✨ enable conversion webhook by default

examples/conversion/pkg/apis/jobs/v1/register.go

@@ -25,15 +25,15 @@ package v1
 
 import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
-	controllers "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/scheme"
 )
 
 var (
 	// SchemeGroupVersion is group version used to register these objects
 	SchemeGroupVersion = schema.GroupVersion{Group: "jobs.example.org", Version: "v1"}
 
 	// SchemeBuilder is used to add go types to the GroupVersionKind scheme
-	SchemeBuilder = &controllers.SchemeBuilder{GroupVersion: SchemeGroupVersion}
+	SchemeBuilder = &scheme.Builder{GroupVersion: SchemeGroupVersion}
 
 	// AddToScheme is required by pkg/client/...
 	AddToScheme = SchemeBuilder.AddToScheme

examples/conversion/pkg/apis/jobs/v2/register.go

@@ -25,15 +25,15 @@ package v2
 
 import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
-	controllers "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/scheme"
 )
 
 var (
 	// SchemeGroupVersion is group version used to register these objects
 	SchemeGroupVersion = schema.GroupVersion{Group: "jobs.example.org", Version: "v2"}
 
 	// SchemeBuilder is used to add go types to the GroupVersionKind scheme
-	SchemeBuilder = &controllers.SchemeBuilder{GroupVersion: SchemeGroupVersion}
+	SchemeBuilder = &scheme.Builder{GroupVersion: SchemeGroupVersion}
 
 	// AddToScheme is required by pkg/client/...
 	AddToScheme = SchemeBuilder.AddToScheme

go.mod

@@ -7,26 +7,23 @@ require (
 	github.com/appscode/jsonpatch v0.0.0-20190108182946-7c0e3b262f30
 	github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973 // indirect
 	github.com/evanphx/json-patch v4.1.0+incompatible
-	github.com/fsnotify/fsnotify v1.4.7 // indirect
 	github.com/ghodss/yaml v1.0.0
 	github.com/go-logr/logr v0.1.0
 	github.com/go-logr/zapr v0.1.0
-	github.com/gogo/protobuf v1.1.1 // indirect
 	github.com/golang/groupcache v0.0.0-20180513044358-24b0969c4cb7 // indirect
-	github.com/golang/protobuf v1.2.0 // indirect
+	github.com/golangci/golangci-lint v1.15.0 // indirect
 	github.com/google/btree v1.0.0 // indirect
 	github.com/google/gofuzz v0.0.0-20170612174753-24818f796faf // indirect
 	github.com/googleapis/gnostic v0.2.0 // indirect
 	github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7 // indirect
 	github.com/hashicorp/golang-lru v0.0.0-20180201235237-0fb14efe8c47 // indirect
-	github.com/hpcloud/tail v1.0.0 // indirect
 	github.com/imdario/mergo v0.3.6 // indirect
 	github.com/json-iterator/go v1.1.5 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 // indirect
 	github.com/onsi/ginkgo v1.6.0
-	github.com/onsi/gomega v1.4.1
+	github.com/onsi/gomega v1.4.2
 	github.com/pborman/uuid v0.0.0-20170612153648-e790cca94e6c // indirect
 	github.com/peterbourgon/diskv v2.0.1+incompatible // indirect
 	github.com/pkg/errors v0.8.1 // indirect
@@ -39,23 +36,17 @@ require (
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.9.1
 	golang.org/x/crypto v0.0.0-20180820150726-614d502a4dac // indirect
-	golang.org/x/net v0.0.0-20180821023952-922f4815f713 // indirect
 	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be // indirect
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
-	golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc // indirect
-	golang.org/x/text v0.3.0 // indirect
 	golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2 // indirect
 	google.golang.org/appengine v1.1.0 // indirect
-	gopkg.in/fsnotify.v1 v1.4.7 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
-	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
-	gopkg.in/yaml.v2 v2.2.1 // indirect
 	k8s.io/api v0.0.0-20190222213804-5cb15d344471
 	k8s.io/apiextensions-apiserver v0.0.0-20190228180357-d002e88f6236
 	k8s.io/apimachinery v0.0.0-20190221213512-86fb29eff628
 	k8s.io/client-go v0.0.0-20190228174230-b40b2a5939e4
 	k8s.io/klog v0.1.0 // indirect
 	k8s.io/kube-openapi v0.0.0-20180731170545-e3762e86a74c // indirect
 	sigs.k8s.io/testing_frameworks v0.1.1
-	sigs.k8s.io/yaml v1.1.0 // indirect
+	sigs.k8s.io/yaml v1.1.0
 )

pkg/builder/build.go

@@ -32,6 +32,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 	"sigs.k8s.io/controller-runtime/pkg/source"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/conversion"
 )
 
