Merge pull request #40624 from smarterclayton/storage_options

pkg/genericapiserver/server/storage_factory.go

@@ -74,7 +74,19 @@ type DefaultStorageFactory struct {
 	APIResourceConfigSource APIResourceConfigSource
 
 	// newStorageCodecFn exists to be overwritten for unit testing.
-	newStorageCodecFn func(storageMediaType string, ns runtime.StorageSerializer, storageVersion, memoryVersion schema.GroupVersion, config storagebackend.Config) (codec runtime.Codec, err error)
+	newStorageCodecFn func(opts StorageCodecConfig) (codec runtime.Codec, err error)
+}
+
+// StorageCodecConfig are the arguments passed to newStorageCodecFn
+type StorageCodecConfig struct {
+	StorageMediaType  string
+	StorageSerializer runtime.StorageSerializer
+	StorageVersion    schema.GroupVersion
+	MemoryVersion     schema.GroupVersion
+	Config            storagebackend.Config
+
+	EncoderDecoratorFn func(runtime.Encoder) runtime.Encoder
+	DecoderDecoratorFn func([]runtime.Decoder) []runtime.Decoder
 }
 
 type groupResourceOverrides struct {
@@ -95,6 +107,34 @@ type groupResourceOverrides struct {
 	// of exposing one set of concepts.  autoscaling.HPA and extensions.HPA as a for instance
 	// The order of the slice matters!  It is the priority order of lookup for finding a storage location
 	cohabitatingResources []schema.GroupResource
+	// encoderDecoratorFn is optional and may wrap the provided encoder prior to being serialized.
+	encoderDecoratorFn func(runtime.Encoder) runtime.Encoder
+	// decoderDecoratorFn is optional and may wrap the provided decoders (can add new decoders). The order of
+	// returned decoders will be priority for attempt to decode.
+	decoderDecoratorFn func([]runtime.Decoder) []runtime.Decoder
+}
+
+// Apply overrides the provided config and options if the override has a value in that position
+func (o groupResourceOverrides) Apply(config *storagebackend.Config, options *StorageCodecConfig) {
+	if len(o.etcdLocation) > 0 {
+		config.ServerList = o.etcdLocation
+	}
+	if len(o.etcdPrefix) > 0 {
+		config.Prefix = o.etcdPrefix
+	}
+
+	if len(o.mediaType) > 0 {
+		options.StorageMediaType = o.mediaType
+	}
+	if o.serializer != nil {
+		options.StorageSerializer = o.serializer
+	}
+	if o.encoderDecoratorFn != nil {
+		options.EncoderDecoratorFn = o.encoderDecoratorFn
+	}
+	if o.decoderDecoratorFn != nil {
+		options.DecoderDecoratorFn = o.decoderDecoratorFn
+	}
 }
 
 var _ StorageFactory = &DefaultStorageFactory{}
@@ -165,6 +205,15 @@ func (s *DefaultStorageFactory) AddCohabitatingResources(groupResources ...schem
 	}
 }
 
+func (s *DefaultStorageFactory) AddSerializationChains(encoderDecoratorFn func(runtime.Encoder) runtime.Encoder, decoderDecoratorFn func([]runtime.Decoder) []runtime.Decoder, groupResources ...schema.GroupResource) {
+	for _, groupResource := range groupResources {
+		overrides := s.Overrides[groupResource]
+		overrides.encoderDecoratorFn = encoderDecoratorFn
+		overrides.decoderDecoratorFn = decoderDecoratorFn
+		s.Overrides[groupResource] = overrides
+	}
+}
+
 func getAllResourcesAlias(resource schema.GroupResource) schema.GroupResource {
 	return schema.GroupResource{Group: resource.Group, Resource: AllResources}
 }
@@ -184,64 +233,38 @@ func (s *DefaultStorageFactory) getStorageGroupResource(groupResource schema.Gro
 func (s *DefaultStorageFactory) NewConfig(groupResource schema.GroupResource) (*storagebackend.Config, error) {
 	chosenStorageResource := s.getStorageGroupResource(groupResource)
 
-	groupOverride := s.Overrides[getAllResourcesAlias(chosenStorageResource)]
-	exactResourceOverride := s.Overrides[chosenStorageResource]
-
-	overriddenEtcdLocations := []string{}
-	if len(groupOverride.etcdLocation) > 0 {
-		overriddenEtcdLocations = groupOverride.etcdLocation
-	}
-	if len(exactResourceOverride.etcdLocation) > 0 {
-		overriddenEtcdLocations = exactResourceOverride.etcdLocation
-	}
-
-	etcdPrefix := s.StorageConfig.Prefix
-	if len(groupOverride.etcdPrefix) > 0 {
-		etcdPrefix = groupOverride.etcdPrefix
-	}
-	if len(exactResourceOverride.etcdPrefix) > 0 {
-		etcdPrefix = exactResourceOverride.etcdPrefix
-	}
-
-	etcdMediaType := s.DefaultMediaType
-	if len(groupOverride.mediaType) != 0 {
-		etcdMediaType = groupOverride.mediaType
-	}
-	if len(exactResourceOverride.mediaType) != 0 {
-		etcdMediaType = exactResourceOverride.mediaType
+	// operate on copy
+	storageConfig := s.StorageConfig
+	codecConfig := StorageCodecConfig{
+		StorageMediaType:  s.DefaultMediaType,
+		StorageSerializer: s.DefaultSerializer,
 	}
 
