Provides API for create const metric

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

@@ -0,0 +1,39 @@
+/*
+Copyright 2019 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 metrics
+
+import "github.com/prometheus/client_golang/prometheus"
+
+// ValueType is an enumeration of metric types that represent a simple value.
+type ValueType int
+
+// Possible values for the ValueType enum.
+const (
+	_ ValueType = iota
+	CounterValue
+	GaugeValue
+	UntypedValue
+)
+
+func (vt *ValueType) toPromValueType() prometheus.ValueType {
+	return prometheus.ValueType(*vt)
+}
+
+// MustNewConstMetric is a wrapper of prometheus.MustNewConstMetric
+func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
+	return prometheus.MustNewConstMetric(desc.toPrometheusDesc(), valueType.toPromValueType(), value, labelValues...)
+}