Add Node.js mixin (grafana#413)

README.md

@@ -14,6 +14,9 @@ This repository contains various Jsonnet libraries we use at Grafana Labs:
 * [`memcached-mixin`](memcached-mixin/): A set of reuseable and extensible dashboards
   for Memcached.
 
+* [`nodejs-mixin`](nodejs-mixin/): A set of reusable and extensible dashboards
+  for Node.js.
+
 * [`oauth2-proxy`](oauth2-proxy/): A jsonnet configuration for deploying bitly's
   OAuth proxy to Kubernetes.
 

nodejs-mixin/.gitignore

@@ -0,0 +1,3 @@
+/alerts.yaml
+/rules.yaml
+dashboards_out

nodejs-mixin/README.md

@@ -0,0 +1,18 @@
+# Node.js Mixin
+
+The Node.js Mixin is a set of configurable, reusable, and extensible alerts and dashboards based on the default metrics exported by the [prom-client](https://github.com/siimon/prom-client). The mixin creates alerting rules for Prometheus and suitable dashboard descriptions for Grafana.
+
+To use them, you need to have `mixtool` and `jsonnetfmt` installed. If you have a working Go development environment, it's easiest to run the following:
+
+```bash
+$ go get github.com/monitoring-mixins/mixtool/cmd/mixtool
+$ go get github.com/google/go-jsonnet/cmd/jsonnetfmt
+```
+
+You can then build the Prometheus rules file `alerts.yaml` and a directory `dashboard_out` with the JSON dashboard files for Grafana:
+
+```bash
+$ make build
+```
+
+For more advanced uses of mixins, see [Prometheus Monitoring Mixins docs](https://github.com/monitoring-mixins/docs).

nodejs-mixin/alerts/alerts.yaml

@@ -0,0 +1,11 @@
+groups:
+  - name: NodejsAlerts
+    rules:
+      - alert: NodejsDown
+        expr: process_start_time_seconds != 1
+        for: 5m
+        labels:
+          severity: critical
+        annotations:
+          description: 'Node.js {{$labels.job}} on {{$labels.instance}} is not up.'
+          summary: Node.js not up