apimachinery: handle duplicated and conflicting type registration

staging/src/k8s.io/apimachinery/pkg/runtime/scheme.go

@@ -190,7 +190,17 @@ func (s *Scheme) AddKnownTypeWithName(gvk schema.GroupVersionKind, obj Object) {
 		panic("All types must be pointers to structs.")
 	}
 
+	if oldT, found := s.gvkToType[gvk]; found && oldT != t {
+		panic(fmt.Sprintf("Double registration of different types for %v: old=%v.%v, new=%v.%v", gvk, oldT.PkgPath(), oldT.Name(), t.PkgPath(), t.Name()))
+	}
+
 	s.gvkToType[gvk] = t
+
+	for _, existingGvk := range s.typeToGVK[t] {
+		if existingGvk == gvk {
+			return
+		}
+	}
 	s.typeToGVK[t] = append(s.typeToGVK[t], gvk)
 }
 

staging/src/k8s.io/apimachinery/pkg/runtime/scheme_test.go

@@ -548,6 +548,79 @@ func TestKnownTypes(t *testing.T) {
 	}
 }
 
+func TestAddKnownTypesIdemPotent(t *testing.T) {
+	s := runtime.NewScheme()
+
+	gv := schema.GroupVersion{Group: "foo", Version: "v1"}
+	s.AddKnownTypes(gv, &InternalSimple{})
+	s.AddKnownTypes(gv, &InternalSimple{})
+	if len(s.KnownTypes(gv)) != 1 {
+		t.Errorf("expected only one %v type after double registration", gv)
+	}
+	if len(s.AllKnownTypes()) != 1 {
+		t.Errorf("expected only one type after double registration")
+	}
+
+	s.AddKnownTypeWithName(gv.WithKind("InternalSimple"), &InternalSimple{})
+	s.AddKnownTypeWithName(gv.WithKind("InternalSimple"), &InternalSimple{})
+	if len(s.KnownTypes(gv)) != 1 {
+		t.Errorf("expected only one %v type after double registration with custom name", gv)
+	}
+	if len(s.AllKnownTypes()) != 1 {
+		t.Errorf("expected only one type after double registration with custom name")
+	}
+
+	s.AddUnversionedTypes(gv, &InternalSimple{})
+	if len(s.KnownTypes(gv)) != 1 {
+		t.Errorf("expected only one %v type after double registration with custom name", gv)
+	}
+	if len(s.AllKnownTypes()) != 1 {
+		t.Errorf("expected only one type after double registration with custom name")
+	}
+
+	kinds, _, err := s.ObjectKinds(&InternalSimple{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(kinds) != 1 {
+		t.Errorf("expected only one kind for InternalSimple after double registration", gv)
+	}
+}
+
+func TestConflictingAddKnownTypes(t *testing.T) {
+	s := runtime.NewScheme()
+	gv := schema.GroupVersion{Group: "foo", Version: "v1"}
+
+	panicked := make(chan bool)
+	go func() {
+		defer func() {
+			if recover() != nil {
+				panicked <- true
+			}
+		}()
+		s.AddKnownTypeWithName(gv.WithKind("InternalSimple"), &InternalSimple{})
+		s.AddKnownTypeWithName(gv.WithKind("InternalSimple"), &ExternalSimple{})
+		panicked <- false
+	}()
+	if !<-panicked {
+		t.Errorf("Expected AddKnownTypesWithName to panic with conflicting type registrations")
+	}
+
+	go func() {
+		defer func() {
+			if recover() != nil {
+				panicked <- true
+			}
+		}()
+		s.AddUnversionedTypes(gv, &InternalSimple{})
+		s.AddUnversionedTypes(gv, &InternalSimple{})
+		panicked <- false
+	}()
+	if !<-panicked {
+		t.Errorf("Expected AddUnversionedTypes to panic with conflicting type registrations")
+	}
+}
+
 func TestConvertToVersionBasic(t *testing.T) {
 	s := GetTestScheme()
 	tt := &TestType1{A: "I'm not a pointer object"}

staging/src/k8s.io/apiserver/pkg/apis/apiserver/register.go

@@ -17,7 +17,6 @@ limitations under the License.
 package apiserver
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
@@ -47,6 +46,5 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
 		&AdmissionConfiguration{},
 	)
-	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }

staging/src/k8s.io/apiserver/pkg/apis/example/register.go

@@ -17,7 +17,6 @@ limitations under the License.
 package example
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
@@ -48,6 +47,5 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
 		&Pod{},
 	)
-	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }

staging/src/k8s.io/apiserver/pkg/storage/etcd/etcd_helper_test.go

@@ -77,7 +77,6 @@ func testScheme(t *testing.T) (*runtime.Scheme, serializer.CodecFactory) {
 	scheme := runtime.NewScheme()
 	scheme.Log(t)
 	scheme.AddKnownTypes(schema.GroupVersion{Version: runtime.APIVersionInternal}, &storagetesting.TestResource{})
-	scheme.AddKnownTypes(schema.GroupVersion{Version: runtime.APIVersionInternal}, &storagetesting.TestResource{})
 	example.AddToScheme(scheme)
 	examplev1.AddToScheme(scheme)
 	if err := scheme.AddConversionFuncs(

staging/src/k8s.io/kube-aggregator/pkg/apis/apiregistration/register.go

@@ -17,12 +17,8 @@ limitations under the License.
 package apiregistration
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
-
-	// we register here until we separate our scheme, which requires updates to client gen
-	kapi "k8s.io/client-go/pkg/api"
 )
 
 const GroupName = "apiregistration.k8s.io"
@@ -50,11 +46,6 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 	scheme.AddKnownTypes(SchemeGroupVersion,
 		&APIService{},
 		&APIServiceList{},
-
-		&kapi.ListOptions{},
-		&metav1.DeleteOptions{},
-		&metav1.GetOptions{},
 	)
-	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }

staging/src/k8s.io/sample-apiserver/pkg/apis/wardle/register.go

@@ -17,7 +17,6 @@ limitations under the License.
 package wardle
 
 import (
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
@@ -48,6 +47,5 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 		&Flunder{},
 		&FlunderList{},
 	)
-	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }