apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: disallow-latest-tag-events-creation
  annotations:
    policies.kyverno.io/title: Disallow Latest Tag
    policies.kyverno.io/category: Best Practices
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: Pod
    policies.kyverno.io/description: >-
      The ':latest' tag is mutable and can lead to unexpected errors if the
      image changes. A best practice is to use an immutable tag that maps to
      a specific version of an application Pod. This policy validates that the image
      specifies a tag and that it is not called `latest`.      
spec:
  validationFailureAction: Enforce
  background: true
  rules:
  - name: validate-image-tag
    match:
      resources:
        kinds:
        - Pod
    validate:
      message: "An image tag is required (:latest is not allowed)"
      pattern:
        spec:
          containers:
          - image: "!*:latest & *:*"