feat: add-example-custom-crd and update readme.md

README.md

@@ -1,9 +1,51 @@
-# template-operator
+# Template Operator
 
+<!-- markdownlint-disable-next-line MD036 -->
+**Simple, reconciliation-based runtime templating**
 
+The Template Operator is for platform engineers needing an easy and reliable way to create, copy and update kubernetes resources.
 
+## Design principles
 
-An example replicating the functionality of https://github.com/pusher/quack
+- **100% YAML** – `Templates` are valid YAML and IDE validation and autocomplete of k8s resources works as normal.
+- **Simple** – Easy to use and quick to get started.
+- **Reconciliation based** – Changes are applied quickly and resiliently (unlike webhooks) at runtime.
+
+### Alternatives
+
+There are alternative templating systems in use by the k8s community – each has valid use cases and noting the downsides for runtime templating is not intended as an indictment – all are excellent choices under the right conditions.
+
+| Alternative              | Downside for templating                                  |
+| ------------------------ | :------------------------------------------------------- |
+| [crossplane][crossplane] | Complex due to design for infrastructure composition     |
+| [kyverno][kyverno]       | Webhook based<br />Designed as a policy engine           |
+| [helm][helm]             | Not 100% YAML<br />Not reconciliation based (build time) |
+
+[crossplane]: https://crossplane.io/  "Crossplane"
+[kyverno]: https://kyverno.io/  "Kyverno"
+[helm]: https://helm.sh/ "Helm"
+
+## Installation
+
+API documentation available [here](https://pkg.go.dev/github.com/flanksource/template-operator/api/v1).
+
+### Prerequisites
+
+This guide assumes you have either a [kind cluster](https://kind.sigs.k8s.io/docs/user/quick-start/) or [minikube cluster](https://minikube.sigs.k8s.io/docs/start/) running, or have some other way of interacting with a cluster via [kubectl](https://kubernetes.io/docs/tasks/tools/).
+
+### Install
+
+```bash
+export VERSION=0.2.0
+# For the latest release version: https://github.com/flanksource/template-operator/releases
+
+# Apply the operator
+kubectl apply -f https://github.com/flanksource/template-operator/releases/download/v${VERSION}/operator.yml
+```
+
+## Other examples
+
+An example replicating the functionality of <https://github.com/pusher/quack>
 
 ```yaml
 apiVersion: templating.flanksource.com/v1
@@ -27,7 +69,8 @@ spec:
                 -  "{{.source.spec.rules[0].host}}.{{-   kget "cm/quack/quack-config" "data.domain" }}"
 ```
 
-An example replicating  https://github.com/redhat-cop/namespace-configuration-operator
+An example replicating  <https://github.com/redhat-cop/namespace-configuration-operator>
+
 ```yaml
 apiVersion: templating.flanksource.com/v1
 kind: Template

examples/tutorial-crd.yaml

@@ -0,0 +1,59 @@
+# This file is for use by blogposts and examples
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.4.1
+  creationTimestamp: null
+  name: tutorialservices.tutorial.tutorial
+spec:
+  group: tutorial.tutorial
+  names:
+    kind: TutorialService
+    listKind: TutorialServiceList
+    plural: tutorialservices
+    singular: tutorialservice
+  scope: Namespaced
+  versions:
+  - name: v1
+    schema:
+      openAPIV3Schema:
+        description: TutorialService is the Schema for the tutorialservices API
+        properties:
+          apiVersion:
+            description: 'APIVersion defines the versioned schema of this representation
+              of an object. Servers should convert recognized schemas to the latest
+              internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+            type: string
+          kind:
+            description: 'Kind is a string value representing the REST resource this
+              object represents. Servers may infer this from the endpoint the client
+              submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: TutorialServiceSpec defines the desired state of TutorialService
+            properties:
+              domain:
+                type: string
+              image:
+                type: string
+              replicas:
+                type: integer
+            required:
+            - domain
+            - image
+            type: object
+        type: object
+    served: true
+    storage: true
+    subresources:
+      status: {}
+status:
+  acceptedNames:
+    kind: ""
+    plural: ""
+  conditions: []
+  storedVersions: []