kubecontrollermanager

cmd\kube-controller-manager\controller-manager.go

func main() {
	command := app.NewControllerManagerCommand() --->cmd\kube-controller-manager\app\controllermanager.go
	code := cli.Run(command)
	os.Exit(code)
}

cmd\kube-controller-manager\app\controllermanager.go

NewControllerManagerCommand
	cmd := &cobra.Command{
		Run: func(cmd *cobra.Command, args []string) {
			c, err := s.Config(KnownControllers(), ControllersDisabledByDefault.List())
			if err := Run(c.Complete(), wait.NeverStop); err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				os.Exit(1)
			}
		}


Run
	run := func(ctx context.Context, startSATokenController InitFunc, initializersFunc ControllerInitializersFunc) {

		controllerContext, err := CreateControllerContext(c, rootClientBuilder, clientBuilder, ctx.Done())
		if err != nil {
			klog.Fatalf("error building controller context: %v", err)
		}
		controllerInitializers := initializersFunc(controllerContext.LoopMode) --->ControllerInitializersFunc --->NewControllerInitializers
		if err := StartControllers(ctx, controllerContext, startSATokenController, controllerInitializers, unsecuredMux, healthzHandler); err != nil {
			klog.Fatalf("error starting controllers: %v", err)
		}

		controllerContext.InformerFactory.Start(stopCh)
		controllerContext.ObjectOrMetadataInformerFactory.Start(stopCh)
		close(controllerContext.InformersStarted)

		select {}
	}
	...
	// 没开选举直接开跑
	if !c.ComponentConfig.Generic.LeaderElection.LeaderElect {
		run(context.TODO(), saTokenControllerInitFunc, NewControllerInitializers)
		panic("unreachable")
	}
	...
	// 以主机名+随机字符串为id进行参选
	id, err := os.Hostname()
	id = id + "_" + string(uuid.NewUUID())
	...
	go leaderElectAndRun(c, id, electionChecker,
		c.ComponentConfig.Generic.LeaderElection.ResourceLock,
		c.ComponentConfig.Generic.LeaderElection.ResourceName,
		leaderelection.LeaderCallbacks{
			OnStartedLeading: func(ctx context.Context) {
				initializersFunc := NewControllerInitializers
				if leaderMigrator != nil {
					// If leader migration is enabled, we should start only non-migrated controllers
					//  for the main lock.
					initializersFunc = createInitializersFunc(leaderMigrator.FilterFunc, leadermigration.ControllerNonMigrated)
					klog.Info("leader migration: starting main controllers.")
				}
				// 竞选成功则开启主控制器
				run(ctx, startSATokenController, initializersFunc)
			},
			OnStoppedLeading: func() {
				// 失败则结束
				klog.Fatalf("leaderelection lost")
			},
		})
		...
		go leaderElectAndRun(c, id, electionChecker,
			c.ComponentConfig.Generic.LeaderMigration.ResourceLock,
			c.ComponentConfig.Generic.LeaderMigration.LeaderName,
			leaderelection.LeaderCallbacks{
				OnStartedLeading: func(ctx context.Context) {
					klog.Info("leader migration: starting migrated controllers.")
					// DO NOT start saTokenController under migration lock
					run(ctx, nil, createInitializersFunc(leaderMigrator.FilterFunc, leadermigration.ControllerMigrated))
				},
				OnStoppedLeading: func() {
					klog.Fatalf("migration leaderelection lost")
				},
			})

**// 内置默认的所有控制器**
// 共38个，其中4个有条件开启，34个默认开启
// 所有控制器开启逻辑代码都在cmd\kube-controller-manager\app\core.go，一一对应，主体逻辑相同，开goroutine无限loop自己关注的资源对象进行相应动作
func NewControllerInitializers(loopMode ControllerLoopMode) map[string]InitFunc {
	controllers := map[string]InitFunc{}
	controllers["endpoint"] = startEndpointController
	controllers["endpointslice"] = startEndpointSliceController
	controllers["endpointslicemirroring"] = startEndpointSliceMirroringController
	controllers["replicationcontroller"] = startReplicationController
	controllers["podgc"] = startPodGCController
	controllers["resourcequota"] = startResourceQuotaController
	controllers["namespace"] = startNamespaceController --->cmd\kube-controller-manager\app\core.go
	controllers["serviceaccount"] = startServiceAccountController
	controllers["garbagecollector"] = startGarbageCollectorController
	controllers["daemonset"] = startDaemonSetController
	controllers["job"] = startJobController
	controllers["deployment"] = startDeploymentController
	controllers["replicaset"] = startReplicaSetController
	controllers["horizontalpodautoscaling"] = startHPAController
	controllers["disruption"] = startDisruptionController
	controllers["statefulset"] = startStatefulSetController
	controllers["cronjob"] = startCronJobController
	controllers["csrsigning"] = startCSRSigningController
	controllers["csrapproving"] = startCSRApprovingController
	controllers["csrcleaner"] = startCSRCleanerController
	controllers["ttl"] = startTTLController
	controllers["bootstrapsigner"] = startBootstrapSignerController
	controllers["tokencleaner"] = startTokenCleanerController
	controllers["nodeipam"] = startNodeIpamController
	controllers["nodelifecycle"] = startNodeLifecycleController
	if loopMode == IncludeCloudLoops {
		controllers["service"] = startServiceController
		controllers["route"] = startRouteController
		controllers["cloud-node-lifecycle"] = startCloudNodeLifecycleController
		// TODO: volume controller into the IncludeCloudLoops only set.
	}
	controllers["persistentvolume-binder"] = startPersistentVolumeBinderController
	controllers["attachdetach"] = startAttachDetachController
	controllers["persistentvolume-expander"] = startVolumeExpandController
	controllers["clusterrole-aggregation"] = startClusterRoleAggregrationController
	controllers["pvc-protection"] = startPVCProtectionController
	controllers["pv-protection"] = startPVProtectionController
	controllers["ttl-after-finished"] = startTTLAfterFinishedController
	controllers["root-ca-cert-publisher"] = startRootCACertPublisher
	controllers["ephemeral-volume"] = startEphemeralVolumeController
	if utilfeature.DefaultFeatureGate.Enabled(genericfeatures.APIServerIdentity) &&
		utilfeature.DefaultFeatureGate.Enabled(genericfeatures.StorageVersionAPI) {
		controllers["storage-version-gc"] = startStorageVersionGCController
	}

	return controllers
}