refactor factory to support fake openapiv3

staging/src/k8s.io/kubectl/pkg/cmd/explain/explain.go

@@ -24,7 +24,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
-	"k8s.io/client-go/discovery"
+	openapiclient "k8s.io/client-go/openapi"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/explain"
 	explainv2 "k8s.io/kubectl/pkg/explain/v2"
@@ -74,7 +74,7 @@ type ExplainOptions struct {
 	OutputFormat string
 
 	// Client capable of fetching openapi documents from the user's cluster
-	DiscoveryClient discovery.DiscoveryInterface
+	OpenAPIV3Client openapiclient.Client
 }
 
 func NewExplainOptions(parent string, streams genericclioptions.IOStreams) *ExplainOptions {
@@ -125,13 +125,12 @@ func (o *ExplainOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []
 		return err
 	}
 
-	// Only openapi v3 needs the discovery client.
+	// Only openapi v3 needs the openapiv3client
 	if o.EnableOpenAPIV3 {
-		discoveryClient, err := f.ToDiscoveryClient()
+		o.OpenAPIV3Client, err = f.OpenAPIV3Client()
 		if err != nil {
 			return err
 		}
-		o.DiscoveryClient = discoveryClient
 	}
 
 	o.args = args
@@ -176,7 +175,7 @@ func (o *ExplainOptions) Run() error {
 		return explainv2.PrintModelDescription(
 			fieldsPath,
 			o.Out,
-			o.DiscoveryClient.OpenAPIV3(),
+			o.OpenAPIV3Client,
 			fullySpecifiedGVR,
 			recursive,
 			o.OutputFormat,

staging/src/k8s.io/kubectl/pkg/cmd/testing/fake.go

@@ -38,6 +38,8 @@ import (
 	"k8s.io/client-go/dynamic"
 	fakedynamic "k8s.io/client-go/dynamic/fake"
 	"k8s.io/client-go/kubernetes"
+	openapiclient "k8s.io/client-go/openapi"
+	"k8s.io/client-go/openapi/openapitest"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/rest/fake"
 	"k8s.io/client-go/restmapper"
@@ -418,6 +420,7 @@ type TestFactory struct {
 
 	UnstructuredClientForMappingFunc resource.FakeClientFunc
 	OpenAPISchemaFunc                func() (openapi.Resources, error)
+	OpenAPIV3ClientFunc              func() (openapiclient.Client, error)
 }
 
 // NewTestFactory returns an initialized TestFactory instance
@@ -533,6 +536,13 @@ func (f *TestFactory) OpenAPISchema() (openapi.Resources, error) {
 	return openapitesting.EmptyResources{}, nil
 }
 
+func (f *TestFactory) OpenAPIV3Client() (openapiclient.Client, error) {
+	if f.OpenAPIV3ClientFunc != nil {
+		return f.OpenAPIV3ClientFunc()
+	}
+	return openapitest.NewFakeClient(), nil
+}
+
 // NewBuilder returns an initialized resource.Builder instance
 func (f *TestFactory) NewBuilder() *resource.Builder {
 	return resource.NewFakeBuilder(

staging/src/k8s.io/kubectl/pkg/cmd/util/factory.go

@@ -22,6 +22,7 @@ import (
 	"k8s.io/cli-runtime/pkg/resource"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	openapiclient "k8s.io/client-go/openapi"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/kubectl/pkg/util/openapi"
 	"k8s.io/kubectl/pkg/validation"
@@ -63,4 +64,7 @@ type Factory interface {
 	Validator(validationDirective string) (validation.Schema, error)
 	// OpenAPISchema returns the parsed openapi schema definition
 	OpenAPISchema() (openapi.Resources, error)
+	// OpenAPIV3Schema returns a client for fetching parsed schemas for
+	// any group version
+	OpenAPIV3Client() (openapiclient.Client, error)
 }

staging/src/k8s.io/kubectl/pkg/cmd/util/factory_client_access.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	openapiclient "k8s.io/client-go/openapi"
 	"k8s.io/client-go/openapi/cached"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
@@ -211,3 +212,12 @@ func (f *factoryImpl) openAPIGetter() discovery.OpenAPISchemaInterface {
 
 	return f.oapi
 }
+
+func (f *factoryImpl) OpenAPIV3Client() (openapiclient.Client, error) {
+	discovery, err := f.clientGetter.ToDiscoveryClient()
+	if err != nil {
+		return nil, err
+	}
+
+	return discovery.OpenAPIV3(), nil
+}