Add RESTMapper to ControllerContext and make it generic for controllers

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

@@ -22,8 +22,6 @@ package app
 
 import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
-	"k8s.io/client-go/discovery"
-	discocache "k8s.io/client-go/discovery/cached"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/scale"
 	"k8s.io/kubernetes/pkg/controller/podautoscaler"
@@ -73,15 +71,10 @@ func startHPAControllerWithMetricsClient(ctx ControllerContext, metricsClient me
 	hpaClient := ctx.ClientBuilder.ClientOrDie("horizontal-pod-autoscaler")
 	hpaClientConfig := ctx.ClientBuilder.ConfigOrDie("horizontal-pod-autoscaler")
 
-	// TODO: we need something like deferred discovery REST mapper that calls invalidate
-	// on cache misses.
-	cachedDiscovery := discocache.NewMemCacheClient(hpaClientGoClient.Discovery())
-	restMapper := discovery.NewDeferredDiscoveryRESTMapper(cachedDiscovery)
-	restMapper.Reset()
 	// we don't use cached discovery because DiscoveryScaleKindResolver does its own caching,
 	// so we want to re-fetch every time when we actually ask for it
 	scaleKindResolver := scale.NewDiscoveryScaleKindResolver(hpaClientGoClient.Discovery())
-	scaleClient, err := scale.NewForConfig(hpaClientConfig, restMapper, dynamic.LegacyAPIPathResolverFunc, scaleKindResolver)
+	scaleClient, err := scale.NewForConfig(hpaClientConfig, ctx.RESTMapper, dynamic.LegacyAPIPathResolverFunc, scaleKindResolver)
 	if err != nil {
 		return false, err
 	}
@@ -95,7 +88,7 @@ func startHPAControllerWithMetricsClient(ctx ControllerContext, metricsClient me
 		hpaClientGoClient.CoreV1(),
 		scaleClient,
 		hpaClient.AutoscalingV1(),
-		restMapper,
+		ctx.RESTMapper,
 		replicaCalc,
 		ctx.InformerFactory.Autoscaling().V1().HorizontalPodAutoscalers(),
 		ctx.ComponentConfig.HPAController.HorizontalPodAutoscalerSyncPeriod.Duration,

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

@@ -35,6 +35,8 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/uuid"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/discovery"
+	cacheddiscovery "k8s.io/client-go/discovery/cached"
 	"k8s.io/client-go/informers"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/leaderelection"
@@ -223,6 +225,11 @@ type ControllerContext struct {
 	// ComponentConfig provides access to init options for a given controller
 	ComponentConfig componentconfig.KubeControllerManagerConfiguration
 
+	// DeferredDiscoveryRESTMapper is a RESTMapper that will defer
+	// initialization of the RESTMapper until the first mapping is
+	// requested.
+	RESTMapper *discovery.DeferredDiscoveryRESTMapper
+
 	// AvailableResources is a map listing currently available resources
 	AvailableResources map[schema.GroupVersionResource]bool
 
@@ -389,6 +396,14 @@ func CreateControllerContext(s *config.CompletedConfig, rootClientBuilder, clien
 		return ControllerContext{}, fmt.Errorf("failed to wait for apiserver being healthy: %v", err)
 	}
 
+	// Use a discovery client capable of being refreshed.
+	discoveryClient := rootClientBuilder.ClientOrDie("controller-discovery")
+	cachedClient := cacheddiscovery.NewMemCacheClient(discoveryClient.Discovery())
+	restMapper := discovery.NewDeferredDiscoveryRESTMapper(cachedClient)
+	go wait.Until(func() {
+		restMapper.Reset()
+	}, 30*time.Second, stop)
+
 	availableResources, err := GetAvailableResources(rootClientBuilder)
 	if err != nil {
 		return ControllerContext{}, err
@@ -404,6 +419,7 @@ func CreateControllerContext(s *config.CompletedConfig, rootClientBuilder, clien
 		ClientBuilder:      clientBuilder,
 		InformerFactory:    sharedInformers,
 		ComponentConfig:    s.Generic.ComponentConfig,
+		RESTMapper:         restMapper,
 		AvailableResources: availableResources,
 		Cloud:              cloud,
 		LoopMode:           loopMode,

