Make gogo optional at compile time

README.md

@@ -18,3 +18,9 @@ As a containerd sub-project, you will find the:
  * and [Contributing guidelines](https://github.com/containerd/project/blob/main/CONTRIBUTING.md)
 
 information in our [`containerd/project`](https://github.com/containerd/project) repository.
+
+## Optional
+
+By default, support for gogoproto is available along side the standard Google
+protobuf types.
+You can choose to leave gogo support out by using the `!no_gogo` build tag.

go.sum

@@ -1,6 +1,5 @@
 github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
-github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
@@ -33,6 +32,5 @@ golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
 google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=

types.go

@@ -24,7 +24,6 @@ import (
 	"reflect"
 	"sync"
 
-	gogoproto "github.com/gogo/protobuf/proto"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/reflect/protoregistry"
 	"google.golang.org/protobuf/types/known/anypb"
@@ -33,8 +32,16 @@ import (
 var (
 	mu       sync.RWMutex
 	registry = make(map[reflect.Type]string)
+	handlers []handler
 )
 
+type handler interface {
+	Marshaller(interface{}) func() ([]byte, error)
+	Unmarshaller(interface{}) func([]byte) error
+	TypeURL(interface{}) string
+	GetType(url string) reflect.Type
+}
+
 // Definitions of common error types used throughout typeurl.
 //
 // These error types are used with errors.Wrap and errors.Wrapf to add context
@@ -112,9 +119,12 @@ func TypeURL(v interface{}) (string, error) {
 		switch t := v.(type) {
 		case proto.Message:
 			return string(t.ProtoReflect().Descriptor().FullName()), nil
-		case gogoproto.Message:
-			return gogoproto.MessageName(t), nil
 		default:
+			for _, h := range handlers {
+				if u := h.TypeURL(v); u != "" {
+					return u, nil
+				}
+			}
 			return "", fmt.Errorf("type %s: %w", reflect.TypeOf(v), ErrNotFound)
 		}
 	}
@@ -149,12 +159,19 @@ func MarshalAny(v interface{}) (Any, error) {
 		marshal = func(v interface{}) ([]byte, error) {
 			return proto.Marshal(t)
 		}
-	case gogoproto.Message:
-		marshal = func(v interface{}) ([]byte, error) {
-			return gogoproto.Marshal(t)
-		}
 	default:
-		marshal = json.Marshal
+		for _, h := range handlers {
+			if m := h.Marshaller(v); m != nil {
+				marshal = func(v interface{}) ([]byte, error) {
+					return m()
+				}
+				break
+			}
+		}
+
+		if marshal == nil {
+			marshal = json.Marshal
+		}
 	}
 
 	url, err := TypeURL(v)
@@ -229,7 +246,7 @@ func unmarshal(typeURL string, value []byte, v interface{}) (interface{}, error)
 	}
 
 	if v == nil {
-		v = reflect.New(t.t).Interface()
+		v = reflect.New(t).Interface()
 	} else {
 		// Validate interface type provided by client
 		vURL, err := TypeURL(v)
@@ -241,51 +258,45 @@ func unmarshal(typeURL string, value []byte, v interface{}) (interface{}, error)
 		}
 	}
 
-	if t.isProto {
-		switch t := v.(type) {
-		case proto.Message:
-			err = proto.Unmarshal(value, t)
-		case gogoproto.Message:
-			err = gogoproto.Unmarshal(value, t)
-		}
-	} else {
-		err = json.Unmarshal(value, v)
+	pm, ok := v.(proto.Message)
+	if ok {
+		return v, proto.Unmarshal(value, pm)
 	}
 
-	return v, err
-}
+	for _, h := range handlers {
+		if unmarshal := h.Unmarshaller(v); unmarshal != nil {
+			return v, unmarshal(value)
+		}
+	}
 
-type urlType struct {
-	t       reflect.Type
-	isProto bool
+	// fallback to json unmarshaller
+	return v, json.Unmarshal(value, v)
 }
 
-func getTypeByUrl(url string) (urlType, error) {
+func getTypeByUrl(url string) (reflect.Type, error) {
 	mu.RLock()
 	for t, u := range registry {
 		if u == url {
 			mu.RUnlock()
-			return urlType{
-				t: t,
-			}, nil
+			return t, nil
 		}
 	}
 	mu.RUnlock()
-	// fallback to proto registry
-	t := gogoproto.MessageType(url)
-	if t != nil {
-		return urlType{
-			// get the underlying Elem because proto returns a pointer to the type
-			t:       t.Elem(),
-			isProto: true,
-		}, nil
-	}
 	mt, err := protoregistry.GlobalTypes.FindMessageByURL(url)
 	if err != nil {
-		return urlType{}, fmt.Errorf("type with url %s: %w", url, ErrNotFound)
+		e := protoregistry.NotFound
+		if !errors.Is(err, e) {
+			return nil, fmt.Errorf("type with url %s: %w", url, ErrNotFound)
+		}
+
+		for _, h := range handlers {
+			if t := h.GetType(url); t != nil {
+				return t, nil
+			}
+		}
 	}
 	empty := mt.New().Interface()
-	return urlType{t: reflect.TypeOf(empty).Elem(), isProto: true}, nil
+	return reflect.TypeOf(empty).Elem(), nil
 }
 
 func tryDereference(v interface{}) reflect.Type {

types_gogo.go

@@ -0,0 +1,68 @@
+//go:build !no_gogo
+
+/*
+   Copyright The containerd 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 typeurl
+
+import (
+	"reflect"
+
+	gogoproto "github.com/gogo/protobuf/proto"
+)
+
+func init() {
+	handlers = append(handlers, gogoHandler{})
+}
+
+type gogoHandler struct{}
+
+func (gogoHandler) Marshaller(v interface{}) func() ([]byte, error) {
+	pm, ok := v.(gogoproto.Message)
+	if !ok {
+		return nil
+	}
+	return func() ([]byte, error) {
+		return gogoproto.Marshal(pm)
+	}
+}
+
+func (gogoHandler) Unmarshaller(v interface{}) func([]byte) error {
+	pm, ok := v.(gogoproto.Message)
+	if !ok {
+		return nil
+	}
+
+	return func(dt []byte) error {
+		return gogoproto.Unmarshal(dt, pm)
+	}
+}
+
+func (gogoHandler) TypeURL(v interface{}) string {
+	pm, ok := v.(gogoproto.Message)
+	if !ok {
+		return ""
+	}
+	return gogoproto.MessageName(pm)
+}
+
+func (gogoHandler) GetType(url string) reflect.Type {
+	t := gogoproto.MessageType(url)
+	if t == nil {
+		return nil
+	}
+	return t.Elem()
+}

types_test.go

@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/gogo/protobuf/proto"
-	gogotypes "github.com/gogo/protobuf/types"
 	"google.golang.org/protobuf/types/known/anypb"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
@@ -37,7 +36,6 @@ func clear() {
 	registry = make(map[reflect.Type]string)
 }
 
-var _ Any = &gogotypes.Any{}
 var _ Any = &anypb.Any{}
 
 func TestRegisterPointerGetPointer(t *testing.T) {