git subrepo clone (merge) https://github.com/kubernetes-incubator/metrics-server.git metrics-server

subrepo:
  subdir:   "metrics-server"
  merged:   "92d8412"
upstream:
  origin:   "https://github.com/kubernetes-incubator/metrics-server.git"
  branch:   "master"
  commit:   "92d8412"
git-subrepo:
  version:  "0.4.0"
  origin:   "???"
  commit:   "???"
diff --git a/metrics-server/vendor/k8s.io/apimachinery/pkg/runtime/scheme.go b/metrics-server/vendor/k8s.io/apimachinery/pkg/runtime/scheme.go
new file mode 100644
index 0000000..59163d7
--- /dev/null
+++ b/metrics-server/vendor/k8s.io/apimachinery/pkg/runtime/scheme.go
@@ -0,0 +1,766 @@
+/*
+Copyright 2014 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package runtime
+
+import (
+	"fmt"
+	"net/url"
+	"reflect"
+
+	"strings"
+
+	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/sets"
+)
+
+// Scheme defines methods for serializing and deserializing API objects, a type
+// registry for converting group, version, and kind information to and from Go
+// schemas, and mappings between Go schemas of different versions. A scheme is the
+// foundation for a versioned API and versioned configuration over time.
+//
+// In a Scheme, a Type is a particular Go struct, a Version is a point-in-time
+// identifier for a particular representation of that Type (typically backwards
+// compatible), a Kind is the unique name for that Type within the Version, and a
+// Group identifies a set of Versions, Kinds, and Types that evolve over time. An
+// Unversioned Type is one that is not yet formally bound to a type and is promised
+// to be backwards compatible (effectively a "v1" of a Type that does not expect
+// to break in the future).
+//
+// Schemes are not expected to change at runtime and are only threadsafe after
+// registration is complete.
+type Scheme struct {
+	// versionMap allows one to figure out the go type of an object with
+	// the given version and name.
+	gvkToType map[schema.GroupVersionKind]reflect.Type
+
+	// typeToGroupVersion allows one to find metadata for a given go object.
+	// The reflect.Type we index by should *not* be a pointer.
+	typeToGVK map[reflect.Type][]schema.GroupVersionKind
+
+	// unversionedTypes are transformed without conversion in ConvertToVersion.
+	unversionedTypes map[reflect.Type]schema.GroupVersionKind
+
+	// unversionedKinds are the names of kinds that can be created in the context of any group
+	// or version
+	// TODO: resolve the status of unversioned types.
+	unversionedKinds map[string]reflect.Type
+
+	// Map from version and resource to the corresponding func to convert
+	// resource field labels in that version to internal version.
+	fieldLabelConversionFuncs map[string]map[string]FieldLabelConversionFunc
+
+	// defaulterFuncs is an array of interfaces to be called with an object to provide defaulting
+	// the provided object must be a pointer.
+	defaulterFuncs map[reflect.Type]func(interface{})
+
+	// converter stores all registered conversion functions. It also has
+	// default coverting behavior.
+	converter *conversion.Converter
+
+	// versionPriority is a map of groups to ordered lists of versions for those groups indicating the
+	// default priorities of these versions as registered in the scheme
+	versionPriority map[string][]string
+
+	// observedVersions keeps track of the order we've seen versions during type registration
+	observedVersions []schema.GroupVersion
+}
+
+// Function to convert a field selector to internal representation.
+type FieldLabelConversionFunc func(label, value string) (internalLabel, internalValue string, err error)
+
+// NewScheme creates a new Scheme. This scheme is pluggable by default.
+func NewScheme() *Scheme {
+	s := &Scheme{
+		gvkToType:                 map[schema.GroupVersionKind]reflect.Type{},
+		typeToGVK:                 map[reflect.Type][]schema.GroupVersionKind{},
+		unversionedTypes:          map[reflect.Type]schema.GroupVersionKind{},
+		unversionedKinds:          map[string]reflect.Type{},
+		fieldLabelConversionFuncs: map[string]map[string]FieldLabelConversionFunc{},
+		defaulterFuncs:            map[reflect.Type]func(interface{}){},
+		versionPriority:           map[string][]string{},
+	}
+	s.converter = conversion.NewConverter(s.nameFunc)
+
+	s.AddConversionFuncs(DefaultEmbeddedConversions()...)
