Deny App CR update status.reconciledAt

kyverno-mutate-policy.yaml

apiVersion: kyverno.io/v1
kind: Policy
metadata:
  name: drop-reconciledat-only-update
  namespace: your-namespace  # Replace with your target namespace
spec:
  mutateExistingOnPolicyUpdate: false  # Only mutate admission requests, not existing resources
  rules:
    - name: drop-reconciledat-only-update
      match:
        any:
          - resources:
              kinds:
                - Application  # Targeting the Application CR
              operations:
                - UPDATE  # Only checking UPDATE operations
      mutate:
        patchesJson6902: |
          - op: remove
            path: "/status/reconciledAt"

kyverno-validate-policy.yaml

apiVersion: kyverno.io/v1
kind: Policy
metadata:
  name: deny-application-only-update-status-reconciledat
  namespace: argocd
spec:
  validationFailureAction: Enforce
  background: false
  rules:
    - name: deny-application-only-update-status-reconciledat
      match:
        any:
          - resources:
              kinds:
                - Application
              operations:
                - UPDATE
      validate:
        message: "Updating Application is denied unless only status.reconciledAt changes."
        deny:
          conditions:
            all:
              # Condition 1: status.reconciledAt has changed
              - key: "{{ request.object.status.reconciledAt || '' }}"
                operator: "NotEquals"
                value: "{{ request.oldObject.status.reconciledAt || '' }}"
              
              # Condition 2: All other fields in request.object.status remain the same
              - key: "{{ request.object }}"
                operator: "NotEquals"
                value: "{{ request.oldObject }}"