Merge pull request #29291 from jimmidyson/prometheus-duplicate-labels

Automatic merge from submit-queue

Remove duplicate prometheus metrics

This was a relic from before Kubernetes set Docker labels properly. Cadvisor now properly exposes the Docker labels (e.g. `io.kubernetes.pod.name` as `io_kubernetes_pod_name`, etc) so this is no longer required & actually results in unnecessary duplicate Prometheus labels.

pkg/kubelet/cadvisor/cadvisor_linux.go

@@ -22,7 +22,6 @@ import (
 	"flag"
 	"fmt"
 	"net/http"
-	"regexp"
 	"time"
 
 	"github.com/golang/glog"
@@ -109,18 +108,7 @@ func (cc *cadvisorClient) exportHTTP(port uint) error {
 		return err
 	}
 
-	re := regexp.MustCompile(`^k8s_(?P<kubernetes_container_name>[^_\.]+)[^_]+_(?P<kubernetes_pod_name>[^_]+)_(?P<kubernetes_namespace>[^_]+)`)
-	reCaptureNames := re.SubexpNames()
-	cadvisorhttp.RegisterPrometheusHandler(mux, cc, "/metrics", func(name string) map[string]string {
-		extraLabels := map[string]string{}
-		matches := re.FindStringSubmatch(name)
-		for i, match := range matches {
-			if len(reCaptureNames[i]) > 0 {
-				extraLabels[re.SubexpNames()[i]] = match
-			}
-		}
-		return extraLabels
-	})
+	cadvisorhttp.RegisterPrometheusHandler(mux, cc, "/metrics", nil)
 
 	// Only start the http server if port > 0
 	if port > 0 {