+
+	// Enable map[string][]string conversions by default
+	if err := s.AddConversionFuncs(DefaultStringConversions...); err != nil {
+		panic(err)
+	}
+	if err := s.RegisterInputDefaults(&map[string][]string{}, JSONKeyMapper, conversion.AllowDifferentFieldTypeNames|conversion.IgnoreMissingFields); err != nil {
+		panic(err)
+	}
+	if err := s.RegisterInputDefaults(&url.Values{}, JSONKeyMapper, conversion.AllowDifferentFieldTypeNames|conversion.IgnoreMissingFields); err != nil {
+		panic(err)
+	}
+	return s
+}
+
+// nameFunc returns the name of the type that we wish to use to determine when two types attempt
+// a conversion. Defaults to the go name of the type if the type is not registered.
+func (s *Scheme) nameFunc(t reflect.Type) string {
+	// find the preferred names for this type
+	gvks, ok := s.typeToGVK[t]
+	if !ok {
+		return t.Name()
+	}
+
+	for _, gvk := range gvks {
+		internalGV := gvk.GroupVersion()
+		internalGV.Version = APIVersionInternal // this is hacky and maybe should be passed in
+		internalGVK := internalGV.WithKind(gvk.Kind)
+
+		if internalType, exists := s.gvkToType[internalGVK]; exists {
+			return s.typeToGVK[internalType][0].Kind
+		}
+	}
+
+	return gvks[0].Kind
+}
+
+// fromScope gets the input version, desired output version, and desired Scheme
+// from a conversion.Scope.
+func (s *Scheme) fromScope(scope conversion.Scope) *Scheme {
+	return s
+}
+
+// Converter allows access to the converter for the scheme
+func (s *Scheme) Converter() *conversion.Converter {
+	return s.converter
+}
+
+// AddUnversionedTypes registers the provided types as "unversioned", which means that they follow special rules.
+// Whenever an object of this type is serialized, it is serialized with the provided group version and is not
+// converted. Thus unversioned objects are expected to remain backwards compatible forever, as if they were in an
+// API group and version that would never be updated.
+//
+// TODO: there is discussion about removing unversioned and replacing it with objects that are manifest into
+//   every version with particular schemas. Resolve this method at that point.
+func (s *Scheme) AddUnversionedTypes(version schema.GroupVersion, types ...Object) {
+	s.addObservedVersion(version)
+	s.AddKnownTypes(version, types...)
+	for _, obj := range types {
+		t := reflect.TypeOf(obj).Elem()
+		gvk := version.WithKind(t.Name())
+		s.unversionedTypes[t] = gvk
+		if old, ok := s.unversionedKinds[gvk.Kind]; ok && t != old {
+			panic(fmt.Sprintf("%v.%v has already been registered as unversioned kind %q - kind name must be unique", old.PkgPath(), old.Name(), gvk))
+		}
+		s.unversionedKinds[gvk.Kind] = t
+	}
+}
+
+// AddKnownTypes registers all types passed in 'types' as being members of version 'version'.
+// All objects passed to types should be pointers to structs. The name that go reports for
+// the struct becomes the "kind" field when encoding. Version may not be empty - use the
+// APIVersionInternal constant if you have a type that does not have a formal version.
+func (s *Scheme) AddKnownTypes(gv schema.GroupVersion, types ...Object) {
+	s.addObservedVersion(gv)
+	for _, obj := range types {
+		t := reflect.TypeOf(obj)
+		if t.Kind() != reflect.Ptr {
+			panic("All types must be pointers to structs.")
+		}
+		t = t.Elem()
+		s.AddKnownTypeWithName(gv.WithKind(t.Name()), obj)
+	}
+}
+
+// AddKnownTypeWithName is like AddKnownTypes, but it lets you specify what this type should
+// be encoded as. Useful for testing when you don't want to make multiple packages to define
+// your structs. Version may not be empty - use the APIVersionInternal constant if you have a
+// type that does not have a formal version.
+func (s *Scheme) AddKnownTypeWithName(gvk schema.GroupVersionKind, obj Object) {
+	s.addObservedVersion(gvk.GroupVersion())
+	t := reflect.TypeOf(obj)
+	if len(gvk.Version) == 0 {
+		panic(fmt.Sprintf("version is required on all types: %s %v", gvk, t))
+	}
+	if t.Kind() != reflect.Ptr {
+		panic("All types must be pointers to structs.")
