migrate scheduler metrics endpoint to metrics stability framework

cmd/kube-scheduler/BUILD

@@ -20,10 +20,9 @@ go_library(
     importpath = "k8s.io/kubernetes/cmd/kube-scheduler",
     deps = [
         "//cmd/kube-scheduler/app:go_default_library",
-        "//pkg/util/prometheusclientgo:go_default_library",
-        "//pkg/version/prometheus:go_default_library",
         "//staging/src/k8s.io/component-base/cli/flag:go_default_library",
         "//staging/src/k8s.io/component-base/logs:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics/prometheus/clientgo:go_default_library",
         "//vendor/github.com/spf13/pflag:go_default_library",
     ],
 )

cmd/kube-scheduler/app/BUILD

@@ -36,7 +36,7 @@ go_library(
         "//staging/src/k8s.io/client-go/tools/leaderelection:go_default_library",
         "//staging/src/k8s.io/component-base/cli/flag:go_default_library",
         "//staging/src/k8s.io/component-base/cli/globalflag:go_default_library",
-        "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics/legacyregistry:go_default_library",
         "//vendor/github.com/spf13/cobra:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
     ],

cmd/kube-scheduler/app/server.go

@@ -25,6 +25,8 @@ import (
 	"os"
 	goruntime "runtime"
 
+	"github.com/spf13/cobra"
+
 	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/apiserver/pkg/authentication/authenticator"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
@@ -39,6 +41,8 @@ import (
 	"k8s.io/client-go/tools/leaderelection"
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/cli/globalflag"
+	"k8s.io/component-base/metrics/legacyregistry"
+	"k8s.io/klog"
 	schedulerserverconfig "k8s.io/kubernetes/cmd/kube-scheduler/app/config"
 	"k8s.io/kubernetes/cmd/kube-scheduler/app/options"
 	"k8s.io/kubernetes/pkg/api/legacyscheme"
@@ -51,10 +55,6 @@ import (
 	utilflag "k8s.io/kubernetes/pkg/util/flag"
 	"k8s.io/kubernetes/pkg/version"
 	"k8s.io/kubernetes/pkg/version/verflag"
-
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/spf13/cobra"
-	"k8s.io/klog"
 )
 
 // Option configures a framework.Registry.
@@ -294,7 +294,7 @@ func buildHandlerChain(handler http.Handler, authn authenticator.Request, authz
 
 func installMetricHandler(pathRecorderMux *mux.PathRecorderMux) {
 	configz.InstallHandler(pathRecorderMux)
-	defaultMetricsHandler := prometheus.Handler().ServeHTTP
+	defaultMetricsHandler := legacyregistry.Handler().ServeHTTP
 	pathRecorderMux.HandleFunc("/metrics", func(w http.ResponseWriter, req *http.Request) {
 		if req.Method == "DELETE" {
 			metrics.Reset()

cmd/kube-scheduler/scheduler.go

@@ -25,9 +25,8 @@ import (
 
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/logs"
+	_ "k8s.io/component-base/metrics/prometheus/clientgo"
 	"k8s.io/kubernetes/cmd/kube-scheduler/app"
-	_ "k8s.io/kubernetes/pkg/util/prometheusclientgo" // load all the prometheus client-go plugins
-	_ "k8s.io/kubernetes/pkg/version/prometheus"      // for version metric registration
 )
 
 func main() {

pkg/controller/volume/scheduling/BUILD

@@ -26,6 +26,8 @@ go_library(
         "//staging/src/k8s.io/client-go/kubernetes:go_default_library",
         "//staging/src/k8s.io/client-go/listers/storage/v1:go_default_library",
         "//staging/src/k8s.io/client-go/tools/cache:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics/legacyregistry:go_default_library",
         "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",
     ],

pkg/controller/volume/scheduling/scheduler_bind_cache_metrics.go

@@ -18,6 +18,9 @@ package scheduling
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
+
+	"k8s.io/component-base/metrics"
+	"k8s.io/component-base/metrics/legacyregistry"
 )
 