 // Supporting mocking out functions for testing
@@ -285,7 +286,15 @@ func (blder *Builder) doWebhook() error {
 		}
 	}
 
-	return err
+	err = conversion.CheckConvertibility(blder.mgr.GetScheme(), blder.apiType)
+	if err != nil {
+		log.Error(err, "conversion check failed", "GVK", gvk)
+		// TODO(droot): suppressing this error because we will get false positives
+		// for the multi-version types that are not managed by user-project.
+		// Figure out a safe approach to make it stricter.
+		return nil
+	}
+	return nil
 }
 
 func generateMutatePath(gvk schema.GroupVersionKind) string {

pkg/manager/internal.go

@@ -38,6 +38,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/recorder"
 	"sigs.k8s.io/controller-runtime/pkg/runtime/inject"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/conversion"
 )
 
 var log = logf.RuntimeLog.WithName("manager")
@@ -191,6 +192,7 @@ func (cm *controllerManager) GetWebhookServer() *webhook.Server {
 			Port: cm.port,
 			Host: cm.host,
 		}
+		cm.webhookServer.Register("/convert", &conversion.Webhook{})
 		if err := cm.Add(cm.webhookServer); err != nil {
 			panic("unable to add webhookServer to the controller manager")
 		}

pkg/webhook/conversion/conversion.go

@@ -212,6 +212,44 @@ func (wh *Webhook) allocateDstObject(apiVersion, kind string) (runtime.Object, e
 	return obj, nil
 }
 
+// CheckConvertibility determines if given type is convertible or not. For a type
+// to be convertible, the group-kind needs to have a Hub type defined and all
+// non-hub types must be able to convert to/from Hub.
+func CheckConvertibility(scheme *runtime.Scheme, obj runtime.Object) error {
+	gvks, _, err := scheme.ObjectKinds(obj)
+	if err != nil {
+		return fmt.Errorf("error retriving object kinds for given object : %v", err)
+	}
+
+	hubFound := false
+	for _, gvk := range gvks {
+		instance, err := scheme.New(gvk)
+		if err != nil {
+			return fmt.Errorf("failed to allocate an instance for gvk %v %v", gvk, err)
+		}
+
+		if isHub(instance) {
+			if hubFound {
+				return fmt.Errorf("multiple hub version defined for %T", obj)
+			}
+			hubFound = true
+			continue
+		}
+
+		if !isConvertible(instance) {
+			// non-hub needs to be convertible
+			return fmt.Errorf("%T needs to be convertible", instance)
+		}
+	}
+
+	if len(gvks) > 1 && !hubFound {
+		// multiple version discovered with no hub defined
+		return fmt.Errorf("%T has no hub defined", obj)
+	}
+
+	return nil
+}
+
 // isHub determines if passed-in object is a Hub or not.
 func isHub(obj runtime.Object) bool {
 	_, yes := obj.(conversion.Hub)

pkg/webhook/conversion/conversion_test.go

@@ -200,3 +200,39 @@ var _ = Describe("Conversion Webhook", func() {
 	})
 
 })
+
+var _ = Describe("Convertibility Check", func() {
+
+	var scheme *runtime.Scheme
+
+	BeforeEach(func() {
+
+		scheme = kscheme.Scheme
+		Expect(jobsapis.AddToScheme(scheme)).To(Succeed())
+
+	})
+
+	It("should not return error for convertible types", func() {
+		obj := &jobsv2.ExternalJob{
+			TypeMeta: metav1.TypeMeta{
+				Kind:       "ExternalJob",
+				APIVersion: "jobs.example.org/v2",
+			},
+		}
+
+		err := CheckConvertibility(scheme, obj)
+		Expect(err).NotTo(HaveOccurred())
+	})
+
+	It("should return error for non-convertible multi-version type", func() {
+		obj := &appsv1beta1.Deployment{
+			TypeMeta: metav1.TypeMeta{
+				Kind:       "Deployment",
+				APIVersion: "apps/v1beta1",
+			},
+		}
+
+		err := CheckConvertibility(scheme, obj)
+		Expect(err).To(HaveOccurred())
+	})
+})