update more kubectl bits for groupversion

pkg/api/latest/latest.go

@@ -42,6 +42,12 @@ var (
 	IsRegistered = allGroups.IsRegistered
 )
 
+// ExternalVersions is a list of all external versions for this API group in order of
+// most preferred to least preferred
+var ExternalVersions = []unversioned.GroupVersion{
+	{Group: "", Version: "v1"},
+}
+
 // GroupMetaMap is a map between group names and their metadata.
 type GroupMetaMap map[string]*GroupMeta
 

pkg/client/unversioned/client.go

@@ -27,6 +27,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/unversioned"
+	"k8s.io/kubernetes/pkg/api/v1"
 	"k8s.io/kubernetes/pkg/version"
 )
 
@@ -183,12 +184,12 @@ func (c *Client) ValidateComponents() (*api.ComponentStatusList, error) {
 // SwaggerSchemaInterface has a method to retrieve the swagger schema. Used in
 // client.Interface
 type SwaggerSchemaInterface interface {
-	SwaggerSchema(groupVersion string) (*swagger.ApiDeclaration, error)
+	SwaggerSchema(version unversioned.GroupVersion) (*swagger.ApiDeclaration, error)
 }
 
 // SwaggerSchema retrieves and parses the swagger API schema the server supports.
-func (c *Client) SwaggerSchema(groupVersion string) (*swagger.ApiDeclaration, error) {
+func (c *Client) SwaggerSchema(version unversioned.GroupVersion) (*swagger.ApiDeclaration, error) {
-	if groupVersion == "" {
+	if version.IsEmpty() {
 		return nil, fmt.Errorf("groupVersion cannot be empty")
 	}
 
@@ -198,14 +199,14 @@ func (c *Client) SwaggerSchema(groupVersion string) (*swagger.ApiDeclaration, er
 	}
 	groupVersions := ExtractGroupVersions(groupList)
 	// This check also takes care the case that kubectl is newer than the running endpoint
-	if stringDoesntExistIn(groupVersion, groupVersions) {
+	if stringDoesntExistIn(version.String(), groupVersions) {
-		return nil, fmt.Errorf("API version: %s is not supported by the server. Use one of: %v", groupVersion, groupVersions)
+		return nil, fmt.Errorf("API version: %v is not supported by the server. Use one of: %v", version, groupVersions)
 	}
 	var path string
-	if groupVersion == "v1" {
+	if version == v1.SchemeGroupVersion {
-		path = "/swaggerapi/api/" + groupVersion
+		path = "/swaggerapi/api/" + version.Version
 	} else {
-		path = "/swaggerapi/apis/" + groupVersion
+		path = "/swaggerapi/apis/" + version.Group + "/" + version.Version
 	}
 
 	body, err := c.Get().AbsPath(path).Do().Raw()

pkg/client/unversioned/client_test.go

@@ -31,6 +31,7 @@ import (
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/testapi"
 	"k8s.io/kubernetes/pkg/api/unversioned"
+	"k8s.io/kubernetes/pkg/api/v1"
 	"k8s.io/kubernetes/pkg/fields"
 	"k8s.io/kubernetes/pkg/labels"
 	"k8s.io/kubernetes/pkg/runtime"
@@ -496,7 +497,7 @@ func TestGetSwaggerSchema(t *testing.T) {
 	}
 
 	client := NewOrDie(&Config{Host: server.URL})
-	got, err := client.SwaggerSchema("v1")
+	got, err := client.SwaggerSchema(v1.SchemeGroupVersion)
 	if err != nil {
 		t.Fatalf("unexpected encoding error: %v", err)
 	}
@@ -506,7 +507,7 @@ func TestGetSwaggerSchema(t *testing.T) {
 }
 
 func TestGetSwaggerSchemaFail(t *testing.T) {
-	expErr := "API version: v4 is not supported by the server. Use one of: [v1 v2 v3]"
+	expErr := "API version: api.group/v4 is not supported by the server. Use one of: [v1 v2 v3]"
 
 	server, err := swaggerSchemaFakeServer()
 	if err != nil {
@@ -514,7 +515,7 @@ func TestGetSwaggerSchemaFail(t *testing.T) {
 	}
 
 	client := NewOrDie(&Config{Host: server.URL})
-	got, err := client.SwaggerSchema("v4")
+	got, err := client.SwaggerSchema(unversioned.GroupVersion{Group: "api.group", Version: "v4"})
 	if got != nil {
 		t.Fatalf("unexpected response: %v", got)
 	}

pkg/client/unversioned/clientcmd/api/latest/latest.go

@@ -17,6 +17,7 @@ limitations under the License.
 package latest
 
 import (
+	"k8s.io/kubernetes/pkg/api/unversioned"
 	"k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api/v1"
 	"k8s.io/kubernetes/pkg/runtime"
 )
@@ -24,6 +25,8 @@ import (
 // Version is the string that represents the current external default version.
 const Version = "v1"
 
