Merge pull request #103516 from ykakarap/kubectl-subresources-apiserver

kubectl: apiserver changes to add --subresource support

pkg/printers/internalversion/printers.go

@@ -27,6 +27,7 @@ import (
 
 	apiserverinternalv1alpha1 "k8s.io/api/apiserverinternal/v1alpha1"
 	appsv1beta1 "k8s.io/api/apps/v1beta1"
+	autoscalingv1 "k8s.io/api/autoscaling/v1"
 	autoscalingv2beta1 "k8s.io/api/autoscaling/v2beta1"
 	batchv1 "k8s.io/api/batch/v1"
 	batchv1beta1 "k8s.io/api/batch/v1beta1"
@@ -582,6 +583,13 @@ func AddHandlers(h printers.PrintHandler) {
 	}
 	h.TableHandler(storageVersionColumnDefinitions, printStorageVersion)
 	h.TableHandler(storageVersionColumnDefinitions, printStorageVersionList)
+
+	scaleColumnDefinitions := []metav1.TableColumnDefinition{
+		{Name: "Name", Type: "string", Description: metav1.ObjectMeta{}.SwaggerDoc()["name"]},
+		{Name: "Desired", Type: "integer", Description: autoscalingv1.ScaleSpec{}.SwaggerDoc()["replicas"]},
+		{Name: "Available", Type: "integer", Description: autoscalingv1.ScaleStatus{}.SwaggerDoc()["replicas"]},
+	}
+	h.TableHandler(scaleColumnDefinitions, printScale)
 }
 
 // Pass ports=nil for all ports.
@@ -2615,6 +2623,14 @@ func printPriorityLevelConfigurationList(list *flowcontrol.PriorityLevelConfigur
 	return rows, nil
 }
 
+func printScale(obj *autoscaling.Scale, options printers.GenerateOptions) ([]metav1.TableRow, error) {
+	row := metav1.TableRow{
+		Object: runtime.RawExtension{Object: obj},
+	}
+	row.Cells = append(row.Cells, obj.Name, obj.Spec.Replicas, obj.Status.Replicas)
+	return []metav1.TableRow{row}, nil
+}
+
 func printBoolPtr(value *bool) string {
 	if value != nil {
 		return printBool(*value)

pkg/printers/internalversion/printers_test.go

@@ -5823,3 +5823,40 @@ func TestPrintStorageVersion(t *testing.T) {
 		}
 	}
 }
+
+func TestPrintScale(t *testing.T) {
+	tests := []struct {
+		scale    autoscaling.Scale
+		options  printers.GenerateOptions
+		expected []metav1.TableRow
+	}{
+		{
+			scale: autoscaling.Scale{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:              "test-autoscaling",
+					CreationTimestamp: metav1.Time{Time: time.Now().Add(1.9e9)},
+				},
+				Spec:   autoscaling.ScaleSpec{Replicas: 2},
+				Status: autoscaling.ScaleStatus{Replicas: 1},
+			},
+			expected: []metav1.TableRow{
+				{
+					Cells: []interface{}{"test-autoscaling", int32(2), int32(1)},
+				},
+			},
+		},
+	}
+
+	for i, test := range tests {
+		rows, err := printScale(&test.scale, test.options)
+		if err != nil {
+			t.Fatal(err)
+		}
+		for i := range rows {
+			rows[i].Object.Object = nil
+		}
+		if !reflect.DeepEqual(test.expected, rows) {
+			t.Errorf("%d mismatch: %s", i, diff.ObjectReflectDiff(test.expected, rows))
+		}
+	}
+}

pkg/registry/apiserverinternal/storageversion/storage/storage.go

@@ -89,3 +89,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/apps/daemonset/storage/storage.go

@@ -104,3 +104,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/apps/deployment/storage/storage.go

@@ -157,6 +157,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // RollbackREST implements the REST endpoint for initiating the rollback of a deployment
 type RollbackREST struct {
 	store *genericregistry.Store
@@ -315,6 +319,10 @@ func (r *ScaleREST) Update(ctx context.Context, name string, objInfo rest.Update
 	return newScale, false, nil
 }
 
