make it possible to allow discovery errors for controllers

cmd/kube-controller-manager/app/BUILD

@@ -111,6 +111,7 @@ go_library(
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/serializer:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/apiserver/pkg/server/healthz:go_default_library",

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

@@ -33,6 +33,7 @@ import (
 	"time"
 
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/wait"
 
@@ -366,7 +367,10 @@ func GetAvailableResources(clientBuilder controller.ControllerClientBuilder) (ma
 
 	resourceMap, err := discoveryClient.ServerResources()
 	if err != nil {
-		return nil, fmt.Errorf("failed to get supported resources from server: %v", err)
+		utilruntime.HandleError(fmt.Errorf("unable to get all supported resources from server: %v", err))
+	}
+	if len(resourceMap) == 0 {
+		return nil, fmt.Errorf("unable to get any supported resources from server")
 	}
 
 	allResources := map[schema.GroupVersionResource]bool{}

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

@@ -31,6 +31,7 @@ import (
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
@@ -303,7 +304,10 @@ func startGarbageCollectorController(ctx ControllerContext) (bool, error) {
 	gcClientset := ctx.ClientBuilder.ClientOrDie("generic-garbage-collector")
 	preferredResources, err := gcClientset.Discovery().ServerPreferredResources()
 	if err != nil {
-		return true, fmt.Errorf("failed to get supported resources from server: %v", err)
+		utilruntime.HandleError(fmt.Errorf("unable to get all supported resources from server: %v", err))
+	}
+	if len(preferredResources) == 0 {
+		return true, fmt.Errorf("unable to get any supported resources from server: %v", err)
 	}
 	deletableResources := discovery.FilteredBy(discovery.SupportsAllVerbs{Verbs: []string{"get", "list", "watch", "patch", "update", "delete"}}, preferredResources)
 	deletableGroupVersionResources, err := discovery.GroupVersionResources(deletableResources)

pkg/controller/namespace/deletion/BUILD

@@ -20,6 +20,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1/unstructured:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/runtime/schema:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/errors:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/client-go/discovery:go_default_library",
         "//vendor/k8s.io/client-go/dynamic:go_default_library",

pkg/controller/namespace/deletion/namespaced_resources_deleter.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
@@ -165,7 +166,10 @@ func (d *namespacedResourcesDeleter) initOpCache() {
 	// TODO(sttts): get rid of opCache and http 405 logic around it and trust discovery info
 	resources, err := d.discoverResourcesFn()
 	if err != nil {
-		glog.Fatalf("Failed to get supported resources: %v", err)
+		utilruntime.HandleError(fmt.Errorf("unable to get all supported resources from server: %v", err))
+	}
+	if len(resources) == 0 {
+		glog.Fatalf("Unable to get any supported resources from server: %v", err)
 	}
 	deletableGroupVersionResources := []schema.GroupVersionResource{}
 	for _, rl := range resources {

staging/src/k8s.io/client-go/discovery/discovery_client.go

@@ -187,7 +187,7 @@ func (d *DiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (r
 }
 
 // serverResources returns the supported resources for all groups and versions.
-func (d *DiscoveryClient) serverResources(failEarly bool) ([]*metav1.APIResourceList, error) {
+func (d *DiscoveryClient) serverResources() ([]*metav1.APIResourceList, error) {
 	apiGroups, err := d.ServerGroups()
 	if err != nil {
 		return nil, err
@@ -203,9 +203,6 @@ func (d *DiscoveryClient) serverResources(failEarly bool) ([]*metav1.APIResource
 			if err != nil {
 				// TODO: maybe restrict this to NotFound errors
 				failedGroups[gv] = err
-				if failEarly {
-					return nil, &ErrGroupDiscoveryFailed{Groups: failedGroups}
-				}
 				continue
 			}
 
@@ -249,7 +246,7 @@ func IsGroupDiscoveryFailedError(err error) bool {
 }
 
 // serverPreferredResources returns the supported resources with the version preferred by the server.
-func (d *DiscoveryClient) serverPreferredResources(failEarly bool) ([]*metav1.APIResourceList, error) {
+func (d *DiscoveryClient) serverPreferredResources() ([]*metav1.APIResourceList, error) {
 	serverGroupList, err := d.ServerGroups()
 	if err != nil {
 		return nil, err
@@ -269,9 +266,6 @@ func (d *DiscoveryClient) serverPreferredResources(failEarly bool) ([]*metav1.AP
 			if err != nil {
 				// TODO: maybe restrict this to NotFound errors
 				failedGroups[groupVersion] = err
-				if failEarly {
-					return nil, &ErrGroupDiscoveryFailed{Groups: failedGroups}
-				}
 				continue
 			}
 
@@ -316,9 +310,7 @@ func (d *DiscoveryClient) serverPreferredResources(failEarly bool) ([]*metav1.AP
 // ServerPreferredResources returns the supported resources with the version preferred by the
 // server.
 func (d *DiscoveryClient) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
-	return withRetries(defaultRetries, func(retryEarly bool) ([]*metav1.APIResourceList, error) {
+	return withRetries(defaultRetries, d.serverPreferredResources)
-		return d.serverPreferredResources(retryEarly)
-	})
 }
 
 // ServerPreferredNamespacedResources returns the supported namespaced resources with the
@@ -394,12 +386,11 @@ func (d *DiscoveryClient) OpenAPISchema() (*openapi_v2.Document, error) {
 }
 
 // withRetries retries the given recovery function in case the groups supported by the server change after ServerGroup() returns.
-func withRetries(maxRetries int, f func(failEarly bool) ([]*metav1.APIResourceList, error)) ([]*metav1.APIResourceList, error) {
+func withRetries(maxRetries int, f func() ([]*metav1.APIResourceList, error)) ([]*metav1.APIResourceList, error) {
 	var result []*metav1.APIResourceList
 	var err error
 	for i := 0; i < maxRetries; i++ {
-		failEarly := i < maxRetries-1
+		result, err = f()
-		result, err = f(failEarly)
 		if err == nil {
 			return result, nil
 		}