+var ExternalVersion = unversioned.GroupVersion{Group: "", Version: "v1"}
+
 // OldestVersion is the string that represents the oldest server version supported,
 // for client code that wants to hardcode the lowest common denominator.
 const OldestVersion = "v1"

pkg/client/unversioned/testclient/testclient.go

@@ -25,6 +25,7 @@ import (
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/registered"
 	"k8s.io/kubernetes/pkg/api/unversioned"
+	"k8s.io/kubernetes/pkg/api/v1"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/version"
@@ -306,10 +307,14 @@ func (c *Fake) ComponentStatuses() client.ComponentStatusInterface {
 }
 
 // SwaggerSchema returns an empty swagger.ApiDeclaration for testing
-func (c *Fake) SwaggerSchema(version string) (*swagger.ApiDeclaration, error) {
+func (c *Fake) SwaggerSchema(version unversioned.GroupVersion) (*swagger.ApiDeclaration, error) {
 	action := ActionImpl{}
 	action.Verb = "get"
-	action.Resource = "/swaggerapi/api/" + version
+	if version == v1.SchemeGroupVersion {
+		action.Resource = "/swaggerapi/api/" + version.Version
+	} else {
+		action.Resource = "/swaggerapi/apis/" + version.Group + "/" + version.Version
+	}
 
 	c.Invokes(action, nil)
 	return &swagger.ApiDeclaration{}, nil

pkg/kubectl/cmd/autoscale.go

@@ -95,7 +95,7 @@ func RunAutoscale(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []
 	}
 	info := infos[0]
 	mapping := info.ResourceMapping()
-	if err := f.CanBeAutoscaled(mapping.GroupVersionKind.Kind); err != nil {
+	if err := f.CanBeAutoscaled(mapping.GroupVersionKind.GroupKind()); err != nil {
 		return err
 	}
 

pkg/kubectl/cmd/config/view.go

@@ -21,7 +21,6 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/golang/glog"
 	"github.com/spf13/cobra"
 
 	"k8s.io/kubernetes/pkg/client/unversioned/clientcmd"
@@ -70,16 +69,12 @@ func NewCmdConfigView(out io.Writer, ConfigAccess ConfigAccess) *cobra.Command {
 			}
 
 			printer, _, err := cmdutil.PrinterForCommand(cmd)
-			if err != nil {
+			cmdutil.CheckErr(err)
-				glog.FatalDepth(1, err)
+			version, err := cmdutil.OutputVersion(cmd, &latest.ExternalVersion)
-			}
+			cmdutil.CheckErr(err)
-			version := cmdutil.OutputVersion(cmd, latest.Version)
 			printer = kubectl.NewVersionedPrinter(printer, clientcmdapi.Scheme, version)
 
-			if err := options.Run(out, printer); err != nil {
+			cmdutil.CheckErr(options.Run(out, printer))
-				glog.FatalDepth(1, err)
-			}
-
 		},
 	}
 

pkg/kubectl/cmd/convert.go

@@ -90,17 +90,16 @@ type ConvertOptions struct {
 	out     io.Writer
 	printer kubectl.ResourcePrinter
 
-	outputVersion string
+	outputVersion unversioned.GroupVersion
 }
 
 // Complete collects information required to run Convert command from command line.
 func (o *ConvertOptions) Complete(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string) (err error) {
-	o.outputVersion = cmdutil.OutputVersion(cmd, latest.GroupOrDie("").GroupVersion.Version)
+	o.outputVersion, err = cmdutil.OutputVersion(cmd, &latest.ExternalVersions[0])
-	outputGV, err := unversioned.ParseGroupVersion(o.outputVersion)
 	if err != nil {
-		return fmt.Errorf("unable to parse group/version from %q: %v", o.outputVersion, err)
+		return err
 	}
-	if !registered.IsRegisteredAPIGroupVersion(outputGV) {
+	if !registered.IsRegisteredAPIGroupVersion(o.outputVersion) {
 		cmdutil.UsageError(cmd, "'%s' is not a registered version.", o.outputVersion)
 	}
 
