Generate webhook for WatcherApplier

Below is the command used to generate the same:
```
operator-sdk create webhook --group watcher --version v1beta1 --kind WatcherApplier --programmatic-validation --defaulting
```

Signed-off-by: Chandan Kumar <[email protected]>

PROJECT

@@ -59,4 +59,8 @@ resources:
   kind: WatcherApplier
   path: github.com/openstack-k8s-operators/watcher-operator/api/v1beta1
   version: v1beta1
+  webhooks:
+    defaulting: true
+    validation: true
+    webhookVersion: v1
 version: "3"

api/v1beta1/watcherapplier_webhook.go

@@ -0,0 +1,75 @@
+/*
+Copyright 2024.
+
+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 v1beta1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime"
+	ctrl "sigs.k8s.io/controller-runtime"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/webhook"
+)
+
+// log is for logging in this package.
+var watcherapplierlog = logf.Log.WithName("watcherapplier-resource")
+
+func (r *WatcherApplier) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewWebhookManagedBy(mgr).
+		For(r).
+		Complete()
+}
+
+// TODO(user): EDIT THIS FILE!  THIS IS SCAFFOLDING FOR YOU TO OWN!
+
+//+kubebuilder:webhook:path=/mutate-watcher-openstack-org-v1beta1-watcherapplier,mutating=true,failurePolicy=fail,sideEffects=None,groups=watcher.openstack.org,resources=watcherappliers,verbs=create;update,versions=v1beta1,name=mwatcherapplier.kb.io,admissionReviewVersions=v1
+
+var _ webhook.Defaulter = &WatcherApplier{}
+
+// Default implements webhook.Defaulter so a webhook will be registered for the type
+func (r *WatcherApplier) Default() {
+	watcherapplierlog.Info("default", "name", r.Name)
+
+	// TODO(user): fill in your defaulting logic.
+}
+
+// TODO(user): change verbs to "verbs=create;update;delete" if you want to enable deletion validation.
+//+kubebuilder:webhook:path=/validate-watcher-openstack-org-v1beta1-watcherapplier,mutating=false,failurePolicy=fail,sideEffects=None,groups=watcher.openstack.org,resources=watcherappliers,verbs=create;update,versions=v1beta1,name=vwatcherapplier.kb.io,admissionReviewVersions=v1
+
+var _ webhook.Validator = &WatcherApplier{}
+
+// ValidateCreate implements webhook.Validator so a webhook will be registered for the type
+func (r *WatcherApplier) ValidateCreate() error {
+	watcherapplierlog.Info("validate create", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object creation.
+	return nil
+}
+
+// ValidateUpdate implements webhook.Validator so a webhook will be registered for the type
+func (r *WatcherApplier) ValidateUpdate(old runtime.Object) error {
+	watcherapplierlog.Info("validate update", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object update.
+	return nil
+}
+
+// ValidateDelete implements webhook.Validator so a webhook will be registered for the type
+func (r *WatcherApplier) ValidateDelete() error {
+	watcherapplierlog.Info("validate delete", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object deletion.
+	return nil
+}

api/v1beta1/webhook_suite_test.go

@@ -108,6 +108,9 @@ var _ = BeforeSuite(func() {
 	err = (&WatcherDecisionEngine{}).SetupWebhookWithManager(mgr)
 	Expect(err).NotTo(HaveOccurred())
 
+	err = (&WatcherApplier{}).SetupWebhookWithManager(mgr)
+	Expect(err).NotTo(HaveOccurred())
+
 	//+kubebuilder:scaffold:webhook
 
 	go func() {