Kubernetes config scrape node via api proxy (#2641)

* scrape kubelet metrics via api node proxy

* add manifests to setup serviceaccount, clusterrole and clusterrolebinding to work with rbac

* removed .cluster.local and added newline to address comments

documentation/examples/prometheus-kubernetes.yml

@@ -76,6 +76,12 @@ scrape_configs:
   relabel_configs:
   - action: labelmap
     regex: __meta_kubernetes_node_label_(.+)
+  - target_label: __address__
+    replacement: kubernetes.default.svc:443
+  - source_labels: [__meta_kubernetes_node_name]
+    regex: (.+)
+    target_label: __metrics_path__
+    replacement: /api/v1/nodes/${1}/proxy/metrics
 
 # Scrape config for service endpoints.
 #