add FirstHitRESTMapper for adding thirdparty resources

pkg/api/meta/firsthit_restmapper.go

+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package meta
+
+import (
+	"fmt"
+
+	"k8s.io/kubernetes/pkg/api/unversioned"
+	utilerrors "k8s.io/kubernetes/pkg/util/errors"
+)
+
+// FirstHitRESTMapper is a wrapper for multiple RESTMappers which returns the
+// first successful result for the singular requests
+type FirstHitRESTMapper struct {
+	MultiRESTMapper
+}
+
+func (m FirstHitRESTMapper) String() string {
+	return fmt.Sprintf("FirstHitRESTMapper{\n\t%v\n}", m.MultiRESTMapper)
+}
+
+func (m FirstHitRESTMapper) ResourceFor(resource unversioned.GroupVersionResource) (unversioned.GroupVersionResource, error) {
+	errors := []error{}
+	for _, t := range m.MultiRESTMapper {
+		ret, err := t.ResourceFor(resource)
+		if err == nil {
+			return ret, nil
+		}
+		errors = append(errors, err)
+	}
+
+	return unversioned.GroupVersionResource{}, collapseAggregateErrors(errors)
+}
+
+func (m FirstHitRESTMapper) KindFor(resource unversioned.GroupVersionResource) (unversioned.GroupVersionKind, error) {
+	errors := []error{}
+	for _, t := range m.MultiRESTMapper {
+		ret, err := t.KindFor(resource)
+		if err == nil {
+			return ret, nil
+		}
+		errors = append(errors, err)
+	}
+
+	return unversioned.GroupVersionKind{}, collapseAggregateErrors(errors)
+}
+
+// RESTMapping provides the REST mapping for the resource based on the
+// kind and version. This implementation supports multiple REST schemas and
+// return the first match.
+func (m FirstHitRESTMapper) RESTMapping(gk unversioned.GroupKind, versions ...string) (*RESTMapping, error) {
+	errors := []error{}
+	for _, t := range m.MultiRESTMapper {
+		ret, err := t.RESTMapping(gk, versions...)
+		if err == nil {
+			return ret, nil
+		}
+		errors = append(errors, err)
+	}
+
+	return nil, collapseAggregateErrors(errors)
+}
+
+// collapseAggregateErrors returns the minimal errors.  it handles empty as nil, handles one item in a list
+// by returning the item, and collapses all NoMatchErrors to a single one (since they should all be the same)
+func collapseAggregateErrors(errors []error) error {
+	if len(errors) == 0 {
+		return nil
+	}
+	if len(errors) == 1 {
+		return errors[0]
+	}
+
+	allNoMatchErrors := true
+	for _, err := range errors {
+		allNoMatchErrors = allNoMatchErrors && IsNoMatchError(err)
+	}
+	if allNoMatchErrors {
+		return errors[0]
+	}
+
+	return utilerrors.NewAggregate(errors)
+}

pkg/client/typed/discovery/restmapper.go

@@ -17,6 +17,7 @@ limitations under the License.
 package discovery
 
 import (
+	"fmt"
 	"sync"
 
 	"k8s.io/kubernetes/pkg/api/errors"
@@ -259,5 +260,13 @@ func (d *DeferredDiscoveryRESTMapper) ResourceSingularizer(resource string) (sin
 	return del.ResourceSingularizer(resource)
 }
 
+func (d *DeferredDiscoveryRESTMapper) String() string {
+	del, err := d.getDelegate()
+	if err != nil {
+		return fmt.Sprintf("DeferredDiscoveryRESTMapper{%v}", err)
+	}
+	return fmt.Sprintf("DeferredDiscoveryRESTMapper{\n\t%v\n}", del)
+}
+
 // Make sure it satisfies the interface
 var _ meta.RESTMapper = &DeferredDiscoveryRESTMapper{}

pkg/kubectl/cmd/util/factory.go

@@ -315,9 +315,12 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 					// TODO eliminate this once we're truly generic.
 					thirdPartyResourceDataMapper := meta.NewDefaultRESTMapper([]unversioned.GroupVersion{extensionsv1beta1.SchemeGroupVersion}, registered.InterfacesFor)
 					thirdPartyResourceDataMapper.Add(extensionsv1beta1.SchemeGroupVersion.WithKind("ThirdPartyResourceData"), meta.RESTScopeNamespace)
-					mapper = meta.MultiRESTMapper{
-						discovery.NewDeferredDiscoveryRESTMapper(discoveryClient, registered.InterfacesFor),
-						thirdPartyResourceDataMapper,
+
+					mapper = meta.FirstHitRESTMapper{
+						MultiRESTMapper: meta.MultiRESTMapper{
+							discovery.NewDeferredDiscoveryRESTMapper(discoveryClient, registered.InterfacesFor),
+							thirdPartyResourceDataMapper,
+						},
 					}
 				}
 			}