+	}
+	t = t.Elem()
+	if t.Kind() != reflect.Struct {
+		panic("All types must be pointers to structs.")
+	}
+
+	if oldT, found := s.gvkToType[gvk]; found && oldT != t {
+		panic(fmt.Sprintf("Double registration of different types for %v: old=%v.%v, new=%v.%v", gvk, oldT.PkgPath(), oldT.Name(), t.PkgPath(), t.Name()))
+	}
+
+	s.gvkToType[gvk] = t
+
+	for _, existingGvk := range s.typeToGVK[t] {
+		if existingGvk == gvk {
+			return
+		}
+	}
+	s.typeToGVK[t] = append(s.typeToGVK[t], gvk)
+}
+
+// KnownTypes returns the types known for the given version.
+func (s *Scheme) KnownTypes(gv schema.GroupVersion) map[string]reflect.Type {
+	types := make(map[string]reflect.Type)
+	for gvk, t := range s.gvkToType {
+		if gv != gvk.GroupVersion() {
+			continue
+		}
+
+		types[gvk.Kind] = t
+	}
+	return types
+}
+
+// AllKnownTypes returns the all known types.
+func (s *Scheme) AllKnownTypes() map[schema.GroupVersionKind]reflect.Type {
+	return s.gvkToType
+}
+
+// ObjectKinds returns all possible group,version,kind of the go object, true if the
+// object is considered unversioned, or an error if it's not a pointer or is unregistered.
+func (s *Scheme) ObjectKinds(obj Object) ([]schema.GroupVersionKind, bool, error) {
+	// Unstructured objects are always considered to have their declared GVK
+	if _, ok := obj.(Unstructured); ok {
+		// we require that the GVK be populated in order to recognize the object
+		gvk := obj.GetObjectKind().GroupVersionKind()
+		if len(gvk.Kind) == 0 {
+			return nil, false, NewMissingKindErr("unstructured object has no kind")
+		}
+		if len(gvk.Version) == 0 {
+			return nil, false, NewMissingVersionErr("unstructured object has no version")
+		}
+		return []schema.GroupVersionKind{gvk}, false, nil
+	}
+
+	v, err := conversion.EnforcePtr(obj)
+	if err != nil {
+		return nil, false, err
+	}
+	t := v.Type()
+
+	gvks, ok := s.typeToGVK[t]
+	if !ok {
+		return nil, false, NewNotRegisteredErrForType(t)
+	}
+	_, unversionedType := s.unversionedTypes[t]
+
+	return gvks, unversionedType, nil
+}
+
+// Recognizes returns true if the scheme is able to handle the provided group,version,kind
+// of an object.
+func (s *Scheme) Recognizes(gvk schema.GroupVersionKind) bool {
+	_, exists := s.gvkToType[gvk]
+	return exists
+}
+
+func (s *Scheme) IsUnversioned(obj Object) (bool, bool) {
+	v, err := conversion.EnforcePtr(obj)
+	if err != nil {
+		return false, false
+	}
+	t := v.Type()
+
+	if _, ok := s.typeToGVK[t]; !ok {
+		return false, false
+	}
+	_, ok := s.unversionedTypes[t]
+	return ok, true
+}
+
+// New returns a new API object of the given version and name, or an error if it hasn't
+// been registered. The version and kind fields must be specified.
+func (s *Scheme) New(kind schema.GroupVersionKind) (Object, error) {
+	if t, exists := s.gvkToType[kind]; exists {
+		return reflect.New(t).Interface().(Object), nil
+	}
+
+	if t, exists := s.unversionedKinds[kind.Kind]; exists {
+		return reflect.New(t).Interface().(Object), nil
+	}
+	return nil, NewNotRegisteredErrForKind(kind)
+}
+
+// AddGenericConversionFunc adds a function that accepts the ConversionFunc call pattern
+// (for two conversion types) to the converter. These functions are checked first during
+// a normal conversion, but are otherwise not called. Use AddConversionFuncs when registering
+// typed conversions.
+func (s *Scheme) AddGenericConversionFunc(fn conversion.GenericConversionFunc) {
+	s.converter.AddGenericConversionFunc(fn)
+}
+
+// Log sets a logger on the scheme. For test purposes only
+func (s *Scheme) Log(l conversion.DebugLogger) {
+	s.converter.Debug = l
+}
+
+// AddIgnoredConversionType identifies a pair of types that should be skipped by
+// conversion (because the data inside them is explicitly dropped during
+// conversion).
