Add node_exporter scrape target to Prometheus

Also filters out any non-system components from appearing in the
prometheus configuration.

examples/prometheus/prometheus.yaml

@@ -524,6 +524,15 @@ objects:
         - role: endpoints
 
         relabel_configs:
+        # only scrape infrastructure components
+        - source_labels: [__meta_kubernetes_namespace]
+          action: keep
+          regex: 'default|logging|metrics|kube-.+|openshift|openshift-.+'
+        # drop infrastructure components managed by other scrape targets
+        - source_labels: [__meta_kubernetes_service_name]
+          action: drop
+          regex: 'prometheus-node-exporter'
+        # only those that have requested scraping
         - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
           action: keep
           regex: true
@@ -540,14 +549,6 @@ objects:
           target_label: __address__
           regex: (.+)(?::\d+);(\d+)
           replacement: $1:$2
-        - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_username]
-          action: replace
-          target_label: __basic_auth_username__
-          regex: (.+)
-        - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_password]
-          action: replace
-          target_label: __basic_auth_password__
-          regex: (.+)
         - action: labelmap
           regex: __meta_kubernetes_service_label_(.+)
         - source_labels: [__meta_kubernetes_namespace]
@@ -557,8 +558,53 @@ objects:
           action: replace
           target_label: kubernetes_name
 
-      - job_name: 'openshift-template-service-broker'
+      # Scrape config for node-exporter, which is expected to be running on port 9100.
+      - job_name: 'kubernetes-nodes-exporter'
+
+        tls_config:
+          ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
+
+        kubernetes_sd_configs:
+        - role: node
+
+        metric_relabel_configs:
+        - source_labels: [__name__]
+          action: drop
+          regex: 'node_cpu|node_(disk|scrape_collector)_.+'
+        # preserve a subset of the network, netstat, vmstat, and filesystem series
+        - source_labels: [__name__]
+          action: replace
+          regex: '(node_(netstat_Ip_.+|vmstat_(nr|thp)_.+|filesystem_(free|size|device_error)|network_(transmit|receive)_(drop|errs)))'
+          target_label: __name__
+          replacement: renamed_$1
+        - source_labels: [__name__]
+          action: drop
+          regex: 'node_(netstat|vmstat|filesystem|network)_.+'
+        - source_labels: [__name__]
+          action: replace
+          regex: 'renamed_(.+)'
+          target_label: __name__
+          replacement: $1
+        # drop any partial expensive series
+        - source_labels: [__name__, device]
+          action: drop
+          regex: 'node_network_.+;veth.+'
+        - source_labels: [__name__, mountpoint]
+          action: drop
+          regex: 'node_filesystem_(free|size|device_error);([^/].*|/.+)'
+
+        relabel_configs:
+        - source_labels: [__address__]
+          regex: '(.*):10250'
+          replacement: '${1}:9100'
+          target_label: __address__
+        - source_labels: [__meta_kubernetes_node_label_kubernetes_io_hostname]
+          target_label: __instance__
+        - action: labelmap
+          regex: __meta_kubernetes_node_label_(.+)
 
+      # Scrape config for the template service broker
+      - job_name: 'openshift-template-service-broker'
         scheme: https
         tls_config:
           ca_file: /var/run/secrets/kubernetes.io/serviceaccount/service-ca.crt