Merge pull request #54535 from nikhita/apiextensions-typed-client

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

apiextensions/examples: add typed client

It was discussed in https://github.com/kubernetes/kubernetes/pull/52753#issuecomment-337840762 to add a typed client example to apiextensions-apiserver and remove the controller part.

For an example controller, we have [`k8s.io/sample-controller`](https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/sample-controller) now.

**Release note**:

```release-note
NONE
```

Kubernetes-commit: 175af4c3c4797786c5344d334de400f640a9e509

pkg/apis/samplecontroller/v1alpha1/register.go

@@ -17,7 +17,6 @@ limitations under the License.
 package v1alpha1
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 
@@ -27,31 +26,26 @@ import (
 // SchemeGroupVersion is group version used to register these objects
 var SchemeGroupVersion = schema.GroupVersion{Group: samplecontroller.GroupName, Version: "v1alpha1"}
 
+// Kind takes an unqualified kind and returns back a Group qualified GroupKind
+func Kind(kind string) schema.GroupKind {
+	return SchemeGroupVersion.WithKind(kind).GroupKind()
+}
+
 // Resource takes an unqualified resource and returns a Group qualified GroupResource
 func Resource(resource string) schema.GroupResource {
 	return SchemeGroupVersion.WithResource(resource).GroupResource()
 }
 
 var (
-	// localSchemeBuilder and AddToScheme will stay in k8s.io/kubernetes.
-	SchemeBuilder      runtime.SchemeBuilder
-	localSchemeBuilder = &SchemeBuilder
-	AddToScheme        = localSchemeBuilder.AddToScheme
+	SchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)
+	AddToScheme   = SchemeBuilder.AddToScheme
 )
 
-func init() {
-	// We only register manually written functions here. The registration of the
-	// generated functions takes place in the generated files. The separation
-	// makes the code compile even when the generated files are missing.
-	localSchemeBuilder.Register(addKnownTypes)
-}
-
-// Adds the list of known types to api.Scheme.
+// Adds the list of known types to Scheme.
 func addKnownTypes(scheme *runtime.Scheme) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
 		&Foo{},
 		&FooList{},
 	)
-	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }

pkg/apis/samplecontroller/v1alpha1/types.go

@@ -23,7 +23,6 @@ import (
 // +genclient
 // +genclient:noStatus
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
-// +resource:path=foo
 
 // Foo is a specification for a Foo resource
 type Foo struct {
@@ -46,7 +45,6 @@ type FooStatus struct {
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
-// +resource:path=foos
 
 // FooList is a list of Foo resources
 type FooList struct {