+func (s *Scheme) AddIgnoredConversionType(from, to interface{}) error {
+	return s.converter.RegisterIgnoredConversion(from, to)
+}
+
+// AddConversionFuncs adds functions to the list of conversion functions. The given
+// functions should know how to convert between two of your API objects, or their
+// sub-objects. We deduce how to call these functions from the types of their two
+// parameters; see the comment for Converter.Register.
+//
+// Note that, if you need to copy sub-objects that didn't change, you can use the
+// conversion.Scope object that will be passed to your conversion function.
+// Additionally, all conversions started by Scheme will set the SrcVersion and
+// DestVersion fields on the Meta object. Example:
+//
+// s.AddConversionFuncs(
+//	func(in *InternalObject, out *ExternalObject, scope conversion.Scope) error {
+//		// You can depend on Meta() being non-nil, and this being set to
+//		// the source version, e.g., ""
+//		s.Meta().SrcVersion
+//		// You can depend on this being set to the destination version,
+//		// e.g., "v1".
+//		s.Meta().DestVersion
+//		// Call scope.Convert to copy sub-fields.
+//		s.Convert(&in.SubFieldThatMoved, &out.NewLocation.NewName, 0)
+//		return nil
+//	},
+// )
+//
+// (For more detail about conversion functions, see Converter.Register's comment.)
+//
+// Also note that the default behavior, if you don't add a conversion function, is to
+// sanely copy fields that have the same names and same type names. It's OK if the
+// destination type has extra fields, but it must not remove any. So you only need to
+// add conversion functions for things with changed/removed fields.
+func (s *Scheme) AddConversionFuncs(conversionFuncs ...interface{}) error {
+	for _, f := range conversionFuncs {
+		if err := s.converter.RegisterConversionFunc(f); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AddGeneratedConversionFuncs registers conversion functions that were
+// automatically generated.
+func (s *Scheme) AddGeneratedConversionFuncs(conversionFuncs ...interface{}) error {
+	for _, f := range conversionFuncs {
+		if err := s.converter.RegisterGeneratedConversionFunc(f); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// AddFieldLabelConversionFunc adds a conversion function to convert field selectors
+// of the given kind from the given version to internal version representation.
+func (s *Scheme) AddFieldLabelConversionFunc(version, kind string, conversionFunc FieldLabelConversionFunc) error {
+	if s.fieldLabelConversionFuncs[version] == nil {
+		s.fieldLabelConversionFuncs[version] = map[string]FieldLabelConversionFunc{}
+	}
+
+	s.fieldLabelConversionFuncs[version][kind] = conversionFunc
+	return nil
+}
+
+// AddStructFieldConversion allows you to specify a mechanical copy for a moved
+// or renamed struct field without writing an entire conversion function. See
+// the comment in conversion.Converter.SetStructFieldCopy for parameter details.
+// Call as many times as needed, even on the same fields.
+func (s *Scheme) AddStructFieldConversion(srcFieldType interface{}, srcFieldName string, destFieldType interface{}, destFieldName string) error {
+	return s.converter.SetStructFieldCopy(srcFieldType, srcFieldName, destFieldType, destFieldName)
+}
+
+// RegisterInputDefaults sets the provided field mapping function and field matching
+// as the defaults for the provided input type.  The fn may be nil, in which case no
+// mapping will happen by default. Use this method to register a mechanism for handling
+// a specific input type in conversion, such as a map[string]string to structs.
+func (s *Scheme) RegisterInputDefaults(in interface{}, fn conversion.FieldMappingFunc, defaultFlags conversion.FieldMatchingFlags) error {
+	return s.converter.RegisterInputDefaults(in, fn, defaultFlags)
+}
+
+// AddTypeDefaultingFuncs registers a function that is passed a pointer to an
+// object and can default fields on the object. These functions will be invoked
+// when Default() is called. The function will never be called unless the
+// defaulted object matches srcType. If this function is invoked twice with the
+// same srcType, the fn passed to the later call will be used instead.
+func (s *Scheme) AddTypeDefaultingFunc(srcType Object, fn func(interface{})) {
+	s.defaulterFuncs[reflect.TypeOf(srcType)] = fn
+}
+
+// Default sets defaults on the provided Object.