-	etcdSerializer := s.DefaultSerializer
-	if groupOverride.serializer != nil {
-		etcdSerializer = groupOverride.serializer
+	if override, ok := s.Overrides[getAllResourcesAlias(chosenStorageResource)]; ok {
+		override.Apply(&storageConfig, &codecConfig)
 	}
-	if exactResourceOverride.serializer != nil {
-		etcdSerializer = exactResourceOverride.serializer
-	}
-	// operate on copy
-	config := s.StorageConfig
-	config.Prefix = etcdPrefix
-	if len(overriddenEtcdLocations) > 0 {
-		config.ServerList = overriddenEtcdLocations
+	if override, ok := s.Overrides[chosenStorageResource]; ok {
+		override.Apply(&storageConfig, &codecConfig)
 	}
 
-	storageEncodingVersion, err := s.ResourceEncodingConfig.StorageEncodingFor(chosenStorageResource)
+	var err error
+	codecConfig.StorageVersion, err = s.ResourceEncodingConfig.StorageEncodingFor(chosenStorageResource)
 	if err != nil {
 		return nil, err
 	}
-	internalVersion, err := s.ResourceEncodingConfig.InMemoryEncodingFor(groupResource)
+	codecConfig.MemoryVersion, err = s.ResourceEncodingConfig.InMemoryEncodingFor(groupResource)
 	if err != nil {
 		return nil, err
 	}
+	codecConfig.Config = storageConfig
 
-	codec, err := s.newStorageCodecFn(etcdMediaType, etcdSerializer, storageEncodingVersion, internalVersion, config)
+	storageConfig.Codec, err = s.newStorageCodecFn(codecConfig)
 	if err != nil {
 		return nil, err
 	}
+	glog.V(3).Infof("storing %v in %v, reading as %v from %v", groupResource, codecConfig.StorageVersion, codecConfig.MemoryVersion, codecConfig.Config)
 
-	glog.V(3).Infof("storing %v in %v, reading as %v from %v", groupResource, storageEncodingVersion, internalVersion, config)
-	config.Codec = codec
-	return &config, nil
+	return &storageConfig, nil
 }
 
 // Get all backends for all registered storage destinations.
@@ -257,41 +280,51 @@ func (s *DefaultStorageFactory) Backends() []string {
 
 // NewStorageCodec assembles a storage codec for the provided storage media type, the provided serializer, and the requested
 // storage and memory versions.
-func NewStorageCodec(storageMediaType string, ns runtime.StorageSerializer, storageVersion, memoryVersion schema.GroupVersion, config storagebackend.Config) (runtime.Codec, error) {
-	mediaType, _, err := mime.ParseMediaType(storageMediaType)
+func NewStorageCodec(opts StorageCodecConfig) (runtime.Codec, error) {
+	mediaType, _, err := mime.ParseMediaType(opts.StorageMediaType)
 	if err != nil {
-		return nil, fmt.Errorf("%q is not a valid mime-type", storageMediaType)
+		return nil, fmt.Errorf("%q is not a valid mime-type", opts.StorageMediaType)
 	}
-	serializer, ok := runtime.SerializerInfoForMediaType(ns.SupportedMediaTypes(), mediaType)
+	serializer, ok := runtime.SerializerInfoForMediaType(opts.StorageSerializer.SupportedMediaTypes(), mediaType)
 	if !ok {
-		return nil, fmt.Errorf("unable to find serializer for %q", storageMediaType)
+		return nil, fmt.Errorf("unable to find serializer for %q", opts.StorageMediaType)
 	}
 
 	s := serializer.Serializer
 
 	// etcd2 only supports string data - we must wrap any result before returning
 	// TODO: storagebackend should return a boolean indicating whether it supports binary data
-	if !serializer.EncodesAsText && (config.Type == storagebackend.StorageTypeUnset || config.Type == storagebackend.StorageTypeETCD2) {
+	if !serializer.EncodesAsText && (opts.Config.Type == storagebackend.StorageTypeUnset || opts.Config.Type == storagebackend.StorageTypeETCD2) {
 		glog.V(4).Infof("Wrapping the underlying binary storage serializer with a base64 encoding for etcd2")
 		s = runtime.NewBase64Serializer(s)
 	}
 
