fix(serving): Remove hardcoded GVK and look it up from schema

Fixes knative#133.

pkg/kn/commands/revision/revision_describe.go

@@ -20,7 +20,6 @@ import (
 	"github.com/knative/client/pkg/kn/commands"
 	"github.com/spf13/cobra"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 )
 
@@ -52,10 +51,10 @@ func NewRevisionDescribeCommand(p *commands.KnParams) *cobra.Command {
 			if err != nil {
 				return err
 			}
-			revision.GetObjectKind().SetGroupVersionKind(schema.GroupVersionKind{
-				Group:   "knative.dev",
-				Version: "v1alpha1",
-				Kind:    "Revision"})
+			if err := client.UpdateGroupVersionKind(revision); err != nil {
+				return err
+			}
+
 			err = printer.PrintObj(revision, cmd.OutOrStdout())
 			if err != nil {
 				return err

pkg/kn/commands/revision/revision_get.go

@@ -20,7 +20,6 @@ import (
 	"github.com/knative/client/pkg/kn/commands"
 	"github.com/spf13/cobra"
 	"k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
 // NewRevisionGetCommand represents 'kn revision get' command
@@ -47,10 +46,10 @@ func NewRevisionGetCommand(p *commands.KnParams) *cobra.Command {
 				fmt.Fprintf(cmd.OutOrStdout(), "No resources found.\n")
 				return nil
 			}
-			revision.GetObjectKind().SetGroupVersionKind(schema.GroupVersionKind{
-				Group:   "knative.dev",
-				Version: "v1alpha1",
-				Kind:    "revision"})
+			if err := client.UpdateGroupVersionKind(revision); err != nil {
+				return err
+			}
+
 			printer, err := revisionGetFlags.ToPrinter()
 			if err != nil {
 				return err

pkg/kn/commands/service/service_describe.go

@@ -20,7 +20,6 @@ import (
 	"github.com/knative/client/pkg/kn/commands"
 	"github.com/spf13/cobra"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 )
 
@@ -51,10 +50,10 @@ func NewServiceDescribeCommand(p *commands.KnParams) *cobra.Command {
 			if err != nil {
 				return err
 			}
-			describeService.GetObjectKind().SetGroupVersionKind(schema.GroupVersionKind{
-				Group:   "knative.dev",
-				Version: "v1alpha1",
-				Kind:    "Service"})
+			if err := client.UpdateGroupVersionKind(describeService); err != nil {
+				return err
+			}
+
 			err = printer.PrintObj(describeService, cmd.OutOrStdout())
 			if err != nil {
 				return err

pkg/kn/commands/service/service_get.go

@@ -20,7 +20,6 @@ import (
 	"github.com/knative/client/pkg/kn/commands"
 	"github.com/spf13/cobra"
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
 // NewServiceGetCommand represents 'kn service get' command
@@ -47,10 +46,9 @@ func NewServiceGetCommand(p *commands.KnParams) *cobra.Command {
 				fmt.Fprintf(cmd.OutOrStdout(), "No resources found.\n")
 				return nil
 			}
-			service.GetObjectKind().SetGroupVersionKind(schema.GroupVersionKind{
-				Group:   "knative.dev",
-				Version: "v1alpha1",
-				Kind:    "Service"})
+			if err := client.UpdateGroupVersionKind(service); err != nil {
+				return err
+			}
 
 			printer, err := serviceGetFlags.ToPrinter()
 			if err != nil {

pkg/kn/commands/test_helper.go

@@ -17,20 +17,23 @@ package commands
 import (
 	"bytes"
 	"flag"
+	"k8s.io/apimachinery/pkg/runtime"
 
-	serving "github.com/knative/serving/pkg/client/clientset/versioned/typed/serving/v1alpha1"
 	"github.com/knative/serving/pkg/client/clientset/versioned/typed/serving/v1alpha1/fake"
 	"github.com/spf13/cobra"
 	client_testing "k8s.io/client-go/testing"
+
+	servinglib "github.com/knative/client/pkg/serving"
+	serving_v1alpha1_api "github.com/knative/serving/pkg/apis/serving/v1alpha1"
 )
 
-func CreateTestKnCommand(cmd *cobra.Command, knParams *KnParams) (*cobra.Command, *fake.FakeServingV1alpha1, *bytes.Buffer) {
+func CreateTestKnCommand(cmd *cobra.Command, knParams *KnParams) (*cobra.Command, *fakeServingV1alpha1Wrapper, *bytes.Buffer) {
 	buf := new(bytes.Buffer)
-	fakeServing := &fake.FakeServingV1alpha1{&client_testing.Fake{}}
+	fakeServing := fakeServingV1alpha1Wrapper{&fake.FakeServingV1alpha1{&client_testing.Fake{}}}
 	knParams.Output = buf
-	knParams.ServingFactory = func() (serving.ServingV1alpha1Interface, error) { return fakeServing, nil }
+	knParams.ServingFactory = func() (ServingV1alpha1InterfaceWithGvkUpdater, error) { return fakeServing, nil }
 	knCommand := newKnCommand(cmd, knParams)
-	return knCommand, fakeServing, buf
+	return knCommand, &fakeServing, buf
 }
 
 func newKnCommand(subCommand *cobra.Command, params *KnParams) *cobra.Command {
@@ -64,3 +67,12 @@ Eventing: Manage event subscriptions and channels. Connect up event sources.`,
 	flag.CommandLine.Parse([]string{})
 	return rootCmd
 }
+
+// Helper struct to adding UpdateGroupVersionKind to the fake client, too
+type fakeServingV1alpha1Wrapper struct {
+	*fake.FakeServingV1alpha1
+}
+
+func (fakeServingV1alpha1Wrapper) UpdateGroupVersionKind(obj runtime.Object) error {
+	return servinglib.UpdateGroupVersionKind(obj, serving_v1alpha1_api.SchemeGroupVersion)
+}

pkg/kn/commands/types.go

@@ -16,8 +16,12 @@ package commands
 
 import (
 	"io"
+	"k8s.io/apimachinery/pkg/runtime"
 