+func (s *Scheme) Default(src Object) {
+	if fn, ok := s.defaulterFuncs[reflect.TypeOf(src)]; ok {
+		fn(src)
+	}
+}
+
+// Convert will attempt to convert in into out. Both must be pointers. For easy
+// testing of conversion functions. Returns an error if the conversion isn't
+// possible. You can call this with types that haven't been registered (for example,
+// a to test conversion of types that are nested within registered types). The
+// context interface is passed to the convertor. Convert also supports Unstructured
+// types and will convert them intelligently.
+func (s *Scheme) Convert(in, out interface{}, context interface{}) error {
+	unstructuredIn, okIn := in.(Unstructured)
+	unstructuredOut, okOut := out.(Unstructured)
+	switch {
+	case okIn && okOut:
+		// converting unstructured input to an unstructured output is a straight copy - unstructured
+		// is a "smart holder" and the contents are passed by reference between the two objects
+		unstructuredOut.SetUnstructuredContent(unstructuredIn.UnstructuredContent())
+		return nil
+
+	case okOut:
+		// if the output is an unstructured object, use the standard Go type to unstructured
+		// conversion. The object must not be internal.
+		obj, ok := in.(Object)
+		if !ok {
+			return fmt.Errorf("unable to convert object type %T to Unstructured, must be a runtime.Object", in)
+		}
+		gvks, unversioned, err := s.ObjectKinds(obj)
+		if err != nil {
+			return err
+		}
+		gvk := gvks[0]
+
+		// if no conversion is necessary, convert immediately
+		if unversioned || gvk.Version != APIVersionInternal {
+			content, err := DefaultUnstructuredConverter.ToUnstructured(in)
+			if err != nil {
+				return err
+			}
+			unstructuredOut.SetUnstructuredContent(content)
+			unstructuredOut.GetObjectKind().SetGroupVersionKind(gvk)
+			return nil
+		}
+
+		// attempt to convert the object to an external version first.
+		target, ok := context.(GroupVersioner)
+		if !ok {
+			return fmt.Errorf("unable to convert the internal object type %T to Unstructured without providing a preferred version to convert to", in)
+		}
+		// Convert is implicitly unsafe, so we don't need to perform a safe conversion
+		versioned, err := s.UnsafeConvertToVersion(obj, target)
+		if err != nil {
+			return err
+		}
+		content, err := DefaultUnstructuredConverter.ToUnstructured(versioned)
+		if err != nil {
+			return err
+		}
+		unstructuredOut.SetUnstructuredContent(content)
+		return nil
+
+	case okIn:
+		// converting an unstructured object to any type is modeled by first converting
+		// the input to a versioned type, then running standard conversions
+		typed, err := s.unstructuredToTyped(unstructuredIn)
+		if err != nil {
+			return err
+		}
+		in = typed
+	}
+
+	flags, meta := s.generateConvertMeta(in)
+	meta.Context = context
+	if flags == 0 {
+		flags = conversion.AllowDifferentFieldTypeNames
+	}
+	return s.converter.Convert(in, out, flags, meta)
+}
+
+// ConvertFieldLabel alters the given field label and value for an kind field selector from
+// versioned representation to an unversioned one or returns an error.
+func (s *Scheme) ConvertFieldLabel(version, kind, label, value string) (string, string, error) {
+	if s.fieldLabelConversionFuncs[version] == nil {
+		return DefaultMetaV1FieldSelectorConversion(label, value)
+	}
+	conversionFunc, ok := s.fieldLabelConversionFuncs[version][kind]
+	if !ok {
+		return DefaultMetaV1FieldSelectorConversion(label, value)
+	}
+	return conversionFunc(label, value)
+}
+
+// ConvertToVersion attempts to convert an input object to its matching Kind in another
+// version within this scheme. Will return an error if the provided version does not
+// contain the inKind (or a mapping by name defined with AddKnownTypeWithName). Will also
+// return an error if the conversion does not result in a valid Object being
+// returned. Passes target down to the conversion methods as the Context on the scope.
+func (s *Scheme) ConvertToVersion(in Object, target GroupVersioner) (Object, error) {
+	return s.convertToVersion(true, in, target)
+}
+
+// UnsafeConvertToVersion will convert in to the provided target if such a conversion is possible,
+// but does not guarantee the output object does not share fields with the input object. It attempts to be as
+// efficient as possible when doing conversion.
