authorizer/webhook: make webhook authorizer cluster aware

pkg/kubeapiserver/authorizer/config.go

@@ -116,6 +116,7 @@ func (config Config) New() (authorizer.Authorizer, authorizer.RuleResolver, erro
 			}
 			webhookAuthorizer, err := webhook.New(config.WebhookConfigFile,
 				config.WebhookVersion,
+				"",
 				config.WebhookCacheAuthorizedTTL,
 				config.WebhookCacheUnauthorizedTTL,
 				*config.WebhookRetryBackoff,

staging/src/k8s.io/apiserver/pkg/authorization/authorizerfactory/delegating.go

@@ -42,6 +42,9 @@ type DelegatingAuthorizerConfig struct {
 	// This allows us to configure the sleep time at each iteration and the maximum number of retries allowed
 	// before we fail the webhook call in order to limit the fan out that ensues when the system is degraded.
 	WebhookRetryBackoff *wait.Backoff
+
+	// The cluster to execute authorization decisions against (optional).
+	Cluster string
 }
 
 func (c DelegatingAuthorizerConfig) New() (authorizer.Authorizer, error) {
@@ -58,5 +61,6 @@ func (c DelegatingAuthorizerConfig) New() (authorizer.Authorizer, error) {
 			RecordRequestTotal:   RecordRequestTotal,
 			RecordRequestLatency: RecordRequestLatency,
 		},
+		c.Cluster,
 	)
 }

staging/src/k8s.io/apiserver/plugin/pkg/authorizer/webhook/webhook.go

@@ -67,11 +67,12 @@ type WebhookAuthorizer struct {
 	retryBackoff        wait.Backoff
 	decisionOnError     authorizer.Decision
 	metrics             AuthorizerMetrics
+	cluster             string
 }
 
 // NewFromInterface creates a WebhookAuthorizer using the given subjectAccessReview client
-func NewFromInterface(subjectAccessReview authorizationv1client.AuthorizationV1Interface, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, metrics AuthorizerMetrics) (*WebhookAuthorizer, error) {
-	return newWithBackoff(&subjectAccessReviewV1Client{subjectAccessReview.RESTClient()}, authorizedTTL, unauthorizedTTL, retryBackoff, metrics)
+func NewFromInterface(subjectAccessReview authorizationv1client.AuthorizationV1Interface, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, metrics AuthorizerMetrics, cluster string) (*WebhookAuthorizer, error) {
+	return newWithBackoff(&subjectAccessReviewV1Client{subjectAccessReview.RESTClient(), cluster}, authorizedTTL, unauthorizedTTL, retryBackoff, metrics, cluster)
 }
 
 // New creates a new WebhookAuthorizer from the provided kubeconfig file.
@@ -93,19 +94,19 @@ func NewFromInterface(subjectAccessReview authorizationv1client.AuthorizationV1I
 //
 // For additional HTTP configuration, refer to the kubeconfig documentation
 // https://kubernetes.io/docs/user-guide/kubeconfig-file/.
-func New(kubeConfigFile string, version string, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, customDial utilnet.DialFunc) (*WebhookAuthorizer, error) {
-	subjectAccessReview, err := subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile, version, retryBackoff, customDial)
+func New(kubeConfigFile, version, cluster string, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, customDial utilnet.DialFunc) (*WebhookAuthorizer, error) {
+	subjectAccessReview, err := subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile, version, cluster, retryBackoff, customDial)
 	if err != nil {
 		return nil, err
 	}
 	return newWithBackoff(subjectAccessReview, authorizedTTL, unauthorizedTTL, retryBackoff, AuthorizerMetrics{
 		RecordRequestTotal:   noopMetrics{}.RecordRequestTotal,
 		RecordRequestLatency: noopMetrics{}.RecordRequestLatency,
-	})
+	}, cluster)
 }
 
