Update to kube v1.17

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/k8s.io/component-base/metrics/gauge.go

@@ -0,0 +1,193 @@
+/*
+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/blang/semver"
+	"github.com/prometheus/client_golang/prometheus"
+
+	"k8s.io/component-base/version"
+)
+
+// Gauge is our internal representation for our wrapping struct around prometheus
+// gauges. kubeGauge implements both kubeCollector and KubeGauge.
+type Gauge struct {
+	GaugeMetric
+	*GaugeOpts
+	lazyMetric
+	selfCollector
+}
+
+// NewGauge returns an object which satisfies the kubeCollector and KubeGauge interfaces.
+// However, the object returned will not measure anything unless the collector is first
+// registered, since the metric is lazily instantiated.
+func NewGauge(opts *GaugeOpts) *Gauge {
+	opts.StabilityLevel.setDefaults()
+
+	kc := &Gauge{
+		GaugeOpts:  opts,
+		lazyMetric: lazyMetric{},
+	}
+	kc.setPrometheusGauge(noop)
+	kc.lazyInit(kc)
+	return kc
+}
+
+// setPrometheusGauge sets the underlying KubeGauge object, i.e. the thing that does the measurement.
+func (g *Gauge) setPrometheusGauge(gauge prometheus.Gauge) {
+	g.GaugeMetric = gauge
+	g.initSelfCollection(gauge)
+}
+
+// DeprecatedVersion returns a pointer to the Version or nil
+func (g *Gauge) DeprecatedVersion() *semver.Version {
+	return parseSemver(g.GaugeOpts.DeprecatedVersion)
+}
+
+// initializeMetric invocation creates the actual underlying Gauge. Until this method is called
+// the underlying gauge is a no-op.
+func (g *Gauge) initializeMetric() {
+	g.GaugeOpts.annotateStabilityLevel()
+	// this actually creates the underlying prometheus gauge.
+	g.setPrometheusGauge(prometheus.NewGauge(g.GaugeOpts.toPromGaugeOpts()))
+}
+
+// initializeDeprecatedMetric invocation creates the actual (but deprecated) Gauge. Until this method
+// is called the underlying gauge is a no-op.
+func (g *Gauge) initializeDeprecatedMetric() {
+	g.GaugeOpts.markDeprecated()
+	g.initializeMetric()
+}
+
+// GaugeVec is the internal representation of our wrapping struct around prometheus
+// gaugeVecs. kubeGaugeVec implements both kubeCollector and KubeGaugeVec.
+type GaugeVec struct {
+	*prometheus.GaugeVec
+	*GaugeOpts
+	lazyMetric
+	originalLabels []string
+}
+
+// NewGaugeVec returns an object which satisfies the kubeCollector and KubeGaugeVec interfaces.
+// However, the object returned will not measure anything unless the collector is first
+// registered, since the metric is lazily instantiated.
+func NewGaugeVec(opts *GaugeOpts, labels []string) *GaugeVec {
+	opts.StabilityLevel.setDefaults()
+
+	cv := &GaugeVec{
+		GaugeVec:       noopGaugeVec,
+		GaugeOpts:      opts,
+		originalLabels: labels,
+		lazyMetric:     lazyMetric{},
+	}
+	cv.lazyInit(cv)
+	return cv
+}
+
+// DeprecatedVersion returns a pointer to the Version or nil
+func (v *GaugeVec) DeprecatedVersion() *semver.Version {
+	return parseSemver(v.GaugeOpts.DeprecatedVersion)
+}
+
+// initializeMetric invocation creates the actual underlying GaugeVec. Until this method is called
+// the underlying gaugeVec is a no-op.
+func (v *GaugeVec) initializeMetric() {
+	v.GaugeOpts.annotateStabilityLevel()
+	v.GaugeVec = prometheus.NewGaugeVec(v.GaugeOpts.toPromGaugeOpts(), v.originalLabels)
+}
+
+// initializeDeprecatedMetric invocation creates the actual (but deprecated) GaugeVec. Until this method is called
+// the underlying gaugeVec is a no-op.
+func (v *GaugeVec) initializeDeprecatedMetric() {
+	v.GaugeOpts.markDeprecated()
+	v.initializeMetric()
+}
+
+// Default Prometheus behavior actually results in the creation of a new metric
+// if a metric with the unique label values is not found in the underlying stored metricMap.
+// This means  that if this function is called but the underlying metric is not registered
+// (which means it will never be exposed externally nor consumed), the metric will exist in memory
+// for perpetuity (i.e. throughout application lifecycle).
+//
+// For reference: https://github.com/prometheus/client_golang/blob/v0.9.2/prometheus/gauge.go#L190-L208
+
+// WithLabelValues returns the GaugeMetric for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new GaugeMetric is created IFF the gaugeVec
+// has been registered to a metrics registry.
+func (v *GaugeVec) WithLabelValues(lvs ...string) GaugeMetric {
+	if !v.IsCreated() {
+		return noop // return no-op gauge
+	}
+	return v.GaugeVec.WithLabelValues(lvs...)
+}
+
+// With returns the GaugeMetric for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new GaugeMetric is created IFF the gaugeVec has
+// been registered to a metrics registry.
+func (v *GaugeVec) With(labels map[string]string) GaugeMetric {
+	if !v.IsCreated() {
+		return noop // return no-op gauge
+	}
+	return v.GaugeVec.With(labels)
+}
+
+// Delete deletes the metric where the variable labels are the same as those
+// passed in as labels. It returns true if a metric was deleted.
+//
+// It is not an error if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc. However, such inconsistent Labels
+// can never match an actual metric, so the method will always return false in
+// that case.
+func (v *GaugeVec) Delete(labels map[string]string) bool {
+	if !v.IsCreated() {
+		return false // since we haven't created the metric, we haven't deleted a metric with the passed in values
+	}
+	return v.GaugeVec.Delete(labels)
+}
+
+// Reset deletes all metrics in this vector.
+func (v *GaugeVec) Reset() {
+	if !v.IsCreated() {
+		return
+	}
+
+	v.GaugeVec.Reset()
+}
+
+func newGaugeFunc(opts GaugeOpts, function func() float64, v semver.Version) GaugeFunc {
+	g := NewGauge(&opts)
+
+	if !g.Create(&v) {
+		return nil
+	}
+
+	return prometheus.NewGaugeFunc(g.GaugeOpts.toPromGaugeOpts(), function)
+}
+
+// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
+// value reported is determined by calling the given function from within the
+// Write method. Take into account that metric collection may happen
+// concurrently. If that results in concurrent calls to Write, like in the case
+// where a GaugeFunc is directly registered with Prometheus, the provided
+// function must be concurrency-safe.
+func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
+	v := parseVersion(version.Get())
+
+	return newGaugeFunc(opts, function, v)
+}