---
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: mutate-emptydir
spec:
  admission: true
  background: true
  rules:
  - match:
      any:
      - resources:
          kinds:
          - Deployment
    mutate:
      foreach:
      - list: request.object.spec.template.spec.volumes
        patchStrategicMerge:
          spec:
            template:
              spec:
                volumes:
                - (emptyDir):
                    +(sizeLimit): 20Mi
                  name: '{{ element.name }}'
    name: setDefault