make using service account credentials from controllers optional

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

@@ -167,7 +167,7 @@ func Run(s *options.CMServer) error {
 			ClientConfig: kubeconfig,
 		}
 		var clientBuilder controller.ControllerClientBuilder
-		if len(s.ServiceAccountKeyFile) > 0 {
+		if len(s.ServiceAccountKeyFile) > 0 && s.UseServiceAccountCredentials {
 			clientBuilder = controller.SAControllerClientBuilder{
 				ClientConfig: restclient.AnonymousClientConfig(kubeconfig),
 				CoreClient:   kubeClient.Core(),

cmd/kube-controller-manager/app/options/options.go

@@ -105,6 +105,7 @@ func NewCMServer() *CMServer {
 func (s *CMServer) AddFlags(fs *pflag.FlagSet) {
 	fs.Int32Var(&s.Port, "port", s.Port, "The port that the controller-manager's http service runs on")
 	fs.Var(componentconfig.IPVar{Val: &s.Address}, "address", "The IP address to serve on (set to 0.0.0.0 for all interfaces)")
+	fs.BoolVar(&s.UseServiceAccountCredentials, "use-service-account-credentials", s.UseServiceAccountCredentials, "If true, use individual service account credentials for each controller.")
 	fs.StringVar(&s.CloudProvider, "cloud-provider", s.CloudProvider, "The provider for cloud services.  Empty string for no provider.")
 	fs.StringVar(&s.CloudConfigFile, "cloud-config", s.CloudConfigFile, "The path to the cloud provider configuration file.  Empty string for no configuration file.")
 	fs.Int32Var(&s.ConcurrentEndpointSyncs, "concurrent-endpoint-syncs", s.ConcurrentEndpointSyncs, "The number of endpoint syncing operations that will be done concurrently. Larger number = faster endpoint updating, but more CPU (and network) load")

hack/verify-flags/known-flags.txt

@@ -573,6 +573,7 @@ unix-socket
 update-period
 upgrade-image
 upgrade-target
+use-service-account-credentials
 use-kubernetes-cluster-service
 use-kubernetes-version
 user-whitelist

pkg/apis/componentconfig/types.go

@@ -586,6 +586,9 @@ type KubeControllerManagerConfiguration struct {
 	Port int32 `json:"port"`
 	// address is the IP address to serve on (set to 0.0.0.0 for all interfaces).
 	Address string `json:"address"`
+	// useServiceAccountCredentials indicates whether controllers should be run with
+	// individual service account credentials.
+	UseServiceAccountCredentials bool `json:"useServiceAccountCredentials"`
 	// cloudProvider is the provider for cloud services.
 	CloudProvider string `json:"cloudProvider"`
 	// cloudConfigFile is the path to the cloud provider configuration file.

pkg/apis/componentconfig/zz_generated.deepcopy.go

@@ -75,6 +75,7 @@ func DeepCopy_componentconfig_KubeControllerManagerConfiguration(in interface{},
 		out.TypeMeta = in.TypeMeta
 		out.Port = in.Port
 		out.Address = in.Address
+		out.UseServiceAccountCredentials = in.UseServiceAccountCredentials
 		out.CloudProvider = in.CloudProvider
 		out.CloudConfigFile = in.CloudConfigFile
 		out.ConcurrentEndpointSyncs = in.ConcurrentEndpointSyncs

