Kubectl convert - warn users with NotRegisteredError and Fail on all other errors (#117002)

* Convert file but warn user with impossible conversions

* Only continuing for NotRegisteredErrors. Using iostreams for warning user instead of stdError

* Formatting, correct tests to use valid DNS-1035.

pkg/kubectl/cmd/convert/convert.go

@@ -180,7 +180,7 @@ func (o *ConvertOptions) RunConvert() error {
 
 	internalEncoder := scheme.Codecs.LegacyCodec(scheme.Scheme.PrioritizedVersionsAllGroups()...)
 	internalVersionJSONEncoder := unstructured.NewJSONFallbackEncoder(internalEncoder)
-	objects, err := asVersionedObject(infos, !singleItemImplied, specifiedOutputVersion, internalVersionJSONEncoder)
+	objects, err := asVersionedObject(infos, !singleItemImplied, specifiedOutputVersion, internalVersionJSONEncoder, o.IOStreams)
 	if err != nil {
 		return err
 	}
@@ -192,8 +192,8 @@ func (o *ConvertOptions) RunConvert() error {
 // the objects as children, or if only a single Object is present, as that object. The provided
 // version will be preferred as the conversion target, but the Object's mapping version will be
 // used if that version is not present.
-func asVersionedObject(infos []*resource.Info, forceList bool, specifiedOutputVersion schema.GroupVersion, encoder runtime.Encoder) (runtime.Object, error) {
-	objects, err := asVersionedObjects(infos, specifiedOutputVersion, encoder)
+func asVersionedObject(infos []*resource.Info, forceList bool, specifiedOutputVersion schema.GroupVersion, encoder runtime.Encoder, iostream genericclioptions.IOStreams) (runtime.Object, error) {
+	objects, err := asVersionedObjects(infos, specifiedOutputVersion, encoder, iostream)
 	if err != nil {
 		return nil, err
 	}
@@ -230,7 +230,7 @@ func asVersionedObject(infos []*resource.Info, forceList bool, specifiedOutputVe
 // asVersionedObjects converts a list of infos into versioned objects. The provided
 // version will be preferred as the conversion target, but the Object's mapping version will be
 // used if that version is not present.
-func asVersionedObjects(infos []*resource.Info, specifiedOutputVersion schema.GroupVersion, encoder runtime.Encoder) ([]runtime.Object, error) {
+func asVersionedObjects(infos []*resource.Info, specifiedOutputVersion schema.GroupVersion, encoder runtime.Encoder, iostream genericclioptions.IOStreams) ([]runtime.Object, error) {
 	objects := []runtime.Object{}
 	for _, info := range infos {
 		if info.Object == nil {
@@ -263,6 +263,14 @@ func asVersionedObjects(infos []*resource.Info, specifiedOutputVersion schema.Gr
 
 		converted, err := tryConvert(scheme.Scheme, info.Object, targetVersions...)
 		if err != nil {
+			// Dont fail on not registered error converting objects.
+			// Simply warn the user with the error returned from api-machinery and continue with the rest of the file
+			// fail on all other errors
+			if runtime.IsNotRegisteredError(err) {
+				fmt.Fprintln(iostream.ErrOut, err.Error())
+				continue
+			}
+
 			return nil, err
 		}
 		objects = append(objects, converted)

pkg/kubectl/cmd/convert/convert_test.go

@@ -100,6 +100,16 @@ func TestConvertObject(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:          "converting multiple including service to neworking.k8s.io/v1",
+			file:          "../../../../test/fixtures/pkg/kubectl/cmd/convert/serviceandingress.yaml",
+			outputVersion: "networking.k8s.io/v1",
+			fields: []checkField{
+				{
+					expected: "apiVersion: networking.k8s.io/v1",
+				},
+			},
+		},
 	}
 
 	for _, tc := range testcases {

test/fixtures/pkg/kubectl/cmd/convert/serviceandingress.yaml

@@ -0,0 +1,34 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: test-cluster-ip
+spec:
+  ports:
+  - name: port
+    port: 80
+    protocol: TCP
+    targetPort: 80
+  selector:
+    app: test-cluster-ip
+  type: ClusterIP
+---
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: test-ingress
+spec:
+  rules:
+  - host: test.com
+    http:
+      paths:
+      - backend:
+          serviceName: test1
+          servicePort: 80
+        path: /test1
+        pathType: ImplementationSpecific
+      - backend:
+          serviceName: webapi
+          servicePort: 80
+        path: /test2
+        pathType: ImplementationSpecific
+