+func (r *ScaleREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 func toScaleCreateValidation(f rest.ValidateObjectFunc) rest.ValidateObjectFunc {
 	return func(ctx context.Context, obj runtime.Object) error {
 		scale, err := scaleFromDeployment(obj.(*apps.Deployment))

pkg/registry/apps/replicaset/storage/storage.go

@@ -153,6 +153,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // ScaleREST implements a Scale for ReplicaSet.
 type ScaleREST struct {
 	store *genericregistry.Store
@@ -217,6 +221,10 @@ func (r *ScaleREST) Update(ctx context.Context, name string, objInfo rest.Update
 	return newScale, false, err
 }
 
+func (r *ScaleREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 func toScaleCreateValidation(f rest.ValidateObjectFunc) rest.ValidateObjectFunc {
 	return func(ctx context.Context, obj runtime.Object) error {
 		scale, err := scaleFromReplicaSet(obj.(*apps.ReplicaSet))

pkg/registry/apps/statefulset/storage/storage.go

@@ -141,6 +141,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // Implement ShortNamesProvider
 var _ rest.ShortNamesProvider = &REST{}
 
@@ -211,6 +215,10 @@ func (r *ScaleREST) Update(ctx context.Context, name string, objInfo rest.Update
 	return newScale, false, err
 }
 
+func (r *ScaleREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 func toScaleCreateValidation(f rest.ValidateObjectFunc) rest.ValidateObjectFunc {
 	return func(ctx context.Context, obj runtime.Object) error {
 		scale, err := scaleFromStatefulSet(obj.(*apps.StatefulSet))

pkg/registry/autoscaling/horizontalpodautoscaler/storage/storage.go

@@ -104,3 +104,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/batch/cronjob/storage/storage.go

@@ -102,3 +102,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/batch/job/storage/storage.go

@@ -145,3 +145,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/certificates/certificates/storage/storage.go

@@ -106,6 +106,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 var _ = rest.Patcher(&StatusREST{})
 
 // ApprovalREST implements the REST endpoint for changing the approval state of a CSR.

pkg/registry/core/namespace/storage/storage.go

@@ -316,6 +316,11 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 func (r *FinalizeREST) New() runtime.Object {
 	return r.store.New()
 }

pkg/registry/core/node/storage/storage.go

@@ -83,6 +83,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // NewStorage returns a NodeStorage object that will work against nodes.
 func NewStorage(optsGetter generic.RESTOptionsGetter, kubeletClientConfig client.KubeletClientConfig, proxyTransport http.RoundTripper) (*NodeStorage, error) {
 	store := &genericregistry.Store{

pkg/registry/core/persistentvolume/storage/storage.go

@@ -99,3 +99,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/core/persistentvolumeclaim/storage/storage.go

@@ -143,3 +143,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/core/pod/storage/storage.go

@@ -299,6 +299,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // EphemeralContainersREST implements the REST endpoint for adding EphemeralContainers
 type EphemeralContainersREST struct {
 	store *genericregistry.Store

pkg/registry/core/replicationcontroller/storage/storage.go

@@ -148,6 +148,10 @@ func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 type ScaleREST struct {
 	store *genericregistry.Store
 }
@@ -196,6 +200,10 @@ func (r *ScaleREST) Update(ctx context.Context, name string, objInfo rest.Update
 	return scaleFromRC(rc), false, nil
 }
 
+func (r *ScaleREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 func toScaleCreateValidation(f rest.ValidateObjectFunc) rest.ValidateObjectFunc {
 	return func(ctx context.Context, obj runtime.Object) error {
 		return f(ctx, scaleFromRC(obj.(*api.ReplicationController)))

pkg/registry/core/resourcequota/storage/storage.go

@@ -98,3 +98,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/core/service/storage/storage.go

@@ -178,6 +178,10 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 	return r.store.Update(ctx, name, objInfo, createValidation, updateValidation, false, options)
 }
 
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}
+
 // GetResetFields implements rest.ResetFieldsStrategy
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()

pkg/registry/flowcontrol/flowschema/storage/storage.go

@@ -97,3 +97,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/flowcontrol/prioritylevelconfiguration/storage/storage.go

@@ -97,3 +97,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/networking/ingress/storage/storage.go

@@ -96,3 +96,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/policy/poddisruptionbudget/storage/storage.go

@@ -93,3 +93,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

pkg/registry/storage/volumeattachment/storage/storage.go

@@ -101,3 +101,7 @@ func (r *StatusREST) Update(ctx context.Context, name string, objInfo rest.Updat
 func (r *StatusREST) GetResetFields() map[fieldpath.APIVersion]*fieldpath.Set {
 	return r.store.GetResetFields()
 }
+
+func (r *StatusREST) ConvertToTable(ctx context.Context, object runtime.Object, tableOptions runtime.Object) (*metav1.Table, error) {
+	return r.store.ConvertToTable(ctx, object, tableOptions)
+}

