Registration of custom function to map container name to prometheus labels

cadvisor.go

@@ -78,11 +78,13 @@ func main() {
 	mux := http.DefaultServeMux
 
 	// Register all HTTP handlers.
-	err = cadvisorHttp.RegisterHandlers(mux, containerManager, *httpAuthFile, *httpAuthRealm, *httpDigestFile, *httpDigestRealm, *prometheusEndpoint)
+	err = cadvisorHttp.RegisterHandlers(mux, containerManager, *httpAuthFile, *httpAuthRealm, *httpDigestFile, *httpDigestRealm)
 	if err != nil {
 		glog.Fatalf("Failed to register HTTP handlers: %v", err)
 	}
 
+	cadvisorHttp.RegisterPrometheusHandler(mux, containerManager, *prometheusEndpoint, nil)
+
 	// Start the manager.
 	if err := containerManager.Start(); err != nil {
 		glog.Fatalf("Failed to start container manager: %v", err)

http/handlers.go

@@ -31,7 +31,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-func RegisterHandlers(mux httpMux.Mux, containerManager manager.Manager, httpAuthFile, httpAuthRealm, httpDigestFile, httpDigestRealm, prometheusEndpoint string) error {
+func RegisterHandlers(mux httpMux.Mux, containerManager manager.Manager, httpAuthFile, httpAuthRealm, httpDigestFile, httpDigestRealm string) error {
 	// Basic health handler.
 	if err := healthz.RegisterHandler(mux); err != nil {
 		return fmt.Errorf("failed to register healthz handler: %s", err)
@@ -85,13 +85,15 @@ func RegisterHandlers(mux httpMux.Mux, containerManager manager.Manager, httpAut
 		}
 	}
 
-	collector := metrics.NewPrometheusCollector(containerManager)
-	prometheus.MustRegister(collector)
-	http.Handle(prometheusEndpoint, prometheus.Handler())
-
 	return nil
 }
 
+func RegisterPrometheusHandler(mux httpMux.Mux, containerManager manager.Manager, prometheusEndpoint string, containerNameToLabelsFunc metrics.ContainerNameToLabelsFunc) {
+	collector := metrics.NewPrometheusCollector(containerManager, containerNameToLabelsFunc)
+	prometheus.MustRegister(collector)
+	mux.Handle(prometheusEndpoint, prometheus.Handler())
+}
+
 func staticHandlerNoAuth(w http.ResponseWriter, r *http.Request) {
 	err := static.HandleRequest(w, r.URL)
 	if err != nil {

metrics/prometheus.go

@@ -68,17 +68,21 @@ func (cm *containerMetric) desc(baseLabels []string) *prometheus.Desc {
 	return prometheus.NewDesc(cm.name, cm.help, append(baseLabels, cm.extraLabels...), nil)
 }
 
+type ContainerNameToLabelsFunc func(containerName string) map[string]string
+
 // PrometheusCollector implements prometheus.Collector.
 type PrometheusCollector struct {
-	infoProvider     infoProvider
-	errors           prometheus.Gauge
-	containerMetrics []containerMetric
+	infoProvider          infoProvider
+	errors                prometheus.Gauge
+	containerMetrics      []containerMetric
+	containerNameToLabels ContainerNameToLabelsFunc
 }
 
 // NewPrometheusCollector returns a new PrometheusCollector.
-func NewPrometheusCollector(infoProvider infoProvider) *PrometheusCollector {
+func NewPrometheusCollector(infoProvider infoProvider, f ContainerNameToLabelsFunc) *PrometheusCollector {
 	c := &PrometheusCollector{
-		infoProvider: infoProvider,
+		infoProvider:          infoProvider,
+		containerNameToLabels: f,
 		errors: prometheus.NewGauge(prometheus.GaugeOpts{
 			Namespace: "container",
 			Name:      "scrape_error",
@@ -500,6 +504,14 @@ func (c *PrometheusCollector) collectContainersInfo(ch chan<- prometheus.Metric)
 		}
 		baseLabelValues := []string{id, name, image}[:len(baseLabels)]
 
+		if c.containerNameToLabels != nil {
+			newLabels := c.containerNameToLabels(name)
+			for k, v := range newLabels {
+				baseLabels = append(baseLabels, k)
+				baseLabelValues = append(baseLabelValues, v)
+			}
+		}
+
 		// Container spec
 		desc := prometheus.NewDesc("container_start_time_seconds", "Start time of the container since unix epoch in seconds.", baseLabels, nil)
 		ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(container.Spec.CreationTime.Unix()), baseLabelValues...)

metrics/prometheus_test.go

@@ -152,7 +152,7 @@ func (p testSubcontainersInfoProvider) SubcontainersInfo(string, *info.Container
 }
 
 func TestPrometheusCollector(t *testing.T) {
-	prometheus.MustRegister(NewPrometheusCollector(testSubcontainersInfoProvider{}))
+	prometheus.MustRegister(NewPrometheusCollector(testSubcontainersInfoProvider{}, nil))
 
 	rw := httptest.NewRecorder()
 	prometheus.Handler().ServeHTTP(rw, &http.Request{})