drain-cleaner not invoked when nodes are drained.

[raj-saxena]

We installed drain-cleaner recently to smoothen the process of upgrading node-pools using the helm-chart.

We are using GKE and our cluster has cert-manager so we went with default configuration and the only values that we had to change were:

namespace:
  create: false
  name: strimzi

I have verified that there is a ValidatingWebhookConfiguration -

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
  annotations:
    cert-manager.io/inject-ca-from: strimzi/strimzi-drain-cleaner
    meta.helm.sh/release-name: strimzi-drain-cleaner
    meta.helm.sh/release-namespace: strimzi
  creationTimestamp: "2023-06-09T06:16:44Z"
  generation: 4
  labels:
    app: strimzi-drain-cleaner
    app.kubernetes.io/instance: strimzi-drain-cleaner
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: strimzi-drain-cleaner
    app.kubernetes.io/version: 0.4.2
    helm.sh/chart: strimzi-drain-cleaner-0.4.2
  name: strimzi-drain-cleaner
  resourceVersion: "829436629"
  uid: efe30ac2-ad9c-4d32-bfff-8f2b10ec1f2a
webhooks:
- admissionReviewVersions:
  - v1
  clientConfig:
    caBundle: LS0t....0tLQo=
    service:
      name: strimzi-drain-cleaner
      namespace: strimzi
      path: /drainer
      port: 443
  failurePolicy: Ignore
  matchPolicy: Equivalent
  name: strimzi-drain-cleaner.strimzi.io
  namespaceSelector: {}
  objectSelector: {}
  rules:
  - apiGroups:
    - ""
    apiVersions:
    - v1
    operations:
    - CREATE
    resources:
    - pods/eviction
    scope: Namespaced
  sideEffects: None
  timeoutSeconds: 5

However, we drain the nodes, we don't see any logs as this blog says

Any suggestions to investigate?