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/customresource_handler.go

@@ -878,7 +878,13 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 			requestScopes[v.Name] = &reqScope
 		}
 
-		// override scaleSpec subresource values
+		scaleColumns, err := getScaleColumnsForVersion(crd, v.Name)
+		if err != nil {
+			return nil, fmt.Errorf("the server could not properly serve the CR scale subresource columns %w", err)
+		}
+		scaleTable, _ := tableconvertor.New(scaleColumns)
+
+		// override scale subresource values
 		// shallow copy
 		scaleScope := *requestScopes[v.Name]
 		scaleConverter := scale.NewScaleConverter()
@@ -889,6 +895,7 @@ func (r *crdHandler) getOrCreateServingInfoFor(uid types.UID, name string) (*crd
 			Namer:         meta.NewAccessor(),
 			ClusterScoped: clusterScoped,
 		}
+		scaleScope.TableConvertor = scaleTable
 
 		if utilfeature.DefaultFeatureGate.Enabled(features.ServerSideApply) && subresources != nil && subresources.Scale != nil {
 			scaleScope, err = scopeWithFieldManager(

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/helpers.go

@@ -18,6 +18,7 @@ package apiserver
 
 import (
 	"fmt"
+
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
@@ -37,6 +38,42 @@ func getColumnsForVersion(crd *apiextensionsv1.CustomResourceDefinition, version
 	return nil, fmt.Errorf("version %s not found in apiextensionsv1.CustomResourceDefinition: %v", version, crd.Name)
 }
 
+// getScaleColumnsForVersion returns 2 columns for the desired and actual number of replicas.
+func getScaleColumnsForVersion(crd *apiextensionsv1.CustomResourceDefinition, version string) ([]apiextensionsv1.CustomResourceColumnDefinition, error) {
+	for _, v := range crd.Spec.Versions {
+		if version != v.Name {
+			continue
+		}
+		var cols []apiextensionsv1.CustomResourceColumnDefinition
+		if v.Subresources != nil && v.Subresources.Scale != nil {
+			if v.Subresources.Scale.SpecReplicasPath != "" {
+				cols = append(cols, apiextensionsv1.CustomResourceColumnDefinition{
+					Name:        "Desired",
+					Type:        "integer",
+					Description: "Number of desired replicas",
+					JSONPath:    ".spec.replicas",
+				})
+			}
+			if v.Subresources.Scale.StatusReplicasPath != "" {
+				cols = append(cols, apiextensionsv1.CustomResourceColumnDefinition{
+					Name:        "Available",
+					Type:        "integer",
+					Description: "Number of actual replicas",
+					JSONPath:    ".status.replicas",
+				})
+			}
+		}
+		cols = append(cols, apiextensionsv1.CustomResourceColumnDefinition{
+			Name:        "Age",
+			Type:        "date",
+			Description: swaggerMetadataDescriptions["creationTimestamp"],
+			JSONPath:    ".metadata.creationTimestamp",
+		})
+		return cols, nil
+	}
+	return nil, fmt.Errorf("version %s not found in apiextensionsv1.CustomResourceDefinition: %v", version, crd.Name)
+}
+
 // serveDefaultColumnsIfEmpty applies logically defaulting to columns, if the input columns is empty.
 // NOTE: in this way, the newly logically-defaulted columns is not pointing to the original CRD object.
 // One cannot mutate the original CRD columns using the logically-defaulted columns. Please iterate through

staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/tableconvertor/tableconvertor.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	metatable "k8s.io/apimachinery/pkg/api/meta/table"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apiserver/pkg/registry/rest"
 	"k8s.io/client-go/util/jsonpath"
@@ -104,8 +105,16 @@ func (c *convertor) ConvertToTable(ctx context.Context, obj runtime.Object, tabl
 		cells := make([]interface{}, 1, 1+len(c.additionalColumns))
 		cells[0] = name
 		customHeaders := c.headers[1:]
+		us, ok := obj.(runtime.Unstructured)
+		if !ok {
+			m, err := runtime.DefaultUnstructuredConverter.ToUnstructured(obj)
+			if err != nil {
+				return nil, err
+			}
+			us = &unstructured.Unstructured{Object: m}
+		}
 		for i, column := range c.additionalColumns {
-			results, err := column.FindResults(obj.(runtime.Unstructured).UnstructuredContent())
+			results, err := column.FindResults(us.UnstructuredContent())
 			if err != nil || len(results) == 0 || len(results[0]) == 0 {
 				cells = append(cells, nil)
 				continue

