OPA Gatekeeper Restrict Privileged Containers within Deployment

noprivilegedconstrainttemplate.yaml

apiVersion: templates.gatekeeper.sh/v1beta1
kind: ConstraintTemplate
metadata:
  name: noprivileged
spec:
  crd:
    spec:
      names:
        kind: NoPrivileged
        listKind:  NoPrivilegedList
        plural:  NoPrivileged
        singular:  NoPrivilegeds
  targets:
    - target: admission.k8s.gatekeeper.sh
      rego: |
        package noprivileged
        
        violation[{"msg": msg, "details": {}}] {
            c := input.review.object.spec.template.spec.containers[_]
            c.securityContext.privileged
            msg := sprintf("Privileged container is not allowed: %v, securityContext: %v", [c.name, c.securityContext])
        }
        input_containers[c] {
            c := input.review.object.spec.template.spec.containers[_]
        }
        input_containers[c] {
            c := input.review.object.spec.template.spec.initContainers[_]
        }
---
apiVersion: constraints.gatekeeper.sh/v1beta1
kind: NoPrivileged
metadata:
  name: noprivileged
spec:
  match:
    kinds:
      - apiGroups: ["apps"]
        apiVersions: ["v1","v1beta1"]
        kinds: ["Deployment"]

Helpful links down below:

• https://dzone.com/articles/opa-and-gatekeeper-opa-or-gatekeeper
• https://medium.com/@bikramgupta/using-opa-and-gatekeeper-for-admission-control-policies-709c749c76ff
• https://www.infoq.com/news/2019/09/opa-gatekeeper-kubernetes/