-	encoder := ns.EncoderForVersion(
-		s,
+	// Give callers the opportunity to wrap encoders and decoders.  For decoders, each returned decoder will
+	// be passed to the recognizer so that multiple decoders are available.
+	var encoder runtime.Encoder = s
+	if opts.EncoderDecoratorFn != nil {
+		encoder = opts.EncoderDecoratorFn(encoder)
+	}
+	decoders := []runtime.Decoder{s, opts.StorageSerializer.UniversalDeserializer()}
+	if opts.DecoderDecoratorFn != nil {
+		decoders = opts.DecoderDecoratorFn(decoders)
+	}
+
+	// Ensure the storage receives the correct version.
+	encoder = opts.StorageSerializer.EncoderForVersion(
+		encoder,
 		runtime.NewMultiGroupVersioner(
-			storageVersion,
-			schema.GroupKind{Group: storageVersion.Group},
-			schema.GroupKind{Group: memoryVersion.Group},
+			opts.StorageVersion,
+			schema.GroupKind{Group: opts.StorageVersion.Group},
+			schema.GroupKind{Group: opts.MemoryVersion.Group},
 		),
 	)
-
-	ds := recognizer.NewDecoder(s, ns.UniversalDeserializer())
-	decoder := ns.DecoderToVersion(
-		ds,
+	decoder := opts.StorageSerializer.DecoderToVersion(
+		recognizer.NewDecoder(decoders...),
 		runtime.NewMultiGroupVersioner(
-			memoryVersion,
-			schema.GroupKind{Group: memoryVersion.Group},
-			schema.GroupKind{Group: storageVersion.Group},
+			opts.MemoryVersion,
+			schema.GroupKind{Group: opts.MemoryVersion.Group},
+			schema.GroupKind{Group: opts.StorageVersion.Group},
 		),
 	)
 

pkg/genericapiserver/server/storage_factory_test.go

@@ -20,6 +20,7 @@ import (
 	"reflect"
 	"testing"
 
+	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apiserver/pkg/server/options"
 	"k8s.io/apiserver/pkg/storage/storagebackend"
@@ -27,6 +28,67 @@ import (
 	"k8s.io/kubernetes/pkg/apis/extensions"
 )
 
+type fakeNegotiater struct {
+	serializer, streamSerializer runtime.Serializer
+	framer                       runtime.Framer
+	types, streamTypes           []string
+}
+
+func (n *fakeNegotiater) SupportedMediaTypes() []runtime.SerializerInfo {
+	var out []runtime.SerializerInfo
+	for _, s := range n.types {
+		info := runtime.SerializerInfo{Serializer: n.serializer, MediaType: s, EncodesAsText: true}
+		for _, t := range n.streamTypes {
+			if t == s {
+				info.StreamSerializer = &runtime.StreamSerializerInfo{
+					EncodesAsText: true,
+					Framer:        n.framer,
+					Serializer:    n.streamSerializer,
+				}
+			}
+		}
+		out = append(out, info)
+	}
+	return out
+}
+
+func (n *fakeNegotiater) UniversalDeserializer() runtime.Decoder {
+	return n.serializer
+}
+
+func (n *fakeNegotiater) EncoderForVersion(serializer runtime.Encoder, gv runtime.GroupVersioner) runtime.Encoder {
+	return n.serializer
+}
+
+func (n *fakeNegotiater) DecoderToVersion(serializer runtime.Decoder, gv runtime.GroupVersioner) runtime.Decoder {
+	return n.serializer
+}
+
+func TestDefaultStorageFactory(t *testing.T) {
+	ns := &fakeNegotiater{types: []string{"test/test"}}
+	f := NewDefaultStorageFactory(storagebackend.Config{}, "test/test", ns, NewDefaultResourceEncodingConfig(), NewResourceConfig())
+	f.AddCohabitatingResources(schema.GroupResource{Resource: "test"}, schema.GroupResource{Resource: "test2", Group: "2"})
+	called := false
+	testEncoderChain := func(e runtime.Encoder) runtime.Encoder {
+		called = true
+		return e
+	}
+	f.AddSerializationChains(testEncoderChain, nil, schema.GroupResource{Resource: "test"})
+	f.SetEtcdLocation(schema.GroupResource{Resource: "*"}, []string{"/server2"})
+	f.SetEtcdPrefix(schema.GroupResource{Resource: "test"}, "/prefix_for_test")
+
+	config, err := f.NewConfig(schema.GroupResource{Resource: "test"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if config.Prefix != "/prefix_for_test" || !reflect.DeepEqual(config.ServerList, []string{"/server2"}) {
+		t.Errorf("unexpected config %#v", config)
+	}
+	if !called {
+		t.Errorf("expected encoder chain to be called")
+	}
+}
+
 func TestUpdateEtcdOverrides(t *testing.T) {
 	testCases := []struct {
 		resource schema.GroupResource