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/prometheus/ratelimiter/OWNERS

@@ -1,9 +0,0 @@
-# See the OWNERS docs at https://go.k8s.io/owners
-
-approvers:
-- sig-instrumentation-approvers
-- logicalhan
-reviewers:
-- sig-instrumentation-reviewers
-labels:
-- sig/instrumentation

vendor/k8s.io/component-base/metrics/prometheus/ratelimiter/rate_limiter.go

@@ -1,77 +0,0 @@
-/*
-Copyright 2015 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 ratelimiter
-
-import (
-	"fmt"
-	"sync"
-
-	"k8s.io/client-go/util/flowcontrol"
-	"k8s.io/component-base/metrics"
-	"k8s.io/component-base/metrics/legacyregistry"
-)
-
-var (
-	metricsLock        sync.Mutex
-	rateLimiterMetrics = make(map[string]*rateLimiterMetric)
-)
-
-type rateLimiterMetric struct {
-	metric metrics.GaugeMetric
-	stopCh chan struct{}
-}
-
-func registerRateLimiterMetric(ownerName string) error {
-	metricsLock.Lock()
-	defer metricsLock.Unlock()
-
-	if _, ok := rateLimiterMetrics[ownerName]; ok {
-		// only register once in Prometheus. We happen to see an ownerName reused in parallel integration tests.
-		return nil
-	}
-	metric := metrics.NewGauge(&metrics.GaugeOpts{
-		Name:           "rate_limiter_use",
-		Subsystem:      ownerName,
-		Help:           fmt.Sprintf("A metric measuring the saturation of the rate limiter for %v", ownerName),
-		StabilityLevel: metrics.ALPHA,
-	})
-	if err := legacyregistry.Register(metric); err != nil {
-		return fmt.Errorf("error registering rate limiter usage metric: %v", err)
-	}
-	stopCh := make(chan struct{})
-	rateLimiterMetrics[ownerName] = &rateLimiterMetric{
-		metric: metric,
-		stopCh: stopCh,
-	}
-	return nil
-}
-
-// RegisterMetricAndTrackRateLimiterUsage registers a metric ownerName_rate_limiter_use in prometheus to track
-// how much used rateLimiter is and starts a goroutine that updates this metric every updatePeriod
-func RegisterMetricAndTrackRateLimiterUsage(ownerName string, rateLimiter flowcontrol.RateLimiter) error {
-	if err := registerRateLimiterMetric(ownerName); err != nil {
-		return err
-	}
-	// TODO: determine how to track rate limiter saturation
-	// See discussion at https://go-review.googlesource.com/c/time/+/29958#message-4caffc11669cadd90e2da4c05122cfec50ea6a22
-	// go wait.Until(func() {
-	//   metricsLock.Lock()
-	//   defer metricsLock.Unlock()
-	//   rateLimiterMetrics[ownerName].metric.Set()
-	// }, updatePeriod, rateLimiterMetrics[ownerName].stopCh)
-	return nil
-}