run kubedns as system:serviceaccount:kube-system:kube-dns; but dns does NOT work

roles/kubernetes-apps/ansible/tasks/main.yml

@@ -13,6 +13,7 @@
     src: "{{item.file}}"
     dest: "{{kube_config_dir}}/{{item.file}}"
   with_items:
+    - {name: kube-dns, file: kubedns-serviceaccount.yml, type: serviceaccount}
     - {name: kubedns, file: kubedns-deploy.yml, type: deployment}
     - {name: kubedns, file: kubedns-svc.yml, type: svc}
     - {name: kubedns-autoscaler, file: kubedns-autoscaler.yml, type: deployment}

roles/kubernetes-apps/ansible/templates/kubedns-deploy.yml

@@ -114,3 +114,4 @@ spec:
         - containerPort: 8080
           protocol: TCP
       dnsPolicy: Default  # Don't use cluster DNS.
+      serviceAccountName: kube-dns

roles/kubernetes-apps/ansible/templates/kubedns-serviceaccount.yml

@@ -0,0 +1,5 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: kube-dns
+  namespace: {{ system_namespace }}