test/integration/apiserver/apiserver_test.go

@@ -1368,6 +1368,226 @@ func TestAPICRDProtobuf(t *testing.T) {
 	}
 }
 
+func TestGetSubresourcesAsTables(t *testing.T) {
+	testNamespace := "test-transform"
+	tearDown, config, _, err := fixtures.StartDefaultServer(t)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer tearDown()
+
+	s, clientset, closeFn := setup(t)
+	defer closeFn()
+	fmt.Printf("%#v\n", clientset)
+
+	apiExtensionClient, err := apiextensionsclient.NewForConfig(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dynamicClient, err := dynamic.NewForConfig(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fooWithSubresourceCRD := &apiextensionsv1.CustomResourceDefinition{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "foosubs.cr.bar.com",
+		},
+		Spec: apiextensionsv1.CustomResourceDefinitionSpec{
+			Group: "cr.bar.com",
+			Scope: apiextensionsv1.NamespaceScoped,
+			Names: apiextensionsv1.CustomResourceDefinitionNames{
+				Plural: "foosubs",
+				Kind:   "FooSub",
+			},
+			Versions: []apiextensionsv1.CustomResourceDefinitionVersion{
+				{
+					Name:    "v1",
+					Served:  true,
+					Storage: true,
+					Schema: &apiextensionsv1.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensionsv1.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensionsv1.JSONSchemaProps{
+								"spec": {
+									Type: "object",
+									Properties: map[string]apiextensionsv1.JSONSchemaProps{
+										"replicas": {
+											Type: "integer",
+										},
+									},
+								},
+								"status": {
+									Type: "object",
+									Properties: map[string]apiextensionsv1.JSONSchemaProps{
+										"replicas": {
+											Type: "integer",
+										},
+									},
+								},
+							},
+						},
+					},
+					Subresources: &apiextensionsv1.CustomResourceSubresources{
+						Status: &apiextensionsv1.CustomResourceSubresourceStatus{},
+						Scale: &apiextensionsv1.CustomResourceSubresourceScale{
+							SpecReplicasPath:   ".spec.replicas",
+							StatusReplicasPath: ".status.replicas",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	fooWithSubresourceCRD, err = fixtures.CreateNewV1CustomResourceDefinition(fooWithSubresourceCRD, apiExtensionClient, dynamicClient)
+	if err != nil {
+		t.Fatal(err)
+	}
+	subresourcesCrdGVR := schema.GroupVersionResource{Group: fooWithSubresourceCRD.Spec.Group, Version: fooWithSubresourceCRD.Spec.Versions[0].Name, Resource: "foosubs"}
+	subresourcesCrclient := dynamicClient.Resource(subresourcesCrdGVR).Namespace(testNamespace)
+
+	testcases := []struct {
+		name        string
+		accept      string
+		object      func(*testing.T) (metav1.Object, string, string)
+		subresource string
+	}{
+		{
+			name:   "v1 verify status subresource returns a table for CRDs",
+			accept: "application/json;as=Table;g=meta.k8s.io;v=v1",
+			object: func(t *testing.T) (metav1.Object, string, string) {
+				cr, err := subresourcesCrclient.Create(context.TODO(), &unstructured.Unstructured{Object: map[string]interface{}{"apiVersion": "cr.bar.com/v1", "kind": "FooSub", "metadata": map[string]interface{}{"name": "test-1"}, "spec": map[string]interface{}{"replicas": 2}}}, metav1.CreateOptions{})
+				if err != nil {
+					t.Fatalf("unable to create cr: %v", err)
+				}
+				return cr, subresourcesCrdGVR.Group, "foosubs"
+			},
+			subresource: "status",
+		},
+		{
+			name:   "v1 verify scale subresource returns a table for CRDs",
+			accept: "application/json;as=Table;g=meta.k8s.io;v=v1",
+			object: func(t *testing.T) (metav1.Object, string, string) {
+				cr, err := subresourcesCrclient.Create(context.TODO(), &unstructured.Unstructured{Object: map[string]interface{}{"apiVersion": "cr.bar.com/v1", "kind": "FooSub", "metadata": map[string]interface{}{"name": "test-2"}, "spec": map[string]interface{}{"replicas": 2}}}, metav1.CreateOptions{})