-	serving "github.com/knative/serving/pkg/client/clientset/versioned/typed/serving/v1alpha1"
+	servinglib "github.com/knative/client/pkg/serving"
+
+	serving_v1alpha1_api "github.com/knative/serving/pkg/apis/serving/v1alpha1"
+	serving_v1alpha1_client "github.com/knative/serving/pkg/client/clientset/versioned/typed/serving/v1alpha1"
 	"k8s.io/client-go/tools/clientcmd"
 )
 
@@ -27,10 +31,28 @@ var CfgFile string
 // KubeCfgFile is the path for the Kubernetes config
 var KubeCfgFile string
 
+// Extend v1alpha1 serving client by a method for updating GVK
+type ServingV1alpha1InterfaceWithGvkUpdater interface {
+	serving_v1alpha1_client.ServingV1alpha1Interface
+
+	// Update with the registered V1alpha1 GVK
+	UpdateGroupVersionKind(obj runtime.Object) error
+}
+
+// Delegate to v1alpha1 client
+type ServingV1alphaClientWithGvkUpdater struct {
+	*serving_v1alpha1_client.ServingV1alpha1Client
+}
+
+// Update GVK from v1alpha1 schema. Needs to be called by any object returned from the client
+func (cl ServingV1alphaClientWithGvkUpdater) UpdateGroupVersionKind(obj runtime.Object) error {
+	return servinglib.UpdateGroupVersionKind(obj, serving_v1alpha1_api.SchemeGroupVersion)
+}
+
 // Parameters for creating commands. Useful for inserting mocks for testing.
 type KnParams struct {
 	Output         io.Writer
-	ServingFactory func() (serving.ServingV1alpha1Interface, error)
+	ServingFactory func() (ServingV1alpha1InterfaceWithGvkUpdater, error)
 }
 
 func (c *KnParams) Initialize() {
@@ -39,14 +61,14 @@ func (c *KnParams) Initialize() {
 	}
 }
 
-func GetConfig() (serving.ServingV1alpha1Interface, error) {
+func GetConfig() (ServingV1alpha1InterfaceWithGvkUpdater, error) {
 	config, err := clientcmd.BuildConfigFromFlags("", KubeCfgFile)
 	if err != nil {
 		return nil, err
 	}
-	client, err := serving.NewForConfig(config)
+	client, err := serving_v1alpha1_client.NewForConfig(config)
 	if err != nil {
 		return nil, err
 	}
-	return client, nil
+	return ServingV1alphaClientWithGvkUpdater{client}, nil
 }

pkg/serving/schema_handling.go

@@ -0,0 +1,34 @@
+package serving
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/knative/serving/pkg/client/clientset/versioned/scheme"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// Update the GVK on the given object, based on the GVK registered in into the serving scheme
+// for the given GroupVersion
+func UpdateGroupVersionKind(obj runtime.Object, gv schema.GroupVersion) error {
+	gvk, err := getGroupVersionKind(obj, gv)
+	if err != nil {
+		return err
+	}
+	obj.GetObjectKind().SetGroupVersionKind(*gvk)
+	return nil
+}
+
+func getGroupVersionKind(obj runtime.Object, gv schema.GroupVersion) (*schema.GroupVersionKind, error) {
+	gvks, _, err := scheme.Scheme.ObjectKinds(obj)
+	if err != nil {
+		return nil, err
+	}
+	for _, gvk := range gvks {
+		if gvk.GroupVersion() == gv {
+			return &gvk, nil
+		}
+	}
+	return nil, errors.New(fmt.Sprintf("no group version %s registered in %s", gv, scheme.Scheme.Name()))
+}

pkg/serving/schema_handling_test.go

@@ -0,0 +1,29 @@
+package serving
+
+import (
+	"github.com/knative/serving/pkg/apis/serving/v1alpha1"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"testing"
+)
+
+func TestGVKUpdate(t *testing.T) {
+	service := v1alpha1.Service{}
+	err := UpdateGroupVersionKind(&service, v1alpha1.SchemeGroupVersion)
+	if err != nil {
+		t.Fatalf("cannot update GVK to a service %v", err)
+	}
+	if service.Kind != "Service" {
+		t.Fatalf("wrong kind '%s'", service.Kind)
+	}
+	if service.APIVersion != v1alpha1.SchemeGroupVersion.Group+"/"+v1alpha1.SchemeGroupVersion.Version {
+		t.Fatalf("wrong version '%s'", service.APIVersion)
+	}
+}
+
+func TestGVKUpdateNegative(t *testing.T) {
+	service := v1alpha1.Service{}
+	err := UpdateGroupVersionKind(&service, schema.GroupVersion{Group: "bla", Version: "blub"})
+	if err == nil {
+		t.Fatal("expect an error for an unregistered group version")
+	}
+}