Apply a network policy to explicitly permit postgres

.gitlab-ci.yml

@@ -117,6 +117,7 @@ deploy-realworld:
     - kubectl get all
     - kubectl apply -f realworld/backend-service.yaml
     - kubectl apply -f realworld/frontend-service.yaml
+    - kubectl apply -f realworld/postgres-network-policy.yaml
     - kubectl apply -f realworld/ingress.yaml
 
 deploy-realworld-postgres:

realworld/postgres-network-policy.yaml

+apiVersion: extensions/v1beta1
+kind: NetworkPolicy
+metadata:
+  name: realworld-postgres-network-policy
+spec:
+  ingress:
+  - ports:
+    - port: 5432
+      protocol: TCP
+  podSelector:
+    matchLabels:
+      service: postgres
+      app: realworld
+  policyTypes:
+  - Ingress