 // VolumeSchedulerSubsystem - subsystem name used by scheduler
@@ -25,30 +28,33 @@ const VolumeSchedulerSubsystem = "scheduler_volume"
 
 var (
 	// VolumeBindingRequestSchedulerBinderCache tracks the number of volume binder cache operations.
-	VolumeBindingRequestSchedulerBinderCache = prometheus.NewCounterVec(
+	VolumeBindingRequestSchedulerBinderCache = metrics.NewCounterVec(
-		prometheus.CounterOpts{
+		&metrics.CounterOpts{
-			Subsystem: VolumeSchedulerSubsystem,
+			Subsystem:      VolumeSchedulerSubsystem,
-			Name:      "binder_cache_requests_total",
+			Name:           "binder_cache_requests_total",
-			Help:      "Total number for request volume binding cache",
+			Help:           "Total number for request volume binding cache",
+			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{"operation"},
 	)
 	// VolumeSchedulingStageLatency tracks the latency of volume scheduling operations.
-	VolumeSchedulingStageLatency = prometheus.NewHistogramVec(
+	VolumeSchedulingStageLatency = metrics.NewHistogramVec(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: VolumeSchedulerSubsystem,
+			Subsystem:      VolumeSchedulerSubsystem,
-			Name:      "scheduling_duration_seconds",
+			Name:           "scheduling_duration_seconds",
-			Help:      "Volume scheduling stage latency",
+			Help:           "Volume scheduling stage latency",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{"operation"},
 	)
 	// VolumeSchedulingStageFailed tracks the number of failed volume scheduling operations.
-	VolumeSchedulingStageFailed = prometheus.NewCounterVec(
+	VolumeSchedulingStageFailed = metrics.NewCounterVec(
-		prometheus.CounterOpts{
+		&metrics.CounterOpts{
-			Subsystem: VolumeSchedulerSubsystem,
+			Subsystem:      VolumeSchedulerSubsystem,
-			Name:      "scheduling_stage_error_total",
+			Name:           "scheduling_stage_error_total",
-			Help:      "Volume scheduling stage error count",
+			Help:           "Volume scheduling stage error count",
+			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{"operation"},
 	)
@@ -57,7 +63,7 @@ var (
 // RegisterVolumeSchedulingMetrics is used for scheduler, because the volume binding cache is a library
 // used by scheduler process.
 func RegisterVolumeSchedulingMetrics() {
-	prometheus.MustRegister(VolumeBindingRequestSchedulerBinderCache)
+	legacyregistry.MustRegister(VolumeBindingRequestSchedulerBinderCache)
-	prometheus.MustRegister(VolumeSchedulingStageLatency)
+	legacyregistry.MustRegister(VolumeSchedulingStageLatency)
-	prometheus.MustRegister(VolumeSchedulingStageFailed)
+	legacyregistry.MustRegister(VolumeSchedulingStageFailed)
 }

pkg/scheduler/internal/queue/scheduling_queue_test.go

@@ -1217,6 +1217,7 @@ func TestPodTimestamp(t *testing.T) {
 func TestPendingPodsMetric(t *testing.T) {
 	total := 50
 	timestamp := time.Now()
+	metrics.Register()
 	var pInfos = make([]*framework.PodInfo, 0, total)
 	for i := 1; i <= total; i++ {
 		p := &framework.PodInfo{
@@ -1312,9 +1313,9 @@ func TestPendingPodsMetric(t *testing.T) {
 	}
 
 	resetMetrics := func() {
-		metrics.ActivePods.Set(0)
+		metrics.ActivePods().Set(0)
-		metrics.BackoffPods.Set(0)
+		metrics.BackoffPods().Set(0)
-		metrics.UnschedulablePods.Set(0)
+		metrics.UnschedulablePods().Set(0)
 	}
 
 	for _, test := range tests {
@@ -1329,7 +1330,7 @@ func TestPendingPodsMetric(t *testing.T) {
 
 			var activeNum, backoffNum, unschedulableNum float64
 			metricProto := &dto.Metric{}
-			if err := metrics.ActivePods.Write(metricProto); err != nil {
+			if err := metrics.ActivePods().Write(metricProto); err != nil {
 				t.Errorf("error writing ActivePods metric: %v", err)
 			}
 			activeNum = metricProto.Gauge.GetValue()
@@ -1337,7 +1338,7 @@ func TestPendingPodsMetric(t *testing.T) {
 				t.Errorf("ActivePods: Expected %v, got %v", test.expected[0], activeNum)
 			}
 
-			if err := metrics.BackoffPods.Write(metricProto); err != nil {
+			if err := metrics.BackoffPods().Write(metricProto); err != nil {
 				t.Errorf("error writing BackoffPods metric: %v", err)
 			}
 			backoffNum = metricProto.Gauge.GetValue()
@@ -1345,7 +1346,7 @@ func TestPendingPodsMetric(t *testing.T) {
 				t.Errorf("BackoffPods: Expected %v, got %v", test.expected[1], backoffNum)
 			}
 