+func (s *Scheme) UnsafeConvertToVersion(in Object, target GroupVersioner) (Object, error) {
+	return s.convertToVersion(false, in, target)
+}
+
+// convertToVersion handles conversion with an optional copy.
+func (s *Scheme) convertToVersion(copy bool, in Object, target GroupVersioner) (Object, error) {
+	var t reflect.Type
+
+	if u, ok := in.(Unstructured); ok {
+		typed, err := s.unstructuredToTyped(u)
+		if err != nil {
+			return nil, err
+		}
+
+		in = typed
+		// unstructuredToTyped returns an Object, which must be a pointer to a struct.
+		t = reflect.TypeOf(in).Elem()
+
+	} else {
+		// determine the incoming kinds with as few allocations as possible.
+		t = reflect.TypeOf(in)
+		if t.Kind() != reflect.Ptr {
+			return nil, fmt.Errorf("only pointer types may be converted: %v", t)
+		}
+		t = t.Elem()
+		if t.Kind() != reflect.Struct {
+			return nil, fmt.Errorf("only pointers to struct types may be converted: %v", t)
+		}
+	}
+
+	kinds, ok := s.typeToGVK[t]
+	if !ok || len(kinds) == 0 {
+		return nil, NewNotRegisteredErrForType(t)
+	}
+
+	gvk, ok := target.KindForGroupVersionKinds(kinds)
+	if !ok {
+		// try to see if this type is listed as unversioned (for legacy support)
+		// TODO: when we move to server API versions, we should completely remove the unversioned concept
+		if unversionedKind, ok := s.unversionedTypes[t]; ok {
+			if gvk, ok := target.KindForGroupVersionKinds([]schema.GroupVersionKind{unversionedKind}); ok {
+				return copyAndSetTargetKind(copy, in, gvk)
+			}
+			return copyAndSetTargetKind(copy, in, unversionedKind)
+		}
+		return nil, NewNotRegisteredErrForTarget(t, target)
+	}
+
+	// target wants to use the existing type, set kind and return (no conversion necessary)
+	for _, kind := range kinds {
+		if gvk == kind {
+			return copyAndSetTargetKind(copy, in, gvk)
+		}
+	}
+
+	// type is unversioned, no conversion necessary
+	if unversionedKind, ok := s.unversionedTypes[t]; ok {
+		if gvk, ok := target.KindForGroupVersionKinds([]schema.GroupVersionKind{unversionedKind}); ok {
+			return copyAndSetTargetKind(copy, in, gvk)
+		}
+		return copyAndSetTargetKind(copy, in, unversionedKind)
+	}
+
+	out, err := s.New(gvk)
+	if err != nil {
+		return nil, err
+	}
+
+	if copy {
+		in = in.DeepCopyObject()
+	}
+
+	flags, meta := s.generateConvertMeta(in)
+	meta.Context = target
+	if err := s.converter.Convert(in, out, flags, meta); err != nil {
+		return nil, err
+	}
+
+	setTargetKind(out, gvk)
+	return out, nil
+}
+
+// unstructuredToTyped attempts to transform an unstructured object to a typed
+// object if possible. It will return an error if conversion is not possible, or the versioned
+// Go form of the object. Note that this conversion will lose fields.
+func (s *Scheme) unstructuredToTyped(in Unstructured) (Object, error) {
+	// the type must be something we recognize
+	gvks, _, err := s.ObjectKinds(in)
+	if err != nil {
+		return nil, err
+	}
+	typed, err := s.New(gvks[0])
+	if err != nil {
+		return nil, err
+	}
+	if err := DefaultUnstructuredConverter.FromUnstructured(in.UnstructuredContent(), typed); err != nil {
+		return nil, fmt.Errorf("unable to convert unstructured object to %v: %v", gvks[0], err)
+	}
+	return typed, nil
+}
+
+// generateConvertMeta constructs the meta value we pass to Convert.
+func (s *Scheme) generateConvertMeta(in interface{}) (conversion.FieldMatchingFlags, *conversion.Meta) {
+	return s.converter.DefaultMeta(reflect.TypeOf(in))
+}
+
+// copyAndSetTargetKind performs a conditional copy before returning the object, or an error if copy was not successful.
+func copyAndSetTargetKind(copy bool, obj Object, kind schema.GroupVersionKind) (Object, error) {
+	if copy {
+		obj = obj.DeepCopyObject()
+	}
+	setTargetKind(obj, kind)
+	return obj, nil
+}
+
+// setTargetKind sets the kind on an object, taking into account whether the target kind is the internal version.
