✨ Webhooks for external APIs

pkg/plugins/golang/options.go

@@ -90,7 +90,8 @@ func (opts Options) UpdateResource(res *resource.Resource, c config.Config) {
 
 	if opts.DoDefaulting || opts.DoValidation || opts.DoConversion {
 		//nolint:staticcheck
-		res.Path = resource.APIPackagePath(c.GetRepository(), res.Group, res.Version, c.IsMultiGroup())
+		loadedRes, _ := c.GetResource(res.GVK)
+		res.Path = loadedRes.Path
 
 		res.Webhooks.WebhookVersion = "v1"
 		if opts.DoDefaulting {

pkg/plugins/golang/v4/scaffolds/internal/templates/api/webhook.go

@@ -40,6 +40,10 @@ type Webhook struct { // nolint:maligned
 	// Define value for AdmissionReviewVersions marker
 	AdmissionReviewVersions string
 
+	// If the webhook is for an external resource. External resources need to be
+	// imported.
+	ExternalAPI bool
+
 	Force bool
 }
 
@@ -97,16 +101,27 @@ import (
 	{{- if .Resource.HasValidationWebhook }}
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 	{{- end }}
+	{{- if .ExternalAPI }}
+	{{ .Resource.ImportAlias }} "{{ .Resource.Path }}"
+	{{- end }}
 )
 
 // nolint:unused
 // log is for logging in this package.
 var {{ lower .Resource.Kind }}log = logf.Log.WithName("{{ lower .Resource.Kind }}-resource")
 
 // SetupWebhookWithManager will setup the manager to manage the webhooks.
+{{- if .ExternalAPI }}
+func SetupWebhookFor{{ .Resource.Kind }}WithManager(mgr ctrl.Manager) error {
+{{- else }}
 func (r *{{ .Resource.Kind }}) SetupWebhookWithManager(mgr ctrl.Manager) error {
+{{- end }}
 	return ctrl.NewWebhookManagedBy(mgr).
+		{{- if .ExternalAPI }}
+		For(&{{ .Resource.ImportAlias }}.{{ .Resource.Kind }}{}).
+		{{- else }}
 		For(r).
+		{{- end }}
 		{{- if .Resource.HasValidationWebhook }}
 		WithValidator(&{{ .Resource.Kind }}CustomValidator{}).
 		{{- end }}
@@ -137,7 +152,11 @@ var _ webhook.CustomDefaulter = &{{ .Resource.Kind }}CustomDefaulter{}
 
 // Default implements webhook.CustomDefaulter so a webhook will be registered for the Kind {{ .Resource.Kind }}.
 func (d *{{ .Resource.Kind }}CustomDefaulter) Default(ctx context.Context, obj runtime.Object) error {
+	{{- if .ExternalAPI }}
+	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.ImportAlias }}.{{ .Resource.Kind }})
+	{{- else }}
 	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.Kind }})
+	{{- end }}
 	if !ok {
 		return fmt.Errorf("expected an {{ .Resource.Kind }} object but got %T", obj)
 	}	
@@ -170,7 +189,11 @@ var _ webhook.CustomValidator = &{{ .Resource.Kind }}CustomValidator{}
 
 // ValidateCreate implements webhook.CustomValidator so a webhook will be registered for the type {{ .Resource.Kind }}.
 func (v *{{ .Resource.Kind }}CustomValidator) ValidateCreate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
+	{{- if .ExternalAPI }}
+	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.ImportAlias }}.{{ .Resource.Kind }})
+	{{- else }}
 	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.Kind }})
+	{{- end }}
 	if !ok {
 		return nil, fmt.Errorf("expected a {{ .Resource.Kind }} object but got %T", obj)
 	}
@@ -183,7 +206,11 @@ func (v *{{ .Resource.Kind }}CustomValidator) ValidateCreate(ctx context.Context
 
 // ValidateUpdate implements webhook.CustomValidator so a webhook will be registered for the type {{ .Resource.Kind }}.
 func (v *{{ .Resource.Kind }}CustomValidator) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) (admission.Warnings, error) {
+	{{- if .ExternalAPI }}
+	{{ lower .Resource.Kind }}, ok := newObj.(*{{ .Resource.ImportAlias }}.{{ .Resource.Kind }})
+	{{- else }}
 	{{ lower .Resource.Kind }}, ok := newObj.(*{{ .Resource.Kind }})
+	{{- end }}
 	if !ok {
 		return nil, fmt.Errorf("expected a {{ .Resource.Kind }} object but got %T", newObj)
 	}
@@ -196,7 +223,11 @@ func (v *{{ .Resource.Kind }}CustomValidator) ValidateUpdate(ctx context.Context
 
