<p>I am trying to setup Kubernetes <strong>autoscaler</strong> with Amazon AWS as described here: <a href="https://github.com/kubernetes/autoscaler/blob/master/cluster-autoscaler/cloudprovider/aws/README.md" rel="nofollow noreferrer">DOCS</a> but I am getting this error in my <strong>cluster-autoscaler</strong> pod logs:</p>

<pre><code>E0411 09:23:25.529212   1 static_autoscaler.go:118] Failed to update node registry: RequestError: send request failed caused by: Post https://autoscaling.us-west-2a.amazonaws.com/: dial tcp: lookup autoscaling.us-west-2a.amazonaws.com on 10.96.0.10:53: no such host
</code></pre>

<blockquote>
  <p>Context:</p>
</blockquote>

<p>I've created AWS Autoscaling Group named <strong>KubeAutoscale</strong> from Launch Configration with my custom instance AMI which has installed Ubuntu server 16.04 LTS (HVM) and Docker with Kubernetes (just raw install). </p>

<p>In AWS Autoscaling Group I've put 2 instances as minimum and maximum of 5 instances (they are in us-west-2a region) and I logged in on one of those 2 and setup Kubernetes cluster, logged in on other instance and add it to created cluster and logged again on master (first) instance run Autoscaler with configuration:</p>

<pre><code>---
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-addon: cluster-autoscaler.addons.k8s.io
    k8s-app: cluster-autoscaler
  name: cluster-autoscaler
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: cluster-autoscaler
  labels:
    k8s-addon: cluster-autoscaler.addons.k8s.io
    k8s-app: cluster-autoscaler
rules:
- apiGroups: [""]
  resources: ["events","endpoints"]
  verbs: ["create", "patch"]
- apiGroups: [""]
  resources: ["pods/eviction"]
  verbs: ["create"]
- apiGroups: [""]
  resources: ["pods/status"]
  verbs: ["update"]
- apiGroups: [""]
  resources: ["endpoints"]
  resourceNames: ["cluster-autoscaler"]
  verbs: ["get","update"]
- apiGroups: [""]
  resources: ["nodes"]
  verbs: ["watch","list","get","update"]
- apiGroups: [""]
  resources: ["pods","services","replicationcontrollers","persistentvolumeclaims","persistentvolumes"]
  verbs: ["watch","list","get"]
- apiGroups: ["extensions"]
  resources: ["replicasets","daemonsets"]
  verbs: ["watch","list","get"]
- apiGroups: ["policy"]
  resources: ["poddisruptionbudgets"]
  verbs: ["watch","list"]
- apiGroups: ["apps"]
  resources: ["statefulsets"]
  verbs: ["watch","list","get"]
- apiGroups: ["storage.k8s.io"]
  resources: ["storageclasses"]
  verbs: ["watch","list","get"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: cluster-autoscaler
  namespace: kube-system
  labels:
    k8s-addon: cluster-autoscaler.addons.k8s.io
    k8s-app: cluster-autoscaler
rules:
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["create"]
- apiGroups: [""]
  resources: ["configmaps"]
  resourceNames: ["cluster-autoscaler-status"]
  verbs: ["delete","get","update"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: cluster-autoscaler
  labels:
    k8s-addon: cluster-autoscaler.addons.k8s.io
    k8s-app: cluster-autoscaler
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-autoscaler
subjects:
  - kind: ServiceAccount
    name: cluster-autoscaler
    namespace: kube-system

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: cluster-autoscaler
  namespace: kube-system
  labels:
    k8s-addon: cluster-autoscaler.addons.k8s.io
    k8s-app: cluster-autoscaler
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: cluster-autoscaler
subjects:
  - kind: ServiceAccount
    name: cluster-autoscaler
    namespace: kube-system

---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: cluster-autoscaler
  namespace: kube-system
  labels:
    app: cluster-autoscaler
spec:
  replicas: 1
  selector:
    matchLabels:
      app: cluster-autoscaler
  template:
    metadata:
      labels:
        app: cluster-autoscaler
    spec:
      serviceAccountName: cluster-autoscaler
      containers:
        - image: k8s.gcr.io/cluster-autoscaler:v0.6.0
          name: cluster-autoscaler
          resources:
            limits:
              cpu: 100m
              memory: 300Mi
            requests:
              cpu: 100m
              memory: 300Mi
          command:
            - ./cluster-autoscaler
            - --v=4
            - --stderrthreshold=info
            - --cloud-provider=aws
            - --skip-nodes-with-local-storage=false
            - --nodes=2:5:KubeAutoscale
          env:
            - name: AWS_REGION
              value: us-west-2a
          volumeMounts:
            - name: ssl-certs
              mountPath: /etc/ssl/certs/ca-certificates.crt
              readOnly: true
          imagePullPolicy: "Always"
      volumes:
        - name: ssl-certs
          hostPath:
            path: "/etc/ssl/certs/ca-certificates.crt"
</code></pre>

<p>You have the configuration issue:</p>

<pre><code> env:
  - name: AWS_REGION
    value: us-west-2a
</code></pre>

<p>Your AWS region is <code>us-west-2</code>, but AZ is <code>us-west-2a</code>. That's why when Autoscaling generates the URL of autoscaling endpoint, the result is <code>https://autoscaling.us-west-2a.amazonaws.com/</code> instead of <code>https://autoscaling.us-west-2.amazonaws.com/</code> - which is the correct one.</p>

<p>To fix it, just set <code>AWS_REGION</code> to <code>us-west-2</code> instead of <code>us-west-2a</code>.</p>