 // newWithBackoff allows tests to skip the sleep.
-func newWithBackoff(subjectAccessReview subjectAccessReviewer, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, metrics AuthorizerMetrics) (*WebhookAuthorizer, error) {
+func newWithBackoff(subjectAccessReview subjectAccessReviewer, authorizedTTL, unauthorizedTTL time.Duration, retryBackoff wait.Backoff, metrics AuthorizerMetrics, cluster string) (*WebhookAuthorizer, error) {
 	return &WebhookAuthorizer{
 		subjectAccessReview: subjectAccessReview,
 		responseCache:       cache.NewLRUExpireCache(8192),
@@ -114,6 +115,7 @@ func newWithBackoff(subjectAccessReview subjectAccessReviewer, authorizedTTL, un
 		retryBackoff:        retryBackoff,
 		decisionOnError:     authorizer.DecisionNoOpinion,
 		metrics:             metrics,
+		cluster:             cluster,
 	}, nil
 }
 
@@ -272,7 +274,7 @@ func convertToSARExtra(extra map[string][]string) map[string]authorizationv1.Ext
 // subjectAccessReviewInterfaceFromKubeconfig builds a client from the specified kubeconfig file,
 // and returns a SubjectAccessReviewInterface that uses that client. Note that the client submits SubjectAccessReview
 // requests to the exact path specified in the kubeconfig file, so arbitrary non-API servers can be targeted.
-func subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile string, version string, retryBackoff wait.Backoff, customDial utilnet.DialFunc) (subjectAccessReviewer, error) {
+func subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile, version, cluster string, retryBackoff wait.Backoff, customDial utilnet.DialFunc) (subjectAccessReviewer, error) {
 	localScheme := runtime.NewScheme()
 	if err := scheme.AddToScheme(localScheme); err != nil {
 		return nil, err
@@ -288,7 +290,7 @@ func subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile string, version s
 		if err != nil {
 			return nil, err
 		}
-		return &subjectAccessReviewV1ClientGW{gw.RestClient}, nil
+		return &subjectAccessReviewV1ClientGW{gw.RestClient, cluster}, nil
 
 	case authorizationv1beta1.SchemeGroupVersion.Version:
 		groupVersions := []schema.GroupVersion{authorizationv1beta1.SchemeGroupVersion}
@@ -299,7 +301,7 @@ func subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile string, version s
 		if err != nil {
 			return nil, err
 		}
-		return &subjectAccessReviewV1beta1ClientGW{gw.RestClient}, nil
+		return &subjectAccessReviewV1beta1ClientGW{gw.RestClient, cluster}, nil
 
 	default:
 		return nil, fmt.Errorf(
@@ -312,13 +314,15 @@ func subjectAccessReviewInterfaceFromKubeconfig(kubeConfigFile string, version s
 }
 
 type subjectAccessReviewV1Client struct {
-	client rest.Interface
+	client  rest.Interface
+	cluster string
 }
 
 func (t *subjectAccessReviewV1Client) Create(ctx context.Context, subjectAccessReview *authorizationv1.SubjectAccessReview, opts metav1.CreateOptions) (result *authorizationv1.SubjectAccessReview, statusCode int, err error) {
 	result = &authorizationv1.SubjectAccessReview{}
 
 	restResult := t.client.Post().
+		Cluster(t.cluster).
 		Resource("subjectaccessreviews").
 		VersionedParams(&opts, scheme.ParameterCodec).
 		Body(subjectAccessReview).
@@ -331,14 +335,15 @@ func (t *subjectAccessReviewV1Client) Create(ctx context.Context, subjectAccessR
 
 // subjectAccessReviewV1ClientGW used by the generic webhook, doesn't specify GVR.
 type subjectAccessReviewV1ClientGW struct {
-	client rest.Interface
+	client  rest.Interface
+	cluster string
 }
 
 func (t *subjectAccessReviewV1ClientGW) Create(ctx context.Context, subjectAccessReview *authorizationv1.SubjectAccessReview, _ metav1.CreateOptions) (*authorizationv1.SubjectAccessReview, int, error) {
 	var statusCode int
 	result := &authorizationv1.SubjectAccessReview{}
 
-	restResult := t.client.Post().Body(subjectAccessReview).Do(ctx)
+	restResult := t.client.Post().Cluster(t.cluster).Body(subjectAccessReview).Do(ctx)
 
 	restResult.StatusCode(&statusCode)
 	err := restResult.Into(result)
@@ -348,15 +353,16 @@ func (t *subjectAccessReviewV1ClientGW) Create(ctx context.Context, subjectAcces
 
