Merge pull request #42617 from MrHohn/dns-autoscaler-rbac

Automatic merge from submit-queue

Moves dns-horizontal-autoscaler to a separate service account

Similar to #38816.

As one of the cluster add-ons, dns-horizontal-autoscaler is now using the default service account in kube-system namespace, which is introduced by https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/e2e-rbac-bindings/random-addon-grabbag.yaml for the ease of transition. This default service account will be removed in the future.

This PR subdivides dns-horizontal-autoscaler to a separate service account and setup the necessary permissions.

@bowei 

**Release note**:

```release-note
NONE
```

cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler-rbac.yaml

@@ -0,0 +1,58 @@
+# Copyright 2016 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+kind: ServiceAccount
+apiVersion: v1
+metadata:
+  name: kube-dns-autoscaler
+  namespace: kube-system
+  labels:
+    addonmanager.kubernetes.io/mode: Reconcile
+---
+kind: ClusterRole
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: system:kube-dns-autoscaler
+  labels:
+    addonmanager.kubernetes.io/mode: Reconcile
+rules:
+  - apiGroups: [""]
+    resources: ["nodes"]
+    verbs: ["list"]
+  - apiGroups: [""]
+    resources: ["replicationcontrollers/scale"]
+    verbs: ["get", "update"]
+  - apiGroups: ["extensions"]
+    resources: ["deployments/scale", "replicasets/scale"]
+    verbs: ["get", "update"]
+# Remove the configmaps rule once below issue is fixed:
+# kubernetes-incubator/cluster-proportional-autoscaler#16
+  - apiGroups: [""]
+    resources: ["configmaps"]
+    verbs: ["get", "create"]
+---
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: system:kube-dns-autoscaler
+  labels:
+    addonmanager.kubernetes.io/mode: Reconcile
+subjects:
+  - kind: ServiceAccount
+    name: kube-dns-autoscaler
+    namespace: kube-system
+roleRef:
+  kind: ClusterRole
+  name: system:kube-dns-autoscaler
+  apiGroup: rbac.authorization.k8s.io

cluster/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml

@@ -50,3 +50,4 @@ spec:
       tolerations:
       - key: "CriticalAddonsOnly"
         operator: "Exists"
+      serviceAccountName: kube-dns-autoscaler