 100644
--- a/md5sum.txt
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diff --git a/pkgdown.yml b/pkgdown.yml
index 81ffd60..6742b87 100644
--- a/pkgdown.yml
+++ b/pkgdown.yml
@@ -2,4 +2,4 @@ pandoc: 3.1.11
 pkgdown: 2.1.1
 pkgdown_sha: ~
 articles: {}
-last_built: 2024-10-15T20:17Z
+last_built: 2024-10-16T15:09Z
diff --git a/profiles.html b/profiles.html
index 787eee8..a6be7b5 100644
--- a/profiles.html
+++ b/profiles.html
@@ -232,7 +232,7 @@ <h2 class="accordion-header chapters" id="flush-headingEleven">
 <div class="accordion accordion-flush" id="accordionFlush5">
   <div class="accordion-item">
     <div class="accordion-header" id="flush-heading5">
-        <a href="docker-cli-advanced.html">4. Using the full power of the Docker CLI</a>
+        <a href="docker-cli-advanced.html">4. Sharing information with containers</a>
     </div><!--/div.accordion-header-->
 
   </div><!--/div.accordion-item-->
@@ -354,8 +354,8 @@ <h1>Learner Profiles</h1>
   "url": "https://uomresearchit.github.io/docker-introduction/profiles.html",
   "identifier": "https://uomresearchit.github.io/docker-introduction/profiles.html",
   "dateCreated": "2015-04-18",
-  "dateModified": "2024-10-15",
-  "datePublished": "2024-10-15"
+  "dateModified": "2024-10-16",
+  "datePublished": "2024-10-16"
 }
 
   </script><script>