Turn of metrics for reflectors created by watch managers

pkg/kubelet/kubelet.go

@@ -544,6 +544,12 @@ func NewMainKubelet(kubeCfg *kubeletconfiginternal.KubeletConfiguration,
 		klet.cloudResourceSyncManager = cloudresource.NewSyncManager(klet.cloud, nodeName, klet.nodeStatusUpdateFrequency)
 	}
 
+	// Set the noop metrics provider for all reflectors that will be created
+	// after this point, so that watch-based managers (if used) will not
+	// blow the Kubelet memory usage if there are huge churn of secrets and/or
+	// configmaps attached to pods running on this node.
+	cache.SetReflectorMetricsProvider(manager.NoopMetricsProvider{})
+
 	var secretManager secret.Manager
 	var configMapManager configmap.Manager
 	switch kubeCfg.ConfigMapAndSecretChangeDetectionStrategy {

pkg/kubelet/util/manager/BUILD

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "cache_based_manager.go",
         "manager.go",
+        "noop_reflector_metrics.go",
         "watch_based_manager.go",
     ],
     importpath = "k8s.io/kubernetes/pkg/kubelet/util/manager",

pkg/kubelet/util/manager/noop_reflector_metrics.go

@@ -0,0 +1,57 @@
+/*
+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 manager
+
+import (
+	"k8s.io/client-go/tools/cache"
+)
+
+type noopMetric struct{}
+
+func (noopMetric) Inc()            {}
+func (noopMetric) Dec()            {}
+func (noopMetric) Observe(float64) {}
+func (noopMetric) Set(float64)     {}
+
+// NoopMetricsProvider implements interface of reflector metrics
+// by faking all the metrics.
+type NoopMetricsProvider struct{}
+
+func (NoopMetricsProvider) NewListsMetric(name string) cache.CounterMetric {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewListDurationMetric(name string) cache.SummaryMetric {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewItemsInListMetric(name string) cache.SummaryMetric   {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewWatchesMetric(name string) cache.CounterMetric       {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewShortWatchesMetric(name string) cache.CounterMetric  {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewWatchDurationMetric(name string) cache.SummaryMetric {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewItemsInWatchMetric(name string) cache.SummaryMetric  {
+	return noopMetric{}
+}
+func (NoopMetricsProvider) NewLastResourceVersionMetric(name string) cache.GaugeMetric {
+	return noopMetric{}
+}