libvirt: new setting deployment.libvirtd.template

Allows for maximum flexibility in the definition of the libvirt domain. Also considers the possibility of domain creation failing
NixOS · Apr 6, 2018 · 5a50093 · 5a50093
1 parent da33620
commit 5a50093
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Showing 2 changed files with 42 additions and 32 deletions.
diff --git a/nix/libvirtd.nix b/nix/libvirtd.nix
@@ -53,6 +53,32 @@ in
       '';
     };
 
+    deployment.libvirtd.template = mkOption {
+      type = types.str;
+      default = ''<domain type="{domain_type}">
+          <name>{name}</name>
+          <memory unit="MiB">{memory_size}</memory>
+          <vcpu>{vcpu}</vcpu>
+          {os}
+          <devices>
+              <emulator>{emulator}</emulator>
+            <disk type="file" device="disk">
+              <driver name="qemu" type="qcow2"/>
+              <source file="{diskPath}"/>
+              <target dev="hda"/>
+            </disk>
+            {interfaces}
+            <input type="keyboard" bus="usb"/>
+            <input type="mouse" bus="usb"/>
+            {extra_devices}
+          </devices>
+          {extra_domain}
+        </domain>'';
+      description = ''
+        Template for the libvirt domain. You can use all other parameters.
+      '';
+    };
+
     deployment.libvirtd.vcpu = mkOption {
       default = 1;
       type = types.int;

diff --git a/nixops/backends/libvirtd.py b/nixops/backends/libvirtd.py
@@ -29,6 +29,7 @@ def __init__(self, xml, config):
 
         x = xml.find("attrs/attr[@name='libvirtd']/attrs")
         assert x is not None
+        self.domain_tpl = x.find("attr[@name='template']/string").get("value")
         self.vcpu = x.find("attr[@name='vcpu']/int").get("value")
         self.memory_size = x.find("attr[@name='memorySize']/int").get("value")
         self.extra_devices = x.find("attr[@name='extraDevicesXML']/string").get("value")
@@ -185,38 +186,19 @@ def _make_os(defn):
                 "    <cmdline>%s</cmdline>"% defn.cmdline if len(defn.kernel) > 0 else "",
                 '</os>']
 
-
-        domain_fmt = "\n".join([
-            '<domain type="{5}">',
-            '  <name>{0}</name>',
-            '  <memory unit="MiB">{1}</memory>',
-            '  <vcpu>{4}</vcpu>',
-            '\n'.join(_make_os(defn)),
-            '  <devices>',
-            '    <emulator>{2}</emulator>',
-            '    <disk type="file" device="disk">',
-            '      <driver name="qemu" type="qcow2"/>',
-            '      <source file="{3}"/>',
-            '      <target dev="hda"/>',
-            '    </disk>',
-            '\n'.join([iface(n) for n in defn.networks]),
-            '    <graphics type="vnc" port="-1" autoport="yes"/>' if not defn.headless else "",
-            '    <input type="keyboard" bus="usb"/>',
-            '    <input type="mouse" bus="usb"/>',
-            defn.extra_devices,
-            '  </devices>',
-            defn.extra_domain,
-            '</domain>',
-        ])
-
-        return domain_fmt.format(
-            self._vm_id(),
-            defn.memory_size,
-            qemu,
-            self._disk_path(defn),
-            defn.vcpu,
-            defn.domain_type
+        result = defn.domain_tpl.format(
+            name=self._vm_id(),
+            memory_size=defn.memory_size,
+            os='\n'.join(_make_os(defn)),
+            emulator=qemu,
+            interfaces='\n'.join([iface(n) for n in defn.networks]),
+            diskPath=self._disk_path(defn),
+            vcpu=defn.vcpu,
+            domain_type=defn.domain_type,
+            extra_domain=defn.extra_domain,
+            extra_devices=defn.extra_devices + ('<graphics type="vnc" port="-1" autoport="yes"/>' if not defn.headless else ""),
         )
+        return result
 
     def _parse_ip(self):
         """
@@ -260,7 +242,9 @@ def start(self):
             self.private_ipv4 = self._parse_ip()
         else:
             self.log("starting...")
-            self.dom.create()
+            if self.dom.create() is False:
+                self.log("Failed to create domain ");
+                return False
             self._wait_for_ip(0)
 
     def get_ssh_name(self):