move webhooks to internal

Makefile

@@ -365,7 +365,7 @@ generate-manifests-core: $(CONTROLLER_GEN) $(KUSTOMIZE)
 	$(CONTROLLER_GEN) \
 		paths=./api/... \
 		paths=./controllers/... \
-		paths=./webhooks/... \
+		paths=./internal/webhooks/... \
 		paths=./$(EXP_DIR)/api/... \
 		paths=./$(EXP_DIR)/controllers/... \
 		paths=./$(EXP_DIR)/addons/api/... \

internal/webhooks/doc.go

@@ -0,0 +1,18 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package webhooks contains external webhook implementations for some of our API types.
+package webhooks

webhooks/alias.go

@@ -0,0 +1,41 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package webhooks
+
+import (
+	clusterwebhooks "sigs.k8s.io/cluster-api/webhooks/internal/webhooks"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// Cluster implements a validating and defaulting webhook for Cluster.
+type Cluster struct {
+	Client client.Reader
+}
+
+// SetupWebhookWithManager sets up Cluster webhooks.
+func (webhook *Cluster) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return (&clusterwebhooks.Cluster{}).SetupWebhookWithManager(mgr)
+}
+
+// ClusterClass implements a validation and defaulting webhook for ClusterClass.
+type ClusterClass struct{}
+
+// SetupWebhookWithManager sets up ClusterClass webhooks.
+func (webhook *ClusterClass) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return (&clusterwebhooks.ClusterClass{}).SetupWebhookWithManager(mgr)
+}