Enforce etcd encryption in OpenShift in CEL expressions

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: enforce-etcd-encryption
  annotations:
    policies.kyverno.io/title: Enforce etcd encryption in OpenShift in CEL expressions
    policies.kyverno.io/category: OpenShift
    policies.kyverno.io/severity: high
    kyverno.io/kyverno-version: 1.11.0
    policies.kyverno.io/minversion: 1.11.0
    kyverno.io/kubernetes-version: 1.26-1.27
    policies.kyverno.io/subject: APIServer
    policies.kyverno.io/description: Encryption at rest is a security best practice. This policy ensures encryption is enabled for etcd in OpenShift clusters.
spec:
  validationFailureAction: Enforce
  background: true
  rules:
    - name: check-etcd-encryption
      match:
        any:
          - resources:
              kinds:
                - config.openshift.io/v1/APIServer
              operations:
                - CREATE
                - UPDATE
      validate:
        cel:
          expressions:
            - expression: has(object.spec.encryption)
              message: Encryption should be enabled for etcd