Configure Heapster to source metrics from Kubelet authenticated API

* Heapster can now get nodes (i.e. kubelets) from the apiserver and
source metrics from the Kubelet authenticated API (10250) instead of
the Kubelet HTTP read-only API (10255)
* https://github.com/kubernetes/heapster/blob/master/docs/source-configuration.md
* Use the heapster service account token via Kubelet bearer token
authn/authz.
* Permit Heapster to skip CA verification. The CA cert does not contain
IP SANs and cannot since nodes get random IPs that aren't known upfront.
Heapster obtains the node list from the apiserver, so the risk of
spoofing a node is limited. For the same reason, Prometheus scrapes
must skip CA verification for scraping Kubelet's provided by the apiserver.
* https://github.com/poseidon/typhoon/blob/v1.12.1/addons/prometheus/config.yaml#L68
* Create a heapster ClusterRole to work around the default Kubernetes
`system:heapster` ClusterRole lacking the proper GET `nodes/stats`
access. See https://github.com/kubernetes/heapster/issues/1936

CHANGES.md

@@ -10,6 +10,10 @@ Notable changes between versions.
 
 * Add `disk_iops` variable for EBS volume IOPS ([#314](https://github.com/poseidon/typhoon/pull/314))
 
+#### Addons
+
+* Configure Heapster to scrape Kubelets with bearer token auth ([#323](https://github.com/poseidon/typhoon/pull/323))
+
 ## v1.12.1
 
 * Kubernetes [v1.12.1](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.12.md#v1121)

addons/heapster/cluster-role-binding.yaml

@@ -5,7 +5,7 @@ metadata:
 roleRef:
   apiGroup: rbac.authorization.k8s.io
   kind: ClusterRole
-  name: system:heapster
+  name: heapster
 subjects:
 - kind: ServiceAccount
   name: heapster

addons/heapster/cluster-role.yaml

@@ -0,0 +1,30 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: heapster
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - events
+  - namespaces
+  - nodes
+  - pods
+  verbs:
+  - get
+  - list
+  - watch
+- apiGroups:
+  - extensions
+  resources:
+  - deployments
+  verbs:
+  - get
+  - list
+  - watch
+- apiGroups:
+  - ""
+  resources:
+  - nodes/stats
+  verbs:
+  - get

addons/heapster/deployment.yaml

@@ -23,7 +23,7 @@ spec:
           image: k8s.gcr.io/heapster-amd64:v1.5.4
           command:
             - /heapster
-            - --source=kubernetes.summary_api:''
+            - --source=kubernetes.summary_api:''?useServiceAccount=true&kubeletHttps=true&kubeletPort=10250&insecure=true
           livenessProbe:
             httpGet:
               path: /healthz