-			if err := metrics.UnschedulablePods.Write(metricProto); err != nil {
+			if err := metrics.UnschedulablePods().Write(metricProto); err != nil {
 				t.Errorf("error writing UnschedulablePods metric: %v", err)
 			}
 			unschedulableNum = metricProto.Gauge.GetValue()

pkg/scheduler/metrics/BUILD

@@ -11,6 +11,8 @@ go_library(
     importpath = "k8s.io/kubernetes/pkg/scheduler/metrics",
     deps = [
         "//pkg/controller/volume/scheduling:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics/legacyregistry:go_default_library",
         "//vendor/github.com/prometheus/client_golang/prometheus:go_default_library",
     ],
 )

pkg/scheduler/metrics/metric_recorder.go

@@ -17,7 +17,7 @@ limitations under the License.
 package metrics
 
 import (
-	"github.com/prometheus/client_golang/prometheus"
+	"k8s.io/component-base/metrics"
 )
 
 // MetricRecorder represents a metric recorder which takes action when the
@@ -32,27 +32,27 @@ var _ MetricRecorder = &PendingPodsRecorder{}
 
 // PendingPodsRecorder is an implementation of MetricRecorder
 type PendingPodsRecorder struct {
-	recorder prometheus.Gauge
+	recorder metrics.GaugeMetric
 }
 
 // NewActivePodsRecorder returns ActivePods in a Prometheus metric fashion
 func NewActivePodsRecorder() *PendingPodsRecorder {
 	return &PendingPodsRecorder{
-		recorder: ActivePods,
+		recorder: ActivePods(),
 	}
 }
 
 // NewUnschedulablePodsRecorder returns UnschedulablePods in a Prometheus metric fashion
 func NewUnschedulablePodsRecorder() *PendingPodsRecorder {
 	return &PendingPodsRecorder{
-		recorder: UnschedulablePods,
+		recorder: UnschedulablePods(),
 	}
 }
 
 // NewBackoffPodsRecorder returns BackoffPods in a Prometheus metric fashion
 func NewBackoffPodsRecorder() *PendingPodsRecorder {
 	return &PendingPodsRecorder{
-		recorder: BackoffPods,
+		recorder: BackoffPods(),
 	}
 }
 

pkg/scheduler/metrics/metrics.go

@@ -21,6 +21,9 @@ import (
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
+
+	"k8s.io/component-base/metrics"
+	"k8s.io/component-base/metrics/legacyregistry"
 	volumescheduling "k8s.io/kubernetes/pkg/controller/volume/scheduling"
 )
 