@@ -152,7 +151,7 @@ func (o *ConvertOptions) RunConvert() error {
 		return err
 	}
 
-	objects, err := resource.AsVersionedObject(infos, false, o.outputVersion)
+	objects, err := resource.AsVersionedObject(infos, false, o.outputVersion.String())
 	if err != nil {
 		return err
 	}

pkg/kubectl/cmd/edit.go

@@ -28,6 +28,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/errors"
+	"k8s.io/kubernetes/pkg/api/unversioned"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/kubectl"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
@@ -149,10 +150,13 @@ func RunEdit(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []strin
 
 	windowsLineEndings := cmdutil.GetFlagBool(cmd, "windows-line-endings")
 	edit := editor.NewDefaultEditor(f.EditorEnvs())
-	defaultVersion := cmdutil.OutputVersionFromGroupVersion(cmd, clientConfig.GroupVersion)
+	defaultVersion, err := cmdutil.OutputVersion(cmd, clientConfig.GroupVersion)
+	if err != nil {
+		return err
+	}
 	results := editResults{}
 	for {
-		objs, err := resource.AsVersionedObjects(infos, defaultVersion)
+		objs, err := resource.AsVersionedObjects(infos, defaultVersion.String())
 		if err != nil {
 			return preservedFile(err, results.file, out)
 		}
@@ -356,7 +360,7 @@ type editResults struct {
 	edit      []*resource.Info
 	file      string
 
-	version string
+	version unversioned.GroupVersion
 }
 
 func (r *editResults) addError(err error, info *resource.Info) string {

pkg/kubectl/cmd/explain.go

@@ -22,6 +22,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"k8s.io/kubernetes/pkg/api/latest"
+	"k8s.io/kubernetes/pkg/api/unversioned"
 	"k8s.io/kubernetes/pkg/kubectl"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
 )
@@ -70,7 +71,8 @@ func RunExplain(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []st
 	}
 
 	recursive := cmdutil.GetFlagBool(cmd, "recursive")
-	apiV := cmdutil.GetFlagString(cmd, "api-version")
+	apiVersionString := cmdutil.GetFlagString(cmd, "api-version")
+	apiVersion := unversioned.GroupVersion{}
 
 	mapper, _ := f.Object()
 	// TODO: After we figured out the new syntax to separate group and resource, allow
@@ -87,14 +89,21 @@ func RunExplain(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []st
 		return err
 	}
 
-	if len(apiV) == 0 {
+	if len(apiVersionString) == 0 {
 		groupMeta, err := latest.Group(gvk.Group)
 		if err != nil {
 			return err
 		}
-		apiV = groupMeta.GroupVersion.String()
+		apiVersion = groupMeta.GroupVersion
+
+	} else {
+		apiVersion, err = unversioned.ParseGroupVersion(apiVersionString)
+		if err != nil {
+			return nil
+		}
 	}
-	swagSchema, err := kubectl.GetSwaggerSchema(apiV, client)
+
+	swagSchema, err := kubectl.GetSwaggerSchema(apiVersion, client)
 	if err != nil {
 		return err
 	}

pkg/kubectl/cmd/expose.go

@@ -120,7 +120,7 @@ func RunExpose(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []str
 	}
 	info := infos[0]
 	mapping := info.ResourceMapping()
-	if err := f.CanBeExposed(mapping.GroupVersionKind.Kind); err != nil {
+	if err := f.CanBeExposed(mapping.GroupVersionKind.GroupKind()); err != nil {
 		return err
 	}
 	// Get the input object

pkg/kubectl/cmd/get.go

@@ -209,8 +209,11 @@ func RunGet(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string
 
