kyverno/test/Deployment/policy-deployment-any.yaml

apiVersion : kubepolicy.nirmata.io/v1alpha1
kind : Policy
metadata :
  name : policy-deployment
spec :
  rules:
    - name: "First policy v2"
      resource:
        kinds : 
        - Deployment
      mutate:
        patches:
        - path: /metadata/labels/isMutated
          op: add
          value: "true"
        - path: /metadata/labels/app
          op: replace
          value: "nginx_is_mutated"

      validate:
        message: "Because I like only mutated resources"
        pattern:
          metadata:
            labels:
              app: "*mutated"