Require Run As Non-Root User in CEL

 1apiVersion: kyverno.io/v1
 2kind: ClusterPolicy
 3metadata:
 4  name: require-run-as-non-root-user
 5  annotations:
 6    policies.kyverno.io/title: Require Run As Non-Root User in CEL
 7    policies.kyverno.io/category: Pod Security Standards (Restricted) in CEL
 8    policies.kyverno.io/severity: medium
 9    policies.kyverno.io/subject: Pod
10    policies.kyverno.io/minversion: 1.11.0
11    kyverno.io/kyverno-version: 1.11.0
12    kyverno.io/kubernetes-version: "1.26-1.27"
13    policies.kyverno.io/description: >-
14      Containers must be required to run as non-root users. This policy ensures
15      `runAsUser` is either unset or set to a number greater than zero.      
16spec:
17  validationFailureAction: Audit
18  background: true
19  rules:
20    - name: run-as-non-root-user
21      match:
22        any:
23        - resources:
24            kinds:
25              - Pod
26      validate:
27        cel:
28          expressions:
29            - expression: >-
30                !has(object.spec.securityContext) ||
31                !has(object.spec.securityContext.runAsUser) ||
32                object.spec.securityContext.runAsUser > 0                
33              message: >-
34                Running as root is not allowed. The field spec.securityContext.runAsUser must be unset or
35                set to a number greater than zero.                
36
37            - expression: >-
38                object.spec.containers.all(container, !has(container.securityContext) ||
39                !has(container.securityContext.runAsUser) ||
40                container.securityContext.runAsUser > 0)                
41              message: >-
42                Running as root is not allowed. The field spec.containers[*].securityContext.runAsUser must be unset or
43                set to a number greater than zero                
44
45            - expression: >-
46                !has(object.spec.initContainers) ||
47                object.spec.initContainers.all(container, !has(container.securityContext) ||
48                !has(container.securityContext.runAsUser) ||
49                container.securityContext.runAsUser > 0)                
50              message: >-
51                Running as root is not allowed. The field spec.initContainers[*].securityContext.runAsUser must be unset or
52                set to a number greater than zero                
53
54            - expression: >-
55                !has(object.spec.ephemeralContainers) ||
56                object.spec.ephemeralContainers.all(container, !has(container.securityContext) ||
57                !has(container.securityContext.runAsUser) ||
58                container.securityContext.runAsUser > 0)                
59              message: >-
60                Running as root is not allowed. The field spec.ephemeralContainers[*].securityContext.runAsUser must be unset or
61                set to a number greater than zero