 		// the outermost object will be converted to the output-version, but inner
 		// objects can use their mappings
-		version := cmdutil.OutputVersionFromGroupVersion(cmd, clientConfig.GroupVersion)
+		version, err := cmdutil.OutputVersion(cmd, clientConfig.GroupVersion)
-		obj, err := resource.AsVersionedObject(infos, !singular, version)
+		if err != nil {
+			return err
+		}
+		obj, err := resource.AsVersionedObject(infos, !singular, version.String())
 		if err != nil {
 			return err
 		}

pkg/kubectl/cmd/get_test.go

@@ -164,7 +164,7 @@ func TestGetUnknownSchemaObjectListGeneric(t *testing.T) {
 			rcVersion:       testapi.Default.Version(),
 		},
 		"handles second specific version": {
-			outputVersion:   "unlikelyversion",
+			outputVersion:   "unlikely.group/unlikelyversion",
 			listVersion:     testapi.Default.Version(),
 			testtypeVersion: unlikelyGV.String(),
 			rcVersion:       testapi.Default.Version(), // see expected behavior 3b

pkg/kubectl/cmd/util/factory.go

@@ -95,9 +95,9 @@ type Factory struct {
 	// Returns the generator for the provided generator name
 	Generator func(name string) (kubectl.Generator, bool)
 	// Check whether the kind of resources could be exposed
-	CanBeExposed func(kind string) error
+	CanBeExposed func(kind unversioned.GroupKind) error
 	// Check whether the kind of resources could be autoscaled
-	CanBeAutoscaled func(kind string) error
+	CanBeAutoscaled func(kind unversioned.GroupKind) error
 	// AttachablePodForObject returns the pod to which to attach given an object.
 	AttachablePodForObject func(object runtime.Object) (*api.Pod, error)
 	// EditorEnvs returns a group of environment variables that the edit command
@@ -140,12 +140,12 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 		Object: func() (meta.RESTMapper, runtime.ObjectTyper) {
 			cfg, err := clientConfig.ClientConfig()
 			CheckErr(err)
-			cmdApiVersion := ""
+			cmdApiVersion := unversioned.GroupVersion{}
 			if cfg.GroupVersion != nil {
-				cmdApiVersion = cfg.GroupVersion.String()
+				cmdApiVersion = *cfg.GroupVersion
 			}
 
-			return kubectl.OutputVersionMapper{RESTMapper: mapper, OutputVersion: cmdApiVersion}, api.Scheme
+			return kubectl.OutputVersionMapper{RESTMapper: mapper, OutputVersions: []unversioned.GroupVersion{cmdApiVersion}}, api.Scheme
 		},
 		Client: func() (*client.Client, error) {
 			return clients.ClientForVersion("")
@@ -163,9 +163,9 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 				return nil, err
 			}
 			switch gvk.Group {
-			case "":
+			case api.SchemeGroupVersion.Group:
 				return client.RESTClient, nil
-			case "extensions":
+			case extensions.SchemeGroupVersion.Group:
 				return client.ExtensionsClient.RESTClient, nil
 			}
 			return nil, fmt.Errorf("unable to get RESTClient for resource '%s'", mapping.Resource)
@@ -290,21 +290,21 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 			generator, ok := generators[name]
 			return generator, ok
 		},
-		CanBeExposed: func(kind string) error {
+		CanBeExposed: func(kind unversioned.GroupKind) error {
 			switch kind {
-			case "ReplicationController", "Service", "Pod":
+			case api.Kind("ReplicationController"), api.Kind("Service"), api.Kind("Pod"):
 				// nothing to do here
 			default:
 				return fmt.Errorf("cannot expose a %s", kind)
 			}
 			return nil
 		},
-		CanBeAutoscaled: func(kind string) error {
+		CanBeAutoscaled: func(kind unversioned.GroupKind) error {
 			switch kind {
-			case "ReplicationController", "Deployment":
+			case api.Kind("ReplicationController"), extensions.Kind("Deployment"):
 				// nothing to do here
 			default:
-				return fmt.Errorf("cannot autoscale a %s", kind)
+				return fmt.Errorf("cannot autoscale a %v", kind)
 			}
 			return nil
 		},
@@ -604,19 +604,20 @@ func (f *Factory) PrinterForMapping(cmd *cobra.Command, mapping *meta.RESTMappin
 		if err != nil {
 			return nil, err
 		}
-		defaultVersion := ""
-		if clientConfig.GroupVersion != nil {
-			defaultVersion = clientConfig.GroupVersion.String()
-		}
 
