kyverno/test/policy/validate/check_registries.yaml

---
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: check-registries
spec:
  admission: true
  background: true
  rules:
  - match:
      any:
      - resources:
          kinds:
          - Deployment
          - StatefulSet
    name: check-registries
    validate:
      message: Registry is not allowed
      pattern:
        spec:
          template:
            spec:
              containers:
              - image: '*/nirmata/* | https://private.registry.io/*'
                name: '*'
  validationFailureAction: Audit