rebase: update kubernetes to v1.20.0

updated kubernetes packages to latest
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

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

@@ -0,0 +1,79 @@
+/*
+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 (
+	"fmt"
+
+	"github.com/blang/semver"
+	"github.com/spf13/pflag"
+
+	"k8s.io/component-base/version"
+)
+
+// Options has all parameters needed for exposing metrics from components
+type Options struct {
+	ShowHiddenMetricsForVersion string
+}
+
+// NewOptions returns default metrics options
+func NewOptions() *Options {
+	return &Options{}
+}
+
+// Validate validates metrics flags options.
+func (o *Options) Validate() []error {
+	err := validateShowHiddenMetricsVersion(parseVersion(version.Get()), o.ShowHiddenMetricsForVersion)
+	if err != nil {
+		return []error{err}
+	}
+
+	return nil
+}
+
+// AddFlags adds flags for exposing component metrics.
+func (o *Options) AddFlags(fs *pflag.FlagSet) {
+	if o != nil {
+		o = NewOptions()
+	}
+	fs.StringVar(&o.ShowHiddenMetricsForVersion, "show-hidden-metrics-for-version", o.ShowHiddenMetricsForVersion,
+		"The previous version for which you want to show hidden metrics. "+
+			"Only the previous minor version is meaningful, other values will not be allowed. "+
+			"The format is <major>.<minor>, e.g.: '1.16'. "+
+			"The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics, "+
+			"rather than being surprised when they are permanently removed in the release after that.")
+}
+
+// Apply applies parameters into global configuration of metrics.
+func (o *Options) Apply() {
+	if o != nil && len(o.ShowHiddenMetricsForVersion) > 0 {
+		SetShowHidden()
+	}
+}
+
+func validateShowHiddenMetricsVersion(currentVersion semver.Version, targetVersionStr string) error {
+	if targetVersionStr == "" {
+		return nil
+	}
+
+	validVersionStr := fmt.Sprintf("%d.%d", currentVersion.Major, currentVersion.Minor-1)
+	if targetVersionStr != validVersionStr {
+		return fmt.Errorf("--show-hidden-metrics-for-version must be omitted or have the value '%v'. Only the previous minor version is allowed", validVersionStr)
+	}
+
+	return nil
+}