-		version := OutputVersion(cmd, defaultVersion)
+		version, err := OutputVersion(cmd, clientConfig.GroupVersion)
-		if len(version) == 0 {
+		if err != nil {
-			version = mapping.GroupVersionKind.GroupVersion().String()
+			return nil, err
 		}
-		if len(version) == 0 {
+		if version.IsEmpty() {
+			version = mapping.GroupVersionKind.GroupVersion()
+		}
+		if version.IsEmpty() {
 			return nil, fmt.Errorf("you must specify an output-version when using this output format")
 		}
-		printer = kubectl.NewVersionedPrinter(printer, mapping.ObjectConvertor, version, mapping.GroupVersionKind.GroupVersion().String())
+
+		printer = kubectl.NewVersionedPrinter(printer, mapping.ObjectConvertor, version, mapping.GroupVersionKind.GroupVersion())
+
 	} else {
 		// Some callers do not have "label-columns" so we can't use the GetFlagStringSlice() helper
 		columnLabel, err := cmd.Flags().GetStringSlice("label-columns")
@@ -629,6 +630,7 @@ func (f *Factory) PrinterForMapping(cmd *cobra.Command, mapping *meta.RESTMappin
 		}
 		printer = maybeWrapSortingPrinter(cmd, printer)
 	}
+
 	return printer, nil
 }
 

pkg/kubectl/cmd/util/factory_test.go

@@ -170,15 +170,15 @@ func TestLabelsForObject(t *testing.T) {
 func TestCanBeExposed(t *testing.T) {
 	factory := NewFactory(nil)
 	tests := []struct {
-		kind      string
+		kind      unversioned.GroupKind
 		expectErr bool
 	}{
 		{
-			kind:      "ReplicationController",
+			kind:      api.Kind("ReplicationController"),
 			expectErr: false,
 		},
 		{
-			kind:      "Node",
+			kind:      api.Kind("Node"),
 			expectErr: true,
 		},
 	}

pkg/kubectl/cmd/util/printing.go

@@ -76,22 +76,18 @@ func ValidateOutputArgs(cmd *cobra.Command) error {
 }
 
 // OutputVersion returns the preferred output version for generic content (JSON, YAML, or templates)
-// TODO, when this has no callers, replace it with OutputVersionFromGroupVersion.  Also this shoudl return a GroupVersion
+// defaultVersion is never mutated.  Nil simply allows clean passing in common usage from client.Config
-func OutputVersion(cmd *cobra.Command, defaultVersion string) string {
+func OutputVersion(cmd *cobra.Command, defaultVersion *unversioned.GroupVersion) (unversioned.GroupVersion, error) {
-	outputVersion := GetFlagString(cmd, "output-version")
+	outputVersionString := GetFlagString(cmd, "output-version")
-	if len(outputVersion) == 0 {
+	if len(outputVersionString) == 0 {
-		outputVersion = defaultVersion
+		if defaultVersion == nil {
-	}
+			return unversioned.GroupVersion{}, nil
-	return outputVersion
+		}
-}
 
-// OutputVersionFromGroupVersion returns the preferred output version for generic content (JSON, YAML, or templates)
+		return *defaultVersion, nil
-func OutputVersionFromGroupVersion(cmd *cobra.Command, defaultGV *unversioned.GroupVersion) string {
-	outputVersion := GetFlagString(cmd, "output-version")
-	if len(outputVersion) == 0 && defaultGV != nil {
-		outputVersion = defaultGV.String()
 	}
-	return outputVersion
+
+	return unversioned.ParseGroupVersion(outputVersionString)
 }
 
 // PrinterForCommand returns the default printer for this command.

pkg/kubectl/explain.go

@@ -24,6 +24,7 @@ import (
 	"github.com/emicklei/go-restful/swagger"
 
 	"k8s.io/kubernetes/pkg/api/meta"
+	"k8s.io/kubernetes/pkg/api/unversioned"
 	apiutil "k8s.io/kubernetes/pkg/api/util"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 )
@@ -32,8 +33,8 @@ var allModels = make(map[string]*swagger.NamedModel)
 var recursive = false // this is global for convenience, can become int for multiple levels
 