+func setTargetKind(obj Object, kind schema.GroupVersionKind) {
+	if kind.Version == APIVersionInternal {
+		// internal is a special case
+		// TODO: look at removing the need to special case this
+		obj.GetObjectKind().SetGroupVersionKind(schema.GroupVersionKind{})
+		return
+	}
+	obj.GetObjectKind().SetGroupVersionKind(kind)
+}
+
+// SetVersionPriority allows specifying a precise order of priority. All specified versions must be in the same group,
+// and the specified order overwrites any previously specified order for this group
+func (s *Scheme) SetVersionPriority(versions ...schema.GroupVersion) error {
+	groups := sets.String{}
+	order := []string{}
+	for _, version := range versions {
+		if len(version.Version) == 0 || version.Version == APIVersionInternal {
+			return fmt.Errorf("internal versions cannot be prioritized: %v", version)
+		}
+
+		groups.Insert(version.Group)
+		order = append(order, version.Version)
+	}
+	if len(groups) != 1 {
+		return fmt.Errorf("must register versions for exactly one group: %v", strings.Join(groups.List(), ", "))
+	}
+
+	s.versionPriority[groups.List()[0]] = order
+	return nil
+}
+
+// PrioritizedVersionsForGroup returns versions for a single group in priority order
+func (s *Scheme) PrioritizedVersionsForGroup(group string) []schema.GroupVersion {
+	ret := []schema.GroupVersion{}
+	for _, version := range s.versionPriority[group] {
+		ret = append(ret, schema.GroupVersion{Group: group, Version: version})
+	}
+	for _, observedVersion := range s.observedVersions {
+		if observedVersion.Group != group {
+			continue
+		}
+		found := false
+		for _, existing := range ret {
+			if existing == observedVersion {
+				found = true
+				break
+			}
+		}
+		if !found {
+			ret = append(ret, observedVersion)
+		}
+	}
+
+	return ret
+}
+
+// PrioritizedVersionsAllGroups returns all known versions in their priority order.  Groups are random, but
+// versions for a single group are prioritized
+func (s *Scheme) PrioritizedVersionsAllGroups() []schema.GroupVersion {
+	ret := []schema.GroupVersion{}
+	for group, versions := range s.versionPriority {
+		for _, version := range versions {
+			ret = append(ret, schema.GroupVersion{Group: group, Version: version})
+		}
+	}
+	for _, observedVersion := range s.observedVersions {
+		found := false
+		for _, existing := range ret {
+			if existing == observedVersion {
+				found = true
+				break
+			}
+		}
+		if !found {
+			ret = append(ret, observedVersion)
+		}
+	}
+	return ret
+}
+
+// PreferredVersionAllGroups returns the most preferred version for every group.
+// group ordering is random.
+func (s *Scheme) PreferredVersionAllGroups() []schema.GroupVersion {
+	ret := []schema.GroupVersion{}
+	for group, versions := range s.versionPriority {
+		for _, version := range versions {
+			ret = append(ret, schema.GroupVersion{Group: group, Version: version})
+			break
+		}
+	}
+	for _, observedVersion := range s.observedVersions {
+		found := false
+		for _, existing := range ret {
+			if existing.Group == observedVersion.Group {
+				found = true
+				break
+			}
+		}
+		if !found {
+			ret = append(ret, observedVersion)
+		}
+	}
+
+	return ret
+}
+
+// IsGroupRegistered returns true if types for the group have been registered with the scheme
+func (s *Scheme) IsGroupRegistered(group string) bool {
+	for _, observedVersion := range s.observedVersions {
+		if observedVersion.Group == group {
+			return true
+		}
+	}
+	return false
+}
+
+// IsVersionRegistered returns true if types for the version have been registered with the scheme
+func (s *Scheme) IsVersionRegistered(version schema.GroupVersion) bool {
+	for _, observedVersion := range s.observedVersions {
+		if observedVersion == version {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (s *Scheme) addObservedVersion(version schema.GroupVersion) {
+	if len(version.Version) == 0 || version.Version == APIVersionInternal {
+		return
+	}
+	for _, observedVersion := range s.observedVersions {
+		if observedVersion == version {
+			return
+		}
+	}
+
+	s.observedVersions = append(s.observedVersions, version)
+}