Block Tekton TaskRun in CEL expressions

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: block-tekton-task-runs
 5  annotations:
 6    policies.kyverno.io/title: Block Tekton TaskRun in CEL expressions
 7    policies.kyverno.io/category: Tekton in CEL 
 8    policies.kyverno.io/severity: medium
 9    policies.kyverno.io/subject: TaskRun
10    kyverno.io/kyverno-version: 1.11.0
11    policies.kyverno.io/minversion: 1.11.0
12    kyverno.io/kubernetes-version: "1.26-1.27"
13    policies.kyverno.io/description: >-
14      Restrict creation of TaskRun resources to the Tekton pipelines controller.
15spec:
16  validationFailureAction: Audit
17  background: false
18  rules:
19  - name: check-taskrun-user
20    match:
21      any:
22      - resources:
23          kinds:
24            - TaskRun
25          operations:
26          - CREATE
27          - UPDATE
28    exclude:
29      any:
30      - subjects:
31        - kind: User 
32          name: "system:serviceaccount:tekton-pipelines:tekton-pipelines-controller"
33    validate:
34      cel:
35        expressions:
36          - expression: "false"
37            message: Creating a TaskRun is not allowed.