 // GetSwaggerSchema returns the swagger spec from master
-func GetSwaggerSchema(apiVer string, kubeClient client.Interface) (*swagger.ApiDeclaration, error) {
+func GetSwaggerSchema(version unversioned.GroupVersion, kubeClient client.Interface) (*swagger.ApiDeclaration, error) {
-	swaggerSchema, err := kubeClient.SwaggerSchema(apiVer)
+	swaggerSchema, err := kubeClient.SwaggerSchema(version)
 	if err != nil {
 		return nil, fmt.Errorf("couldn't read swagger schema from server: %v", err)
 	}

pkg/kubectl/kubectl.go

@@ -47,14 +47,24 @@ func makeImageList(spec *api.PodSpec) string {
 // correspond to a preferred output version (if feasible)
 type OutputVersionMapper struct {
 	meta.RESTMapper
-	OutputVersion string
+
+	// output versions takes a list of preferred GroupVersions. Only the first
+	// hit for a given group will have effect.  This allows different output versions
+	// depending upon the group of the kind being requested
+	OutputVersions []unversioned.GroupVersion
 }
 
 // RESTMapping implements meta.RESTMapper by prepending the output version to the preferred version list.
 func (m OutputVersionMapper) RESTMapping(gk unversioned.GroupKind, versions ...string) (*meta.RESTMapping, error) {
-	mapping, err := m.RESTMapper.RESTMapping(gk, m.OutputVersion)
+	for _, preferredVersion := range m.OutputVersions {
-	if err == nil {
+		if gk.Group == preferredVersion.Group {
-		return mapping, nil
+			mapping, err := m.RESTMapper.RESTMapping(gk, preferredVersion.Version)
+			if err == nil {
+				return mapping, nil
+			}
+
+			break
+		}
 	}
 
 	return m.RESTMapper.RESTMapping(gk, versions...)

pkg/kubectl/resource_printer.go

@@ -157,28 +157,28 @@ func (fn ResourcePrinterFunc) HandledResources() []string {
 type VersionedPrinter struct {
 	printer   ResourcePrinter
 	convertor runtime.ObjectConvertor
-	version   []string
+	versions  []unversioned.GroupVersion
 }
 
 // NewVersionedPrinter wraps a printer to convert objects to a known API version prior to printing.
-func NewVersionedPrinter(printer ResourcePrinter, convertor runtime.ObjectConvertor, version ...string) ResourcePrinter {
+func NewVersionedPrinter(printer ResourcePrinter, convertor runtime.ObjectConvertor, versions ...unversioned.GroupVersion) ResourcePrinter {
 	return &VersionedPrinter{
 		printer:   printer,
 		convertor: convertor,
-		version:   version,
+		versions:  versions,
 	}
 }
 
 // PrintObj implements ResourcePrinter
 func (p *VersionedPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
-	if len(p.version) == 0 {
+	if len(p.versions) == 0 {
 		return fmt.Errorf("no version specified, object cannot be converted")
 	}
-	for _, version := range p.version {
+	for _, version := range p.versions {
-		if len(version) == 0 {
+		if version.IsEmpty() {
 			continue
 		}
-		converted, err := p.convertor.ConvertToVersion(obj, version)
+		converted, err := p.convertor.ConvertToVersion(obj, version.String())
 		if conversion.IsNotRegisteredError(err) {
 			continue
 		}
@@ -187,7 +187,7 @@ func (p *VersionedPrinter) PrintObj(obj runtime.Object, w io.Writer) error {
 		}
 		return p.printer.PrintObj(converted, w)
 	}
-	return fmt.Errorf("the object cannot be converted to any of the versions: %v", p.version)
+	return fmt.Errorf("the object cannot be converted to any of the versions: %v", p.versions)
 }
 
 // TODO: implement HandledResources()

pkg/kubectl/resource_printer_test.go

@@ -64,7 +64,7 @@ func TestVersionedPrinter(t *testing.T) {
 			return nil
 		}),
 		api.Scheme,
-		testapi.Default.Version(),
+		*testapi.Default.GroupVersion(),
 	)
 	if err := p.PrintObj(original, nil); err != nil {
 		t.Errorf("unexpected error: %v", err)
@@ -422,7 +422,7 @@ func TestTemplateStrings(t *testing.T) {
 		t.Fatalf("tmpl fail: %v", err)
 	}
 
-	printer := NewVersionedPrinter(p, api.Scheme, testapi.Default.Version())
+	printer := NewVersionedPrinter(p, api.Scheme, *testapi.Default.GroupVersion())
 
 	for name, item := range table {
 		buffer := &bytes.Buffer{}