@@ -49,11 +52,12 @@ const (
 
 // All the histogram based metrics have 1ms as size for the smallest bucket.
 var (
-	scheduleAttempts = prometheus.NewCounterVec(
+	scheduleAttempts = metrics.NewCounterVec(
-		prometheus.CounterOpts{
+		&metrics.CounterOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "schedule_attempts_total",
+			Name:           "schedule_attempts_total",
-			Help:      "Number of attempts to schedule pods, by the result. 'unschedulable' means a pod could not be scheduled, while 'error' means an internal scheduler problem.",
+			Help:           "Number of attempts to schedule pods, by the result. 'unschedulable' means a pod could not be scheduled, while 'error' means an internal scheduler problem.",
+			StabilityLevel: metrics.ALPHA,
 		}, []string{"result"})
 	// PodScheduleSuccesses counts how many pods were scheduled.
 	PodScheduleSuccesses = scheduleAttempts.With(prometheus.Labels{"result": "scheduled"})
@@ -61,148 +65,162 @@ var (
 	PodScheduleFailures = scheduleAttempts.With(prometheus.Labels{"result": "unschedulable"})
 	// PodScheduleErrors counts how many pods could not be scheduled due to a scheduler error.
 	PodScheduleErrors = scheduleAttempts.With(prometheus.Labels{"result": "error"})
-	SchedulingLatency = prometheus.NewSummaryVec(
+	SchedulingLatency = metrics.NewSummaryVec(
-		prometheus.SummaryOpts{
+		&metrics.SummaryOpts{
 			Subsystem: SchedulerSubsystem,
 			Name:      SchedulingLatencyName,
 			Help:      "Scheduling latency in seconds split by sub-parts of the scheduling operation",
 			// Make the sliding window of 5h.
 			// TODO: The value for this should be based on some SLI definition (long term).
-			MaxAge: 5 * time.Hour,
+			MaxAge:         5 * time.Hour,
+			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{OperationLabel},
 	)
-	DeprecatedSchedulingLatency = prometheus.NewSummaryVec(
+	DeprecatedSchedulingLatency = metrics.NewSummaryVec(
-		prometheus.SummaryOpts{
+		&metrics.SummaryOpts{
 			Subsystem: SchedulerSubsystem,
 			Name:      DeprecatedSchedulingLatencyName,
 			Help:      "(Deprecated) Scheduling latency in seconds split by sub-parts of the scheduling operation",
 			// Make the sliding window of 5h.
 			// TODO: The value for this should be based on some SLI definition (long term).
-			MaxAge: 5 * time.Hour,
+			MaxAge:         5 * time.Hour,
+			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{OperationLabel},
 	)
-	E2eSchedulingLatency = prometheus.NewHistogram(
+	E2eSchedulingLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "e2e_scheduling_duration_seconds",
+			Name:           "e2e_scheduling_duration_seconds",
-			Help:      "E2e scheduling latency in seconds (scheduling algorithm + binding)",
+			Help:           "E2e scheduling latency in seconds (scheduling algorithm + binding)",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedE2eSchedulingLatency = prometheus.NewHistogram(
+	DeprecatedE2eSchedulingLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "e2e_scheduling_latency_microseconds",
+			Name:           "e2e_scheduling_latency_microseconds",
-			Help:      "(Deprecated) E2e scheduling latency in microseconds (scheduling algorithm + binding)",
+			Help:           "(Deprecated) E2e scheduling latency in microseconds (scheduling algorithm + binding)",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	SchedulingAlgorithmLatency = prometheus.NewHistogram(
+	SchedulingAlgorithmLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_duration_seconds",
+			Name:           "scheduling_algorithm_duration_seconds",
-			Help:      "Scheduling algorithm latency in seconds",
+			Help:           "Scheduling algorithm latency in seconds",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedSchedulingAlgorithmLatency = prometheus.NewHistogram(
+	DeprecatedSchedulingAlgorithmLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_latency_microseconds",
+			Name:           "scheduling_algorithm_latency_microseconds",
-			Help:      "(Deprecated) Scheduling algorithm latency in microseconds",
+			Help:           "(Deprecated) Scheduling algorithm latency in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	SchedulingAlgorithmPredicateEvaluationDuration = prometheus.NewHistogram(
+	SchedulingAlgorithmPredicateEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_predicate_evaluation_seconds",
+			Name:           "scheduling_algorithm_predicate_evaluation_seconds",
-			Help:      "Scheduling algorithm predicate evaluation duration in seconds",
+			Help:           "Scheduling algorithm predicate evaluation duration in seconds",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedSchedulingAlgorithmPredicateEvaluationDuration = prometheus.NewHistogram(
+	DeprecatedSchedulingAlgorithmPredicateEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_predicate_evaluation",
+			Name:           "scheduling_algorithm_predicate_evaluation",
-			Help:      "(Deprecated) Scheduling algorithm predicate evaluation duration in microseconds",
+			Help:           "(Deprecated) Scheduling algorithm predicate evaluation duration in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	SchedulingAlgorithmPriorityEvaluationDuration = prometheus.NewHistogram(
+	SchedulingAlgorithmPriorityEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_priority_evaluation_seconds",
+			Name:           "scheduling_algorithm_priority_evaluation_seconds",
-			Help:      "Scheduling algorithm priority evaluation duration in seconds",
+			Help:           "Scheduling algorithm priority evaluation duration in seconds",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedSchedulingAlgorithmPriorityEvaluationDuration = prometheus.NewHistogram(
+	DeprecatedSchedulingAlgorithmPriorityEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_priority_evaluation",
+			Name:           "scheduling_algorithm_priority_evaluation",
-			Help:      "(Deprecated) Scheduling algorithm priority evaluation duration in microseconds",
+			Help:           "(Deprecated) Scheduling algorithm priority evaluation duration in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	SchedulingAlgorithmPremptionEvaluationDuration = prometheus.NewHistogram(
+	SchedulingAlgorithmPremptionEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_preemption_evaluation_seconds",
+			Name:           "scheduling_algorithm_preemption_evaluation_seconds",
-			Help:      "Scheduling algorithm preemption evaluation duration in seconds",
+			Help:           "Scheduling algorithm preemption evaluation duration in seconds",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedSchedulingAlgorithmPremptionEvaluationDuration = prometheus.NewHistogram(
+	DeprecatedSchedulingAlgorithmPremptionEvaluationDuration = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "scheduling_algorithm_preemption_evaluation",
+			Name:           "scheduling_algorithm_preemption_evaluation",
-			Help:      "(Deprecated) Scheduling algorithm preemption evaluation duration in microseconds",
+			Help:           "(Deprecated) Scheduling algorithm preemption evaluation duration in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	BindingLatency = prometheus.NewHistogram(
+	BindingLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "binding_duration_seconds",
+			Name:           "binding_duration_seconds",
-			Help:      "Binding latency in seconds",
+			Help:           "Binding latency in seconds",
-			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(0.001, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	DeprecatedBindingLatency = prometheus.NewHistogram(
+	DeprecatedBindingLatency = metrics.NewHistogram(
-		prometheus.HistogramOpts{
+		&metrics.HistogramOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "binding_latency_microseconds",
+			Name:           "binding_latency_microseconds",
-			Help:      "(Deprecated) Binding latency in microseconds",
+			Help:           "(Deprecated) Binding latency in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
+			Buckets:        prometheus.ExponentialBuckets(1000, 2, 15),
+			StabilityLevel: metrics.ALPHA,
 		},
 	)
-	PreemptionVictims = prometheus.NewGauge(
+	PreemptionVictims = metrics.NewGauge(
-		prometheus.GaugeOpts{
+		&metrics.GaugeOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "pod_preemption_victims",
+			Name:           "pod_preemption_victims",
-			Help:      "Number of selected preemption victims",
+			Help:           "Number of selected preemption victims",
+			StabilityLevel: metrics.ALPHA,
 		})
-	PreemptionAttempts = prometheus.NewCounter(
+	PreemptionAttempts = metrics.NewCounter(
-		prometheus.CounterOpts{
+		&metrics.CounterOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "total_preemption_attempts",
+			Name:           "total_preemption_attempts",
-			Help:      "Total preemption attempts in the cluster till now",
+			Help:           "Total preemption attempts in the cluster till now",
+			StabilityLevel: metrics.ALPHA,
 		})
 
