Document Draino metrics

phanama · Aug 28, 2018 · eb28ba8 · eb28ba8
1 parent 9137608
commit eb28ba8
Showing 1 changed file with 21 additions and 3 deletions.
diff --git a/README.md b/README.md
@@ -11,7 +11,7 @@ wrong with a node - for instance by watching node logs or running a script. The
 Cluster Autoscaler can be configured to delete nodes that are underutilised.
 Adding Draino to the mix enables autoremediation:
 
-1. The Node Problem Detector detects a permanent node issue and sets the
+1. The Node Problem Detector detects a permanent node problem and sets the
    corresponding node condition.
 2. Draino notices the node condition. It immediately cordons the node to prevent
    new pods being scheduled there, and schedules a drain of the node.
@@ -43,7 +43,7 @@ Flags:
                                grace period for it to have been deleted.
       --drain-buffer=10m0s     Minimum time between starting each drain. Nodes
                                are always cordoned immediately.
-      --node-label=KEY=VALUE ...  
+      --node-label=KEY=VALUE ...
                                Only nodes with this label will be eligible for
                                cordoning and draining. May be specified multiple
                                times.
@@ -56,4 +56,22 @@ Args:
 ## Deployment
 Draino is automatically built from master and pushed to the [Docker Hub](https://hub.docker.com/r/negz/draino/).
 Builds are tagged `negz/draino:latest` and `negz/drain:$(git rev-parse --short HEAD)`.
-An [example Kubernetes deployment manifest](manifest.yml) is provided.
+An [example Kubernetes deployment manifest](manifest.yml) is provided.
+
+## Monitoring
+Draino provides a simple healthcheck endpoint at `/healthz` and Prometheus
+metrics at `/metrics`. The following metrics exist:
+
+```bash
+$ kubectl -n kube-system exec -it ${DRAINO_POD} -- apk add curl
+$ kubectl -n kube-system exec -it ${DRAINO_POD} -- curl http://localhost:10002/metrics
+# HELP draino_nodes_cordoned Number of nodes cordoned.
+# TYPE draino_nodes_cordoned counter
+draino_nodes_cordoned{node_name="coolnode",result="succeeded"} 1
+draino_nodes_cordoned{node_name="ambivalentnode",result="succeeded"} 1
+draino_nodes_cordoned{node_name="lamenode",result="failed"} 1
+# HELP draino_nodes_drained Number of nodes drained.
+# TYPE draino_nodes_drained counter
+draino_nodes_drained{node_name="coolnode",result="succeeded"} 1
+draino_nodes_drained{node_name="ambivalentnode",result="failed"} 1
+```