Enforce AppProject with clusterResourceBlacklist in CEL expressions

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: appproject-clusterresourceblacklist
 5  annotations:
 6    policies.kyverno.io/title: Enforce AppProject with clusterResourceBlacklist in CEL expressions
 7    policies.kyverno.io/category: Argo in CEL 
 8    policies.kyverno.io/severity: medium
 9    kyverno.io/kyverno-version: 1.11.0
10    policies.kyverno.io/minversion: 1.11.0
11    kyverno.io/kubernetes-version: "1.26-1.27"
12    policies.kyverno.io/subject: AppProject
13    policies.kyverno.io/description: >-
14      An AppProject may optionally specify clusterResourceBlacklist which is a blacklisted
15      group of cluster resources. This is often a good practice to ensure AppProjects do
16      not allow more access than needed. This policy is a combination of two rules which
17      enforce that all AppProjects specify clusterResourceBlacklist and that their group
18      and kind have wildcards as values.
19spec:
20  validationFailureAction: Audit
21  background: true
22  rules:
23    - name: has-wildcard-and-validate-clusterresourceblacklist
24      match:
25        any:
26        - resources:
27            kinds:
28              - AppProject
29            operations:
30            - CREATE
31            - UPDATE
32      validate:
33        cel:
34          expressions:
35            - expression: "has(object.spec.clusterResourceBlacklist)"
36              message: "AppProject must specify clusterResourceBlacklist."
37            - expression: "object.spec.clusterResourceBlacklist.all(element, element.group.contains('*') && element.kind.contains('*'))"
38              message: "Wildcards must be present in group and kind for clusterResourceBlacklist."