Add emptyDir sizeLimit

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: add-emptydir-sizelimit
  annotations:
    pod-policies.kyverno.io/autogen-controllers: none
    policies.kyverno.io/title: Add emptyDir sizeLimit
    policies.kyverno.io/category: Other
    policies.kyverno.io/subject: Pod
    policies.kyverno.io/minversion: 1.6.0
    kyverno.io/kyverno-version: 1.7.3,1.8.0-rc2
    kyverno.io/kubernetes-version: "1.24"
    policies.kyverno.io/description: When a Pod requests an emptyDir, by default it does not have a size limit which may allow it to consume excess or all of the space in the medium backing the volume. This can quickly overrun a Node and may result in a denial of service for other workloads. This policy adds a sizeLimit field to all Pods mounting emptyDir volumes, if not present, and sets it to 100Mi.
spec:
  rules:
    - name: mutate-emptydir
      match:
        any:
          - resources:
              kinds:
                - Pod
      mutate:
        foreach:
          - list: request.object.spec.volumes[]
            preconditions:
              all:
                - key: "{{element.keys(@)}}"
                  operator: AnyIn
                  value: emptyDir
                - key: "{{element.emptyDir.sizeLimit || ''}}"
                  operator: Equals
                  value: ""
            patchesJson6902: |-
              - path: "/spec/volumes/{{elementIndex}}/emptyDir/sizeLimit"
                op: add
                value: 100Mi