Supplement unit tests to kubectl create rolebinding command.

Supplement unit tests to `kubectl create rolebinding` command,
including:
1. Unit tests for pkg/kubectl/role.go
2. Unit tests for pkg/kubectl/cmd/create_role.go

pkg/kubectl/cmd/create_rolebinding_test.go

@@ -0,0 +1,140 @@
+/*
+Copyright 2017 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 cmd
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"reflect"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	restclient "k8s.io/client-go/rest"
+	"k8s.io/client-go/rest/fake"
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/apis/rbac"
+	cmdtesting "k8s.io/kubernetes/pkg/kubectl/cmd/testing"
+)
+
+var groupVersion = schema.GroupVersion{Group: "rbac.authorization.k8s.io", Version: "v1alpha1"}
+
+func TestCreateRoleBinding(t *testing.T) {
+	expectBinding := &rbac.RoleBinding{
+		ObjectMeta: v1.ObjectMeta{
+			Name: "fake-binding",
+		},
+		RoleRef: rbac.RoleRef{
+			APIGroup: rbac.GroupName,
+			Kind:     "Role",
+			Name:     "fake-role",
+		},
+		Subjects: []rbac.Subject{
+			{
+				Kind:     rbac.UserKind,
+				APIGroup: "rbac.authorization.k8s.io",
+				Name:     "fake-user",
+			},
+			{
+				Kind:     rbac.GroupKind,
+				APIGroup: "rbac.authorization.k8s.io",
+				Name:     "fake-group",
+			},
+			{
+				Kind:      rbac.ServiceAccountKind,
+				Namespace: "fake-namespace",
+				Name:      "fake-account",
+			},
+		},
+	}
+
+	f, tf, _, ns := cmdtesting.NewAPIFactory()
+
+	info, _ := runtime.SerializerInfoForMediaType(ns.SupportedMediaTypes(), runtime.ContentTypeJSON)
+	encoder := ns.EncoderForVersion(info.Serializer, groupVersion)
+	decoder := ns.DecoderToVersion(info.Serializer, groupVersion)
+
+	tf.Namespace = "test"
+	tf.Printer = &testPrinter{}
+	tf.Client = &RoleBindingRESTClient{
+		RESTClient: &fake.RESTClient{
+			APIRegistry:          api.Registry,
+			NegotiatedSerializer: ns,
+			Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
+				switch p, m := req.URL.Path, req.Method; {
+				case p == "/namespaces/test/rolebindings" && m == "POST":
+					bodyBits, err := ioutil.ReadAll(req.Body)
+					if err != nil {
+						t.Fatalf("TestCreateRoleBinding error: %v", err)
+						return nil, nil
+					}
+
+					if obj, _, err := decoder.Decode(bodyBits, nil, &rbac.RoleBinding{}); err == nil {
+						if !reflect.DeepEqual(obj.(*rbac.RoleBinding), expectBinding) {
+							t.Fatalf("TestCreateRoleBinding: expected:\n%#v\nsaw:\n%#v", expectBinding, obj.(*rbac.RoleBinding))
+							return nil, nil
+						}
+					} else {
+						t.Fatalf("TestCreateRoleBinding error, could not decode the request body into rbac.RoleBinding object: %v", err)
+						return nil, nil
+					}
+
+					responseBinding := &rbac.RoleBinding{}
+					responseBinding.Name = "fake-binding"
+					return &http.Response{StatusCode: 201, Header: defaultHeader(), Body: ioutil.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(encoder, responseBinding))))}, nil
+				default:
+					t.Fatalf("unexpected request: %#v\n%#v", req.URL, req)
+					return nil, nil
+				}
+			}),
+		},
+	}
+
+	buf := bytes.NewBuffer([]byte{})
+	cmd := NewCmdCreateRoleBinding(f, buf)
+	cmd.Flags().Set("role", "fake-role")
+	cmd.Flags().Set("user", "fake-user")
+	cmd.Flags().Set("group", "fake-group")
+	cmd.Flags().Set("serviceaccount", "fake-namespace:fake-account")
+	cmd.Run(cmd, []string{"fake-binding"})
+}
+
+type RoleBindingRESTClient struct {
+	*fake.RESTClient
+}
+
+func (c *RoleBindingRESTClient) Post() *restclient.Request {
+	config := restclient.ContentConfig{
+		ContentType:          runtime.ContentTypeJSON,
+		GroupVersion:         &groupVersion,
+		NegotiatedSerializer: c.NegotiatedSerializer,
+	}
+
+	info, _ := runtime.SerializerInfoForMediaType(c.NegotiatedSerializer.SupportedMediaTypes(), runtime.ContentTypeJSON)
+	serializers := restclient.Serializers{
+		Encoder: c.NegotiatedSerializer.EncoderForVersion(info.Serializer, groupVersion),
+		Decoder: c.NegotiatedSerializer.DecoderToVersion(info.Serializer, groupVersion),
+	}
+	if info.StreamSerializer != nil {
+		serializers.StreamingSerializer = info.StreamSerializer.Serializer
+		serializers.Framer = info.StreamSerializer.Framer
+	}
+	return restclient.NewRequest(c, "POST", &url.URL{Host: "localhost"}, c.VersionedAPIPath, config, serializers, nil, nil)
+}