Validate User ID, Group ID, and FS Group

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: validate-userid-groupid-fsgroup
  annotations:
    policies.kyverno.io/title: Validate User ID, Group ID, and FS Group 
    policies.kyverno.io/category: Sample
    policies.kyverno.io/description: >-
      All processes inside the pod can be made to run with specific user and groupID 
      by setting 'runAsUser' and 'runAsGroup' respectively. 'fsGroup' can be specified 
      to make sure any file created in the volume with have the specified groupID. 
      These options can be used to validate the IDs used for user and group.
spec:
  rules:
  - name: validate-userid
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: "User ID should be 1000."
      pattern:
        spec:
          securityContext:
            runAsUser: '1000'
  - name: validate-groupid
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: "Group ID should be 3000."
      pattern:
        spec:
          securityContext:
            runAsGroup: '3000'
  - name: validate-fsgroup
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: "fsgroup should be 2000."
      pattern:
        spec:
          securityContext:
            fsGroup: '2000'