 // subjectAccessReviewV1beta1ClientGW used by the generic webhook, doesn't specify GVR.
 type subjectAccessReviewV1beta1ClientGW struct {
-	client rest.Interface
+	client  rest.Interface
+	cluster string
 }
 
 func (t *subjectAccessReviewV1beta1ClientGW) Create(ctx context.Context, subjectAccessReview *authorizationv1.SubjectAccessReview, _ metav1.CreateOptions) (*authorizationv1.SubjectAccessReview, int, error) {
 	var statusCode int
 	v1beta1Review := &authorizationv1beta1.SubjectAccessReview{Spec: v1SpecToV1beta1Spec(&subjectAccessReview.Spec)}
 	v1beta1Result := &authorizationv1beta1.SubjectAccessReview{}
 
-	restResult := t.client.Post().Body(v1beta1Review).Do(ctx)
+	restResult := t.client.Post().Cluster(t.cluster).Body(v1beta1Review).Do(ctx)
 
 	restResult.StatusCode(&statusCode)
 	err := restResult.Into(v1beta1Result)

staging/src/k8s.io/apiserver/plugin/pkg/authorizer/webhook/webhook_v1_test.go

@@ -194,11 +194,11 @@ current-context: default
 				return fmt.Errorf("failed to execute test template: %v", err)
 			}
 			// Create a new authorizer
-			sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1", testRetryBackoff, nil)
+			sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1", "", testRetryBackoff, nil)
 			if err != nil {
 				return fmt.Errorf("error building sar client: %v", err)
 			}
-			_, err = newWithBackoff(sarClient, 0, 0, testRetryBackoff, noopAuthorizerMetrics())
+			_, err = newWithBackoff(sarClient, 0, 0, testRetryBackoff, noopAuthorizerMetrics(), "")
 			return err
 		}()
 		if err != nil && !tt.wantErr {
@@ -333,11 +333,11 @@ func newV1Authorizer(callbackURL string, clientCert, clientKey, ca []byte, cache
 	if err := json.NewEncoder(tempfile).Encode(config); err != nil {
 		return nil, err
 	}
-	sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1", testRetryBackoff, nil)
+	sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1", "", testRetryBackoff, nil)
 	if err != nil {
 		return nil, fmt.Errorf("error building sar client: %v", err)
 	}
-	return newWithBackoff(sarClient, cacheTime, cacheTime, testRetryBackoff, metrics)
+	return newWithBackoff(sarClient, cacheTime, cacheTime, testRetryBackoff, metrics, "")
 }
 
 func TestV1TLSConfig(t *testing.T) {

staging/src/k8s.io/apiserver/plugin/pkg/authorizer/webhook/webhook_v1beta1_test.go

@@ -186,11 +186,11 @@ current-context: default
 				return fmt.Errorf("failed to execute test template: %v", err)
 			}
 			// Create a new authorizer
-			sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1beta1", testRetryBackoff, nil)
+			sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1beta1", "", testRetryBackoff, nil)
 			if err != nil {
 				return fmt.Errorf("error building sar client: %v", err)
 			}
-			_, err = newWithBackoff(sarClient, 0, 0, testRetryBackoff, noopAuthorizerMetrics())
+			_, err = newWithBackoff(sarClient, 0, 0, testRetryBackoff, noopAuthorizerMetrics(), "")
 			return err
 		}()
 		if err != nil && !tt.wantErr {
@@ -325,11 +325,11 @@ func newV1beta1Authorizer(callbackURL string, clientCert, clientKey, ca []byte,
 	if err := json.NewEncoder(tempfile).Encode(config); err != nil {
 		return nil, err
 	}
-	sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1beta1", testRetryBackoff, nil)
+	sarClient, err := subjectAccessReviewInterfaceFromKubeconfig(p, "v1beta1", "", testRetryBackoff, nil)
 	if err != nil {
 		return nil, fmt.Errorf("error building sar client: %v", err)
 	}
-	return newWithBackoff(sarClient, cacheTime, cacheTime, testRetryBackoff, noopAuthorizerMetrics())
+	return newWithBackoff(sarClient, cacheTime, cacheTime, testRetryBackoff, noopAuthorizerMetrics(), "")
 }
 
 func TestV1beta1TLSConfig(t *testing.T) {