 // ValidateDelete implements webhook.CustomValidator so a webhook will be registered for the type {{ .Resource.Kind }}.
 func (v *{{ .Resource.Kind }}CustomValidator) ValidateDelete(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
+	{{- if .ExternalAPI }}
+	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.ImportAlias }}.{{ .Resource.Kind }})
+	{{- else }}
 	{{ lower .Resource.Kind }}, ok := obj.(*{{ .Resource.Kind }})
+	{{- end }}
 	if !ok {
 		return nil, fmt.Errorf("expected a {{ .Resource.Kind }} object but got %T", obj)
 	}

pkg/plugins/golang/v4/scaffolds/internal/templates/api/webhook_suitetest.go

@@ -44,6 +44,8 @@ type WebhookSuite struct { //nolint:maligned
 
 	// BaseDirectoryRelativePath define the Path for the base directory when it is multigroup
 	BaseDirectoryRelativePath string
+
+	ExternalAPI bool
 }
 
 // SetTemplateDefaults implements file.Template
@@ -101,6 +103,11 @@ const (
 	addWebhookManagerCodeFragment = `err = (&%s{}).SetupWebhookWithManager(mgr)
 Expect(err).NotTo(HaveOccurred())
 
+`
+
+	addWebhookExternalManagerCodeFragment = `err = SetupWebhookFor%sWithManager(mgr)
+Expect(err).NotTo(HaveOccurred())
+
 `
 )
 
@@ -117,7 +124,11 @@ func (f *WebhookSuite) GetCodeFragments() machinery.CodeFragmentsMap {
 
 	// Generate add webhookManager code fragments
 	addWebhookManager := make([]string, 0)
-	addWebhookManager = append(addWebhookManager, fmt.Sprintf(addWebhookManagerCodeFragment, f.Resource.Kind))
+	if f.ExternalAPI {
+		addWebhookManager = append(addWebhookManager, fmt.Sprintf(addWebhookExternalManagerCodeFragment, f.Resource.Kind))
+	} else {
+		addWebhookManager = append(addWebhookManager, fmt.Sprintf(addWebhookManagerCodeFragment, f.Resource.Kind))
+	}
 
 	// Only store code fragments in the map if the slices are non-empty
 	if len(addWebhookManager) != 0 {
@@ -159,6 +170,9 @@ import (
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
+	{{- if .ExternalAPI }}
+	{{ .Resource.ImportAlias }} "{{ .Resource.Path }}"
+	{{- end }}
 )
 
 // These tests use Ginkgo (BDD-style Go testing framework). Refer to
@@ -208,7 +222,11 @@ var _ = BeforeSuite(func() {
 	Expect(cfg).NotTo(BeNil())
 
 	scheme := apimachineryruntime.NewScheme()
+	{{- if .ExternalAPI }}
+	err = {{- .Resource.ImportAlias }}.AddToScheme(scheme)
+	{{- else }}
 	err = AddToScheme(scheme)
+	{{- end }}
 	Expect(err).NotTo(HaveOccurred())
 
 	err = %s.AddToScheme(scheme)

pkg/plugins/golang/v4/scaffolds/internal/templates/api/webhook_test_template.go

@@ -35,6 +35,8 @@ type WebhookTest struct { // nolint:maligned
 	machinery.BoilerplateMixin
 	machinery.ResourceMixin
 
+	ExternalAPI bool
+
 	Force bool
 }
 
@@ -77,17 +79,28 @@ package {{ .Resource.Version }}
 import (
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+	{{- if .ExternalAPI }}
+	{{ .Resource.ImportAlias }} "{{ .Resource.Path }}"
+	{{- end }}
 
 	// TODO (user): Add any additional imports if needed
 )
 
 var _ = Describe("{{ .Resource.Kind }} Webhook", func() {
 	var (
+		{{- if .ExternalAPI }}
+		obj *{{ .Resource.ImportAlias }}.{{ .Resource.Kind }}
+		{{- else }}
 		obj *{{ .Resource.Kind }}
+		{{- end }}
 	)
 
 	BeforeEach(func() {
+		{{- if .ExternalAPI }}
+		obj = &{{ .Resource.ImportAlias }}.{{ .Resource.Kind }}{}
+		{{- else }}
 		obj = &{{ .Resource.Kind }}{}
+		{{- end }}
 		Expect(obj).NotTo(BeNil(), "Expected obj to be initialized")
 
 		// TODO (user): Add any setup logic common to all tests
@@ -106,7 +119,11 @@ Context("When creating {{ .Resource.Kind }} under Conversion Webhook", func() {
 	// TODO (user): Add logic to convert the object to the desired version and verify the conversion
 	// Example:
 	// It("Should convert the object correctly", func() {
+	{{- if .ExternalAPI }}
+	//     convertedObj := &{{ .Resource.ImportAlias }}.{{ .Resource.Kind }}{}
+	{{- else }}
 	//     convertedObj := &{{ .Resource.Kind }}{}
+	{{- end }}
 	//     Expect(obj.ConvertTo(convertedObj)).To(Succeed())
 	//     Expect(convertedObj).ToNot(BeNil())
 	// })

pkg/plugins/golang/v4/scaffolds/internal/templates/main.go

@@ -21,6 +21,7 @@ import (
 	"path/filepath"
 