-	pendingPods = prometheus.NewGaugeVec(
+	pendingPods = metrics.NewGaugeVec(
-		prometheus.GaugeOpts{
+		&metrics.GaugeOpts{
-			Subsystem: SchedulerSubsystem,
+			Subsystem:      SchedulerSubsystem,
-			Name:      "pending_pods",
+			Name:           "pending_pods",
-			Help:      "Number of pending pods, by the queue type. 'active' means number of pods in activeQ; 'backoff' means number of pods in backoffQ; 'unschedulable' means number of pods in unschedulableQ.",
+			Help:           "Number of pending pods, by the queue type. 'active' means number of pods in activeQ; 'backoff' means number of pods in backoffQ; 'unschedulable' means number of pods in unschedulableQ.",
+			StabilityLevel: metrics.ALPHA,
 		}, []string{"queue"})
-	ActivePods        = pendingPods.With(prometheus.Labels{"queue": "active"})
-	BackoffPods       = pendingPods.With(prometheus.Labels{"queue": "backoff"})
-	UnschedulablePods = pendingPods.With(prometheus.Labels{"queue": "unschedulable"})
 
-	metricsList = []prometheus.Collector{
+	metricsList = []metrics.Registerable{
 		scheduleAttempts,
 		SchedulingLatency,
 		DeprecatedSchedulingLatency,
@@ -231,13 +249,27 @@ func Register() {
 	// Register the metrics.
 	registerMetrics.Do(func() {
 		for _, metric := range metricsList {
-			prometheus.MustRegister(metric)
+			legacyregistry.MustRegister(metric)
 		}
-
 		volumescheduling.RegisterVolumeSchedulingMetrics()
 	})
 }
 
+// ActivePods returns the pending pods metrics with the label active
+func ActivePods() metrics.GaugeMetric {
+	return pendingPods.With(prometheus.Labels{"queue": "active"})
+}
+
+// BackoffPods returns the pending pods metrics with the label backoff
+func BackoffPods() metrics.GaugeMetric {
+	return pendingPods.With(prometheus.Labels{"queue": "backoff"})
+}
+
+// UnschedulablePods returns the pending pods metrics with the label unschedulable
+func UnschedulablePods() metrics.GaugeMetric {
+	return pendingPods.With(prometheus.Labels{"queue": "unschedulable"})
+}
+
 // Reset resets metrics
 func Reset() {
 	SchedulingLatency.Reset()

staging/src/k8s.io/component-base/metrics/wrappers.go

@@ -61,6 +61,8 @@ type GaugeMetric interface {
 	Set(float64)
 	Inc()
 	Dec()
+	Add(float64)
+	Write(out *dto.Metric) error
 }
 
 // ObserverMetric captures individual observations.