kyverno/test/more/add_default_labels.yaml

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: add-default-labels
spec:
  background: false
  rules:
  - name: add-default-labels
    match:
      resources:
        kinds:
        - Pod
        - Service
        - Namespace
    mutate:
      patchStrategicMerge:
        metadata:
          labels:
            custom-foo-label: my-bar-default