Restrict Ingress Classes

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: restrict-ingress-classes
 5  annotations:
 6    policies.kyverno.io/title: Restrict Ingress Classes
 7    policies.kyverno.io/category: Sample
 8    policies.kyverno.io/severity: medium
 9    policies.kyverno.io/subject: Ingress
10    policies.kyverno.io/minversion: 1.6.0
11    policies.kyverno.io/description: >-
12      Ingress classes should only be allowed which match up to deployed Ingress controllers
13      in the cluster. Allowing users to define classes which cannot be satisfied by a deployed
14      Ingress controller can result in either no or undesired functionality. This policy checks
15      Ingress resources and only allows those which define `HAProxy` or `nginx` in the respective
16      annotation. This annotation has largely been replaced as of Kubernetes 1.18 with the IngressClass
17      resource.
18spec:
19  validationFailureAction: Audit
20  background: true
21  rules:
22  - name: validate-ingress
23    match:
24      any:
25      - resources:
26          kinds:
27          - Ingress
28    validate:
29      message: "Unknown ingress class."
30      pattern:
31        metadata:
32          annotations:
33            kubernetes.io/ingress.class: "HAProxy | nginx"