feat: support json protocol with grpc

- add client conf
- support json codec

Closes #436

protocol/grpc/client.go

@@ -25,14 +25,53 @@ import (
 	"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
 	"github.com/opentracing/opentracing-go"
 	"google.golang.org/grpc"
+	"gopkg.in/yaml.v2"
 )
 
 import (
 	"github.com/apache/dubbo-go/common"
 	"github.com/apache/dubbo-go/common/constant"
+	"github.com/apache/dubbo-go/common/logger"
 	"github.com/apache/dubbo-go/config"
 )
 
+var (
+	clientConf *ClientConfig
+)
+
+func init() {
+	// load clientconfig from consumer_config
+	// default use grpc
+	consumerConfig := config.GetConsumerConfig()
+	if consumerConfig.ApplicationConfig == nil {
+		return
+	}
+	protocolConf := config.GetConsumerConfig().ProtocolConf
+	defaultClientConfig := GetDefaultClientConfig()
+	if protocolConf == nil {
+		logger.Info("protocol_conf default use dubbo config")
+	} else {
+		grpcConf := protocolConf.(map[interface{}]interface{})[GRPC]
+		if grpcConf == nil {
+			logger.Warnf("grpcConf is nil")
+			return
+		}
+		grpcConfByte, err := yaml.Marshal(grpcConf)
+		if err != nil {
+			panic(err)
+		}
+		err = yaml.Unmarshal(grpcConfByte, &defaultClientConfig)
+		if err != nil {
+			panic(err)
+		}
+	}
+	clientConf = &defaultClientConfig
+	if err := clientConf.Validate(); err != nil {
+		logger.Warnf("[CheckValidity] error: %v", err)
+		return
+	}
+}
+
 // Client ...
 type Client struct {
 	*grpc.ClientConn
@@ -43,9 +82,11 @@ type Client struct {
 func NewClient(url common.URL) *Client {
 	// if global trace instance was set , it means trace function enabled. If not , will return Nooptracer
 	tracer := opentracing.GlobalTracer()
-	conn, err := grpc.Dial(url.Location, grpc.WithInsecure(), grpc.WithBlock(),
-		grpc.WithUnaryInterceptor(
-			otgrpc.OpenTracingClientInterceptor(tracer, otgrpc.LogPayloads())))
+	dailOpts := make([]grpc.DialOption, 0)
+	dailOpts = append(dailOpts, grpc.WithInsecure(), grpc.WithBlock(), grpc.WithUnaryInterceptor(
+		otgrpc.OpenTracingClientInterceptor(tracer, otgrpc.LogPayloads())),
+		grpc.WithDefaultCallOptions(grpc.CallContentSubtype(clientConf.ContentType)))
+	conn, err := grpc.Dial(url.Location, dailOpts...)
 	if err != nil {
 		panic(err)
 	}

protocol/grpc/codec.go

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 grpc
+
+
+import (
+	"bytes"
+	"encoding/json"
+)
+
+import (
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/grpc/encoding"
+)
+
+func init() {
+	encoding.RegisterCodec(JSON{
+		Marshaler: jsonpb.Marshaler{
+			EmitDefaults: true,
+			OrigName:     true,
+		},
+	})
+}
+
+type JSON struct {
+	jsonpb.Marshaler
+	jsonpb.Unmarshaler
+}
+
+func (_ JSON) Name() string {
+	return "json"
+}
+
+func (j JSON) Marshal(v interface{}) (out []byte, err error) {
+	if pm, ok := v.(proto.Message); ok {
+		b := new(bytes.Buffer)
+		err := j.Marshaler.Marshal(b, pm)
+		if err != nil {
+			return nil, err
+		}
+		return b.Bytes(), nil
+	}
+	return json.Marshal(v)
+}
+
+func (j JSON) Unmarshal(data []byte, v interface{}) (err error) {
+	if pm, ok := v.(proto.Message); ok {
+		b := bytes.NewBuffer(data)
+		return j.Unmarshaler.Unmarshal(b, pm)
+	}
+	return json.Unmarshal(data, v)
+}

protocol/grpc/config.go

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 grpc
+
+type (
+	// ServerConfig
+	ServerConfig struct {
+	}
+
+	// ClientConfig
+	ClientConfig struct {
+		// content type, more information refer by https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
+		ContentType string `default:"application/grpc+proto" yaml:"content_type" json:"content_type,omitempty"`
+	}
+)
+
+// GetDefaultClientConfig ...
+func GetDefaultClientConfig() ClientConfig {
+	return ClientConfig{
+		ContentType: "application/grpc+proto",
+	}
+}
+
+// GetDefaultServerConfig ...
+func GetDefaultServerConfig() ServerConfig {
+	return ServerConfig{
+	}
+}
+
+func (c *ClientConfig) Validate() error {
+	return nil
+}
+
+func (c *ServerConfig) Validate() error {
+	return nil
+}