Disallow Latest Tag

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: disallow-latest-tag
 5  annotations:
 6    policies.kyverno.io/title: Disallow Latest Tag
 7    policies.kyverno.io/category: Best Practices
 8    policies.kyverno.io/minversion: 1.6.0
 9    policies.kyverno.io/severity: medium
10    policies.kyverno.io/subject: Pod
11    policies.kyverno.io/description: >-
12      The ':latest' tag is mutable and can lead to unexpected errors if the
13      image changes. A best practice is to use an immutable tag that maps to
14      a specific version of an application Pod. This policy validates that the image
15      specifies a tag and that it is not called `latest`.      
16spec:
17  validationFailureAction: Audit
18  background: true
19  rules:
20  - name: require-image-tag
21    match:
22      any:
23      - resources:
24          kinds:
25          - Pod
26    validate:
27      message: "An image tag is required."
28      foreach:
29        - list: "request.object.spec.containers"
30          pattern:
31            image: "*:*"
32        - list: "request.object.spec.initContainers"
33          pattern:
34            image: "*:*"
35        - list: "request.object.spec.ephemeralContainers"
36          pattern:
37            image: "*:*"
38  - name: validate-image-tag
39    match:
40      any:
41      - resources:
42          kinds:
43          - Pod
44    validate:
45      message: "Using a mutable image tag e.g. 'latest' is not allowed."
46      foreach:
47        - list: "request.object.spec.containers"
48          pattern:
49            image: "!*:latest"
50        - list: "request.object.spec.initContainers"
51          pattern:
52            image: "!*:latest"
53        - list: "request.object.spec.ephemeralContainers"
54          pattern:
55            image: "!*:latest"