npm/testpolicies/allow-ns-dev-and-app-backend-to-app-frontend.yaml

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all-policy
  namespace: testnamespace
spec:
  policyTypes:
    - Ingress
  podSelector:
    matchLabels:
      app: "frontend"
  ingress:
    - from:
        - podSelector:
            matchLabels:
              app: backend
          namespaceSelector:
            matchLabels:
              ns: dev