✨ Allow customizing generated webhook K8s Service

Allow customizing the webhook K8s Service's name, namespace, and port.

## example usage

Look for the new `serviceName`, `serviceNamespace`, and `servicePort` fields.

```
❯ GOBIN=(pwd)/bin go install ./cmd/*

❯ ./bin/controller-gen webhook -w

Webhook

+kubebuilder:webhook:admissionReviewVersions=<[]string>,failurePolicy=<string>,groups=<[]string>[,matchPolicy=<string>],mutating=<bool>,name=<string>[,path=<string>][,reinvocationPolicy=<string>],resources=<[]string>[,serviceName=<string>][,serviceNamespace=<string>][,servicePort=<int>][,sideEffects=<string>][,timeoutSeconds=<int>][,url=<string>],verbs=<[]string>,versions=<[]string>[,webhookVersions=<[]string>]  package  specifies how a webhook should be served.

...
```

contributes to #865

Author: davidxia

pkg/webhook/parser.go

@@ -38,8 +38,11 @@ import (
 
 // The default {Mutating,Validating}WebhookConfiguration version to generate.
 const (
-	v1                    = "v1"
-	defaultWebhookVersion = v1
+	v1                      = "v1"
+	defaultWebhookVersion   = v1
+	defaultServiceName      = "webhook-service"
+	defaultServiceNamespace = "system"
+	defaultServicePort      = 443
 )
 
 var (
@@ -118,6 +121,12 @@ type Config struct {
 	// Name indicates the name of this webhook configuration. Should be a domain with at least three segments separated by dots
 	Name string
 
+	// ServiceName indicates the name of the K8s Service the webhook uses.
+	ServiceName string `marker:"serviceName,optional"`
+
+	// ServiceNamespace indicates the namespace of the K8s Service the webhook uses.
+	ServiceNamespace string `marker:"serviceNamespace,optional"`
+
 	// Path specifies that path that the API server should connect to this webhook on. Must be
 	// prefixed with a '/validate-' or '/mutate-' depending on the type, and followed by
 	// $GROUP-$VERSION-$KIND where all values are lower-cased and the periods in the group
@@ -126,6 +135,9 @@ type Config struct {
 	// /validate-batch-tutorial-kubebuilder-io-v1-cronjob
 	Path string `marker:"path,optional"`
 
+	// ServicePort indicates the port of the K8s Service the webhook uses
+	ServicePort int32 `marker:"servicePort,optional"`
+
 	// WebhookVersions specifies the target API versions of the {Mutating,Validating}WebhookConfiguration objects
 	// itself to generate. The only supported value is v1. Defaults to v1.
 	WebhookVersions []string `marker:"webhookVersions,optional"`
@@ -318,11 +330,29 @@ func (c Config) clientConfig() (admissionregv1.WebhookClientConfig, error) {
 
 	path := c.Path
 	if path != "" {
+		var name, namespace string
+		var port *int32
+
+		if c.ServiceName != "" {
+			name = c.ServiceName
+		} else {
+			name = defaultServiceName
+		}
+		if c.ServiceNamespace != "" {
+			namespace = c.ServiceNamespace
+		} else {
+			namespace = defaultServiceNamespace
+		}
+		if c.ServicePort != 0 {
+			port = &c.ServicePort
+		}
+
 		return admissionregv1.WebhookClientConfig{
 			Service: &admissionregv1.ServiceReference{
-				Name:      "webhook-service",
-				Namespace: "system",
+				Name:      name,
+				Namespace: namespace,
 				Path:      &path,
+				Port:      port,
 			},
 		}, nil
 	}