disalow-default-ns.yaml

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: disallow-default-namespace
  annotations:
    pod-policies.kyverno.io/autogen-controllers: none
    policies.kyverno.io/title: Disallow Default Namespace
    policies.kyverno.io/minversion: 1.6.0
    policies.kyverno.io/category: Multi-Tenancy
    policies.kyverno.io/severity: medium
    policies.kyverno.io/subject: Pod
spec:
  validationFailureAction: Enforce
  failurePolicy: Fail
  background: true
  rules:
  - name: validate-namespace
    match:
      any:
      - resources:
          kinds:
          - Pod
    validate:
      message: "Não é possível utilizar o namespace default!"
      pattern:
        metadata:
          namespace: "!default"
  - name: validate-podcontroller-namespace
    match:
      any:
      - resources:
          kinds:
          - DaemonSet
          - Deployment
          - Job
          - StatefulSet
    validate:
      message: "Using 'default' namespace is not allowed for pod controllers."
      pattern:
        metadata:
          namespace: "!default"