kubectl attach support for multiple types

hot fix

add unit test and statefulSet

update example

remove package

change to ResourceNames

remove some code

remove strings

add fake testing func for AttachablePodForObject

minor change

add test.obj nil check

update testfile

gofmt

update

add fallthough

revert back

pkg/kubectl/cmd/testing/fake.go

@@ -591,6 +591,19 @@ func (f *fakeAPIFactory) LogsForObject(object, options runtime.Object) (*restcli
 	}
 }
 
+func (f *fakeAPIFactory) AttachablePodForObject(object runtime.Object) (*api.Pod, error) {
+	switch t := object.(type) {
+	case *api.Pod:
+		return t, nil
+	default:
+		gvks, _, err := api.Scheme.ObjectKinds(object)
+		if err != nil {
+			return nil, err
+		}
+		return nil, fmt.Errorf("cannot attach to %v: not implemented", gvks[0])
+	}
+}
+
 func (f *fakeAPIFactory) Validator(validate bool, cacheDir string) (validation.Schema, error) {
 	return f.tf.Validator, f.tf.Err
 }