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

@@ -31,7 +31,6 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
-	"k8s.io/client-go/discovery"
 	cacheddiscovery "k8s.io/client-go/discovery/cached"
 	"k8s.io/client-go/dynamic"
 	clientset "k8s.io/client-go/kubernetes"
@@ -300,13 +299,13 @@ func startNamespaceController(ctx ControllerContext) (bool, error) {
 	nsKubeconfig.Burst *= 100
 	namespaceKubeClient := clientset.NewForConfigOrDie(nsKubeconfig)
 
-	discoverResourcesFn := namespaceKubeClient.Discovery().ServerPreferredNamespacedResources
-
 	dynamicClient, err := dynamic.NewForConfig(nsKubeconfig)
 	if err != nil {
 		return true, err
 	}
 
+	discoverResourcesFn := namespaceKubeClient.Discovery().ServerPreferredNamespacedResources
+
 	namespaceController := namespacecontroller.NewNamespaceController(
 		namespaceKubeClient,
 		dynamicClient,
@@ -348,11 +347,7 @@ func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
 	}
 
 	gcClientset := ctx.ClientBuilder.ClientOrDie("generic-garbage-collector")
-
-	// Use a discovery client capable of being refreshed.
 	discoveryClient := cacheddiscovery.NewMemCacheClient(gcClientset.Discovery())
-	restMapper := discovery.NewDeferredDiscoveryRESTMapper(discoveryClient)
-	restMapper.Reset()
 
 	config := ctx.ClientBuilder.ConfigOrDie("generic-garbage-collector")
 	config.ContentConfig = dynamic.ContentConfig()
@@ -360,8 +355,8 @@ func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
 	// resource types. Otherwise we'll be storing full Unstructured data in our
 	// caches for custom resources. Consider porting it to work with
 	// metav1beta1.PartialObjectMetadata.
-	metaOnlyClientPool := dynamic.NewClientPool(config, restMapper, dynamic.LegacyAPIPathResolverFunc)
+	metaOnlyClientPool := dynamic.NewClientPool(config, ctx.RESTMapper, dynamic.LegacyAPIPathResolverFunc)
-	clientPool := dynamic.NewClientPool(config, restMapper, dynamic.LegacyAPIPathResolverFunc)
+	clientPool := dynamic.NewClientPool(config, ctx.RESTMapper, dynamic.LegacyAPIPathResolverFunc)
 
 	// Get an initial set of deletable resources to prime the garbage collector.
 	deletableResources := garbagecollector.GetDeletableResources(discoveryClient)
@@ -372,7 +367,7 @@ func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
 	garbageCollector, err := garbagecollector.NewGarbageCollector(
 		metaOnlyClientPool,
 		clientPool,
-		restMapper,
+		ctx.RESTMapper,
 		deletableResources,
 		ignoredResources,
 		ctx.InformerFactory,

test/integration/garbagecollector/garbage_collector_test.go

@@ -254,6 +254,12 @@ func setupWithServer(t *testing.T, result *kubeapiservertesting.TestServer, work
 	}
 	syncPeriod := 5 * time.Second
 	startGC := func(workers int) {
+		go wait.Until(func() {
+			// Resetting the REST mapper will also invalidate the underlying discovery
+			// client. This is a leaky abstraction and assumes behavior about the REST
+			// mapper, but we'll deal with it for now.
+			restMapper.Reset()
+		}, syncPeriod, stopCh)
 		go gc.Run(workers, stopCh)
 		go gc.Sync(clientSet.Discovery(), syncPeriod, stopCh)
 	}