Add runit exporter

exporter/exporter.go

@@ -80,12 +80,17 @@ func New(configFile string) (e exporter, err error) {
 		log.Fatalf("Couldn't attach collector: %s", err)
 	}
 
+	cr, err := NewRunitCollector(e.config, e.registry)
+	if err != nil {
+		log.Fatalf("Couldn't attach collector: %s", err)
+	}
+
 	cg, err := NewGmondCollector(e.config, e.registry)
 	if err != nil {
 		log.Fatalf("Couldn't attach collector: %s", err)
 	}
 
-	e.collectors = []Collector{&cn, &cg}
+	e.collectors = []Collector{&cn, &cr, &cg}
 
 	if e.config.ListeningAddress != "" {
 		e.listeningAddress = e.config.ListeningAddress

exporter/runit_collector.go

@@ -0,0 +1,79 @@
+package exporter
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/soundcloud/go-runit/runit"
+)
+
+type runitCollector struct {
+	name         string
+	config       config
+	state        prometheus.Gauge
+	stateDesired prometheus.Gauge
+	stateNormal  prometheus.Gauge
+}
+
+func NewRunitCollector(config config, registry prometheus.Registry) (runitCollector, error) {
+	c := runitCollector{
+		name:         "runit_collector",
+		config:       config,
+		state:        prometheus.NewGauge(),
+		stateDesired: prometheus.NewGauge(),
+		stateNormal:  prometheus.NewGauge(),
+	}
+
+	registry.Register(
+		"node_service_state",
+		"node_exporter: state of runit service.",
+		prometheus.NilLabels,
+		c.state,
+	)
+
+	registry.Register(
+		"node_service_desired_state",
+		"node_exporter: desired status of runit service.",
+		prometheus.NilLabels,
+		c.stateDesired,
+	)
+
+	registry.Register(
+		"node_service_normal_state",
+		"node_exporter: status of runit service.",
+		prometheus.NilLabels,
+		c.stateNormal,
+	)
+
+	return c, nil
+}
+
+func (c *runitCollector) Name() string { return c.name }
+
+func (c *runitCollector) Update() (updates int, err error) {
+	services, err := runit.GetServices()
+	if err != nil {
+		return 0, err
+	}
+
+	for _, service := range services {
+		status, err := service.Status()
+		if err != nil {
+			return 0, err
+		}
+
+		debug(c.Name(), "%s is %d on pid %d for %d seconds", service.Name, status.State, status.Pid, status.Duration)
+		labels := map[string]string{
+			"service": service.Name,
+		}
+
+		c.state.Set(labels, float64(status.State))
+		c.stateDesired.Set(labels, float64(status.Want))
+		if status.NormallyUp {
+			c.stateNormal.Set(labels, 1)
+		} else {
+			c.stateNormal.Set(labels, 1)
+		}
+		updates += 3
+	}
+
+	return updates, err
+}