Install the operator

Install the resource definition and the operator from the kustomize base in the operator’s deploy/ directory. You need kubectl with cluster-admin rights. The base puts the operator in the liken-system namespace.

Add the base to your own kustomization and pin <ref> to a release tag. A pinned ref installs the same definition and the same operator image every time you apply it.

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
  - https://github.com/liken-sh/liken//people-operator/deploy?ref=<ref>

The base holds five parts:

• the Person resource definition, which is cluster-scoped;
• the people-operator ServiceAccount and its ClusterRole, which reads every Person, writes each Person’s status, and starts, reads, and deletes the pods that read a picture from NFS or a claim;
• a Role in default, which posts the Events about each Person;
• a Role in liken-system, which creates, reads, and renews the Lease named people-operator;
• the people-operator Deployment, with one replica.

Only one copy of the operator acts at a time. Each copy competes for the Lease named people-operator in liken-system, and only the copy that holds it watches, writes statuses, and starts the pods that read a picture. Two copies that acted at once would race on the same pod that read a picture, and one of them would mark a picture that baked as failed.

A rollout starts the new pod beside the old one. The old pod finishes the Person it is answering, writes the Events it posted, and releases the Lease when it stops, and the new pod takes it within about 11 seconds. When an Event write does not return within 5 seconds, the old pod exits without the release, and the new pod takes the Lease when it expires. A leader that can’t renew the Lease, such as one on a node the control plane can’t reach, stops writing 10 seconds after its last renewal and then exits. A waiting copy takes a Lease that nobody renews 30 to 41 seconds after its last renewal. kubectl -n liken-system get lease people-operator shows the pod that leads.

Watch the operator start:

kubectl -n liken-system rollout status deployment/people-operator

Declare the people

The object’s name is the name every other resource uses to refer to this person, so choose it once. A change to it later breaks every reference. displayName is what a screen shows, and nickname is a one-word form of it.

apiVersion: people.liken.sh/v1alpha1
kind: Person
metadata:
  name: ada
spec:
  displayName: Ada Lovelace
  nickname: Ada

kubectl get people lists them. Within a few seconds, the Picture column shows Initials: the operator drew the person’s initials into status.thumbnail. The pictures guide shows how to give a person a picture in place of the initials.

Run a development build

Every push to main publishes a development build of the image. Pin the base to the commit and the image to the build’s tag with an images entry in your kustomization:

images:
  - name: ghcr.io/liken-sh/people-operator
    newTag: <tag>

The operator reads its own image from its pod, and each pod that reads a picture runs the same image, so the one entry sets both.

Remove the operator

Delete the Deployment to stop the operator. Each Person keeps its status, and the screens keep the pictures in it. A picture that changes after that does not reach the screens.

kubectl -n liken-system delete deployment/people-operator

Delete the base to remove the definition too. That deletes every Person, and with them every Play that names one as its owner.

The operator creates its Lease itself, so the base does not hold it, and it stays after you delete the base. Delete it with kubectl -n liken-system delete lease people-operator.