pkg/generated/openapi/zz_generated.openapi.go

@@ -1471,6 +1471,13 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 							Format:      "",
 						},
 					},
+					"useServiceAccountCredentials": {
+						SchemaProps: spec.SchemaProps{
+							Description: "useServiceAccountCredentials indicates whether controllers should be run with individual service account credentials.",
+							Type:        []string{"boolean"},
+							Format:      "",
+						},
+					},
 					"cloudProvider": {
 						SchemaProps: spec.SchemaProps{
 							Description: "cloudProvider is the provider for cloud services.",
@@ -1848,7 +1855,7 @@ var OpenAPIDefinitions *common.OpenAPIDefinitions = &common.OpenAPIDefinitions{
 						},
 					},
 				},
-				Required: []string{"TypeMeta", "port", "address", "cloudProvider", "cloudConfigFile", "concurrentEndpointSyncs", "concurrentRSSyncs", "concurrentRCSyncs", "concurrentServiceSyncs", "concurrentResourceQuotaSyncs", "concurrentDeploymentSyncs", "concurrentDaemonSetSyncs", "concurrentJobSyncs", "concurrentNamespaceSyncs", "concurrentSATokenSyncs", "lookupCacheSizeForRC", "lookupCacheSizeForRS", "lookupCacheSizeForDaemonSet", "serviceSyncPeriod", "nodeSyncPeriod", "routeReconciliationPeriod", "resourceQuotaSyncPeriod", "namespaceSyncPeriod", "pvClaimBinderSyncPeriod", "minResyncPeriod", "terminatedPodGCThreshold", "horizontalPodAutoscalerSyncPeriod", "deploymentControllerSyncPeriod", "podEvictionTimeout", "deletingPodsQps", "deletingPodsBurst", "nodeMonitorGracePeriod", "registerRetryCount", "nodeStartupGracePeriod", "nodeMonitorPeriod", "serviceAccountKeyFile", "clusterSigningCertFile", "clusterSigningKeyFile", "approveAllKubeletCSRsForGroup", "enableProfiling", "clusterName", "clusterCIDR", "serviceCIDR", "nodeCIDRMaskSize", "allocateNodeCIDRs", "configureCloudRoutes", "rootCAFile", "contentType", "kubeAPIQPS", "kubeAPIBurst", "leaderElection", "volumeConfiguration", "controllerStartInterval", "enableGarbageCollector", "concurrentGCSyncs", "nodeEvictionRate", "secondaryNodeEvictionRate", "largeClusterSizeThreshold", "unhealthyZoneThreshold"},
+				Required: []string{"TypeMeta", "port", "address", "useServiceAccountCredentials", "cloudProvider", "cloudConfigFile", "concurrentEndpointSyncs", "concurrentRSSyncs", "concurrentRCSyncs", "concurrentServiceSyncs", "concurrentResourceQuotaSyncs", "concurrentDeploymentSyncs", "concurrentDaemonSetSyncs", "concurrentJobSyncs", "concurrentNamespaceSyncs", "concurrentSATokenSyncs", "lookupCacheSizeForRC", "lookupCacheSizeForRS", "lookupCacheSizeForDaemonSet", "serviceSyncPeriod", "nodeSyncPeriod", "routeReconciliationPeriod", "resourceQuotaSyncPeriod", "namespaceSyncPeriod", "pvClaimBinderSyncPeriod", "minResyncPeriod", "terminatedPodGCThreshold", "horizontalPodAutoscalerSyncPeriod", "deploymentControllerSyncPeriod", "podEvictionTimeout", "deletingPodsQps", "deletingPodsBurst", "nodeMonitorGracePeriod", "registerRetryCount", "nodeStartupGracePeriod", "nodeMonitorPeriod", "serviceAccountKeyFile", "clusterSigningCertFile", "clusterSigningKeyFile", "approveAllKubeletCSRsForGroup", "enableProfiling", "clusterName", "clusterCIDR", "serviceCIDR", "nodeCIDRMaskSize", "allocateNodeCIDRs", "configureCloudRoutes", "rootCAFile", "contentType", "kubeAPIQPS", "kubeAPIBurst", "leaderElection", "volumeConfiguration", "controllerStartInterval", "enableGarbageCollector", "concurrentGCSyncs", "nodeEvictionRate", "secondaryNodeEvictionRate", "largeClusterSizeThreshold", "unhealthyZoneThreshold"},
 			},
 		},
 		Dependencies: []string{