vendor: revendor metrics-server, custom-metrics-apiserver

vendor/sigs.k8s.io/metrics-server/pkg/api/monitoring.go

@@ -0,0 +1,38 @@
+// Copyright 2020 The Kubernetes Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"k8s.io/component-base/metrics"
+)
+
+var (
+	metricFreshness = metrics.NewHistogramVec(
+		&metrics.HistogramOpts{
+			Namespace: "metrics_server",
+			Subsystem: "api",
+			Name:      "metric_freshness_seconds",
+			Help:      "Freshness of metrics exported",
+			Buckets:   metrics.ExponentialBuckets(1, 1.364, 20),
+		},
+		[]string{},
+	)
+)
+
+// RegisterAPIMetrics registers a histogram metric for the freshness of
+// exported metrics.
+func RegisterAPIMetrics(registrationFunc func(metrics.Registerable) error) error {
+	return registrationFunc(metricFreshness)
+}