 	"sigs.k8s.io/kubebuilder/v4/pkg/machinery"
+	"sigs.k8s.io/kubebuilder/v4/pkg/model/resource"
 )
 
 const defaultMainPath = "cmd/main.go"
@@ -62,6 +63,7 @@ type MainUpdater struct { //nolint:maligned
 
 	// Flags to indicate which parts need to be included when updating the file
 	WireResource, WireController, WireWebhook bool
+	ExternalAPI                               bool
 }
 
 // GetPath implements file.Builder
@@ -122,6 +124,15 @@ const (
 		}
 	}
 `
+
+	webhookExternalSetupCodeFragment = `// nolint:goconst
+	if os.Getenv("ENABLE_WEBHOOKS") != "false" {
+		if err = %s.SetupWebhookFor%sWithManager(mgr); err != nil {
+			setupLog.Error(err, "unable to create webhook", "webhook", "%s")
+			os.Exit(1)
+		}
+	}
+`
 )
 
 // GetCodeFragments implements file.Inserter
@@ -165,10 +176,16 @@ func (f *MainUpdater) GetCodeFragments() machinery.CodeFragmentsMap {
 				f.Resource.PackageName(), f.Resource.Kind, f.Resource.Kind))
 		}
 	}
-	if f.WireWebhook {
+	if f.WireWebhook && !f.ExternalAPI {
 		setup = append(setup, fmt.Sprintf(webhookSetupCodeFragment,
 			f.Resource.ImportAlias(), f.Resource.Kind, f.Resource.Kind))
 	}
+	if f.WireWebhook && f.ExternalAPI {
+		path := resource.APIPackagePath(f.Repo, f.Resource.Group, f.Resource.Version, f.MultiGroup)
+		imports = append(imports, fmt.Sprintf(apiImportCodeFragment, f.Resource.ImportAlias(), path))
+		setup = append(setup, fmt.Sprintf(webhookExternalSetupCodeFragment,
+			f.Resource.ImportAlias(), f.Resource.Kind, f.Resource.Kind))
+	}
 
 	// Only store code fragments in the map if the slices are non-empty
 	if len(imports) != 0 {

pkg/plugins/golang/v4/scaffolds/webhook.go

@@ -18,6 +18,7 @@ package scaffolds
 
 import (
 	"fmt"
+	"strings"
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/afero"
@@ -85,11 +86,13 @@ func (s *webhookScaffolder) Scaffold() error {
 		return fmt.Errorf("error updating resource: %w", err)
 	}
 
+	externalAPI := !strings.HasPrefix(s.resource.Path, s.config.GetRepository())
+
 	if err := scaffold.Execute(
-		&api.Webhook{Force: s.force},
+		&api.Webhook{Force: s.force, ExternalAPI: externalAPI},
 		&e2e.WebhookTestUpdater{WireWebhook: true},
-		&templates.MainUpdater{WireWebhook: true},
-		&api.WebhookTest{Force: s.force},
+		&templates.MainUpdater{WireWebhook: true, ExternalAPI: externalAPI},
+		&api.WebhookTest{Force: s.force, ExternalAPI: externalAPI},
 	); err != nil {
 		return err
 	}
@@ -102,7 +105,7 @@ You need to implement the conversion.Hub and conversion.Convertible interfaces f
 	// TODO: Add test suite for conversion webhook after #1664 has been merged & conversion tests supported in envtest.
 	if doDefaulting || doValidation {
 		if err := scaffold.Execute(
-			&api.WebhookSuite{K8SVersion: EnvtestK8SVersion},
+			&api.WebhookSuite{K8SVersion: EnvtestK8SVersion, ExternalAPI: externalAPI},
 		); err != nil {
 			return err
 		}

pkg/plugins/golang/v4/webhook.go

@@ -96,12 +96,17 @@ func (p *createWebhookSubcommand) InjectResource(res *resource.Resource) error {
 			" --programmatic-validation and --conversion to be true", p.commandName)
 	}
 
-	// check if resource exist to create webhook
-	if r, err := p.config.GetResource(p.resource.GVK); err != nil {
-		return fmt.Errorf("%s create webhook requires a previously created API ", p.commandName)
-	} else if r.Webhooks != nil && !r.Webhooks.IsEmpty() && !p.force {
+	if p.force {
+		return nil
+	}
+
+	r, err := p.config.GetResource(p.resource.GVK)
+	if err == nil && r.Webhooks != nil && !r.Webhooks.IsEmpty() {
 		return fmt.Errorf("webhook resource already exists")
 	}
+	if err == nil && r.API == nil || err != nil && res.Path == "" {
+		return fmt.Errorf("%s create webhook requires a previously created API or a core API", p.commandName)
+	}
 
 	return nil
 }