Webhook Conversion Demo - "Multiverse Operator"

Summary

This operator manages a sample custom resource MyCustomKind for demonstrating webhook conversion. The reconciliation logic is not implemented as it is out of scope.

Walkthrough

At the time of publication, the controller-manager image exists on Quay.io. This means that you can just run the following command from the repo root to install the controller-manager in your cluster. This does require Cert-Manager be installed already to automatically manager certificates needed by your webhook.

make deploy
oc project multiverse-operator-system

From there, you can install either sample in the config/samples/ directory.

oc apply -f config/samples/demo_v1beta1_mycustomkind.yaml

With the instance installed, you should then be able to see the conversion in play:

oc get mycustomkind.v1alpha1.demo.example.com mycustomkind-v1beta1-sample -o yaml

In this particular example, you would see that the bar key with value baz is represented in the annotations because it does not exists in the spec of the v1alpha1 representation of MyCustomKind

apiVersion: demo.example.com/v1alpha1
kind: MyCustomKind
metadata:
  annotations:
    conversion.mycustomkind.demo.example.com/bar: baz
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"demo.example.com/v1beta1","kind":"MyCustomKind","metadata":{"annotations":{},"name":"mycustomkind-v1beta1-sample","namespace":"multiverse-operator-system"},"spec":{"bar":"baz","newFoo":"teehee"}}
  creationTimestamp: "2021-04-15T22:22:09Z"
  generation: 1
  managedFields:
    # omitted
  name: mycustomkind-v1beta1-sample
  namespace: multiverse-operator-system
  resourceVersion: "107033543"
  selfLink: /apis/demo.example.com/v1alpha1/namespaces/multiverse-operator-system/mycustomkinds/mycustomkind-v1beta1-sample
  uid: e19b3d2e-5d95-474d-ab7b-36a8c282134c
spec:
  foo: teehee
status: {}

Conversely, the v1alpha1 representation of MyCustomKind accepts a key zap with an int32 value. You can edit the existing resource and add .spec.zap=3, after which you should see the value persisted to annotations in the v1beta1 representation of the instance.

Cleanup

Just run:

make undeploy