add kubelet prometheus resource metrics endpoint

pkg/kubelet/server/server.go

@@ -25,6 +25,7 @@ import (
 	"net/http"
 	"net/http/pprof"
 	"net/url"
+	"path"
 	"reflect"
 	goruntime "runtime"
 	"strconv"
@@ -59,6 +60,7 @@ import (
 	"k8s.io/kubernetes/pkg/apis/core/v1/validation"
 	"k8s.io/kubernetes/pkg/kubelet/apis/podresources"
 	podresourcesapi "k8s.io/kubernetes/pkg/kubelet/apis/podresources/v1alpha1"
+	"k8s.io/kubernetes/pkg/kubelet/apis/resourcemetrics/v1alpha1"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/prober"
 	"k8s.io/kubernetes/pkg/kubelet/server/portforward"
@@ -71,12 +73,13 @@ import (
 )
 
 const (
-	metricsPath         = "/metrics"
-	cadvisorMetricsPath = "/metrics/cadvisor"
-	proberMetricsPath   = "/metrics/probes"
-	specPath            = "/spec/"
-	statsPath           = "/stats/"
-	logsPath            = "/logs/"
+	metricsPath               = "/metrics"
+	cadvisorMetricsPath       = "/metrics/cadvisor"
+	resourceMetricsPathPrefix = "/metrics/resource"
+	proberMetricsPath         = "/metrics/probes"
+	specPath                  = "/spec/"
+	statsPath                 = "/stats/"
+	logsPath                  = "/logs/"
 )
 
 // Server is a http.Handler which exposes kubelet functionality over HTTP.
@@ -308,6 +311,12 @@ func (s *Server) InstallDefaultHandlers() {
 		promhttp.HandlerFor(r, promhttp.HandlerOpts{ErrorHandling: promhttp.ContinueOnError}),
 	)
 
+	v1alpha1ResourceRegistry := prometheus.NewRegistry()
+	v1alpha1ResourceRegistry.MustRegister(stats.NewPrometheusResourceMetricCollector(s.resourceAnalyzer, v1alpha1.Config()))
+	s.restfulCont.Handle(path.Join(resourceMetricsPathPrefix, v1alpha1.Version),
+		promhttp.HandlerFor(v1alpha1ResourceRegistry, promhttp.HandlerOpts{ErrorHandling: promhttp.ContinueOnError}),
+	)
+
 	// prober metrics are exposed under a different endpoint
 	p := prometheus.NewRegistry()
 	p.MustRegister(prober.ProberResults)