+				if err != nil {
+					t.Fatalf("unable to create cr: %v", err)
+				}
+				return cr, subresourcesCrdGVR.Group, "foosubs"
+			},
+			subresource: "scale",
+		},
+		{
+			name:   "verify status subresource returns a table for replicationcontrollers",
+			accept: "application/json;as=Table;g=meta.k8s.io;v=v1",
+			object: func(t *testing.T) (metav1.Object, string, string) {
+				rc := &v1.ReplicationController{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "replicationcontroller-1",
+					},
+					Spec: v1.ReplicationControllerSpec{
+						Replicas: int32Ptr(2),
+						Selector: map[string]string{
+							"label": "test-label",
+						},
+						Template: &v1.PodTemplateSpec{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"label": "test-label",
+								},
+							},
+							Spec: v1.PodSpec{
+								Containers: []v1.Container{
+									{Name: "test-name", Image: "nonexistant-image"},
+								},
+							},
+						},
+					},
+				}
+				rc, err := clientset.CoreV1().ReplicationControllers(testNamespace).Create(context.TODO(), rc, metav1.CreateOptions{})
+				if err != nil {
+					t.Fatalf("unable to create replicationcontroller: %v", err)
+				}
+				return rc, "", "replicationcontrollers"
+			},
+			subresource: "status",
+		},
+		{
+			name:   "verify scale subresource returns a table for replicationcontrollers",
+			accept: "application/json;as=Table;g=meta.k8s.io;v=v1",
+			object: func(t *testing.T) (metav1.Object, string, string) {
+				rc := &v1.ReplicationController{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "replicationcontroller-2",
+					},
+					Spec: v1.ReplicationControllerSpec{
+						Replicas: int32Ptr(2),
+						Selector: map[string]string{
+							"label": "test-label",
+						},
+						Template: &v1.PodTemplateSpec{
+							ObjectMeta: metav1.ObjectMeta{
+								Labels: map[string]string{
+									"label": "test-label",
+								},
+							},
+							Spec: v1.PodSpec{
+								Containers: []v1.Container{
+									{Name: "test-name", Image: "nonexistant-image"},
+								},
+							},
+						},
+					},
+				}
+				rc, err := clientset.CoreV1().ReplicationControllers(testNamespace).Create(context.TODO(), rc, metav1.CreateOptions{})
+				if err != nil {
+					t.Fatalf("unable to create replicationcontroller: %v", err)
+				}
+				return rc, "", "replicationcontrollers"
+			},
+			subresource: "scale",
+		},
+	}
+
+	for i := range testcases {
+		tc := testcases[i]
+		t.Run(tc.name, func(t *testing.T) {
+			obj, group, resource := tc.object(t)
+
+			cfg := dynamic.ConfigFor(config)
+			if len(group) == 0 {
+				cfg = dynamic.ConfigFor(&restclient.Config{Host: s.URL})
+				cfg.APIPath = "/api"
+			} else {
+				cfg.APIPath = "/apis"
+			}
+			cfg.GroupVersion = &schema.GroupVersion{Group: group, Version: "v1"}
+
+			client, err := restclient.RESTClientFor(cfg)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			res := client.Get().
+				Resource(resource).NamespaceIfScoped(obj.GetNamespace(), len(obj.GetNamespace()) > 0).
+				SetHeader("Accept", tc.accept).
+				Name(obj.GetName()).
+				SubResource(tc.subresource).
+				Do(context.TODO())
+
+			resObj, err := res.Get()
+			if err != nil {
+				t.Fatalf("failed to retrieve object from response: %v", err)
+			}
+			actualKind := resObj.GetObjectKind().GroupVersionKind().Kind
+			if actualKind != "Table" {
+				t.Fatalf("Expected Kind 'Table', got '%v'", actualKind)
+			}
+		})
+	}
+}
+
 func TestTransform(t *testing.T) {
 	testNamespace := "test-transform"
 	tearDown, config, _, err := fixtures.StartDefaultServer(t)
@@ -2483,3 +2703,7 @@ func assertManagedFields(t *testing.T, obj *unstructured.Unstructured) {
 		t.Errorf("unexpected empty managed fields in object: %v", obj)
 	}
 }
+
+func int32Ptr(i int32) *int32 {
+	return &i
+}