From c17d0fcc0f5d4f06b953f42202b2818dc692303c Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Sun, 13 Jan 2019 19:54:07 +0000
Subject: [PATCH] grpc request

---
 client/rpc_codec.go  |  4 ++++
 codec/grpc/grpc.go   | 23 ++++++++++++++++++-----
 server/rpc_server.go |  4 ++--
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/client/rpc_codec.go b/client/rpc_codec.go
index 647d044b..a7e9dada 100644
--- a/client/rpc_codec.go
+++ b/client/rpc_codec.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/micro/go-micro/codec"
 	raw "github.com/micro/go-micro/codec/bytes"
+	"github.com/micro/go-micro/codec/grpc"
 	"github.com/micro/go-micro/codec/json"
 	"github.com/micro/go-micro/codec/jsonrpc"
 	"github.com/micro/go-micro/codec/proto"
@@ -48,6 +49,9 @@ var (
 	DefaultContentType = "application/protobuf"
 
 	DefaultCodecs = map[string]codec.NewCodec{
+		"application/grpc":         grpc.NewCodec,
+		"application/grpc+json":    grpc.NewCodec,
+		"application/grpc+proto":   grpc.NewCodec,
 		"application/protobuf":     proto.NewCodec,
 		"application/json":         json.NewCodec,
 		"application/json-rpc":     jsonrpc.NewCodec,
diff --git a/codec/grpc/grpc.go b/codec/grpc/grpc.go
index 79c30f4b..732f0356 100644
--- a/codec/grpc/grpc.go
+++ b/codec/grpc/grpc.go
@@ -4,6 +4,7 @@ package grpc
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"strings"
 
@@ -77,8 +78,23 @@ func (c *Codec) Write(m *codec.Message, b interface{}) error {
 		c.ContentType = ct
 	}
 
-	m.Header["Trailer"] = "grpc-status, grpc-message"
+	switch m.Type {
+	case codec.Request:
+		parts := strings.Split(m.Endpoint, ".")
+		m.Header[":method"] = "POST"
+		m.Header[":path"] = fmt.Sprintf("/%s.%s/%s", m.Target, parts[0], parts[1])
+		m.Header[":proto"] = "HTTP/2.0"
+		m.Header["te"] = "trailers"
+		m.Header["user-agent"] = "grpc-go/1.0.0"
+		m.Header[":authority"] = m.Target
+		m.Header["content-type"] = c.ContentType
+	case codec.Response:
+		m.Header["Trailer"] = "grpc-status, grpc-message"
+		m.Header["grpc-status"] = "0"
+		m.Header["grpc-message"] = ""
+	}
 
+	// marshal content
 	switch c.ContentType {
 	case "application/grpc+json":
 		buf, err = json.Marshal(b)
@@ -90,16 +106,13 @@ func (c *Codec) Write(m *codec.Message, b interface{}) error {
 	default:
 		err = errors.New("Unsupported Content-Type")
 	}
-
+	// check error
 	if err != nil {
 		m.Header["grpc-status"] = "8"
 		m.Header["grpc-message"] = err.Error()
 		return err
 	}
 
-	m.Header["grpc-status"] = "0"
-	m.Header["grpc-message"] = ""
-
 	return encode(0, buf, c.Conn)
 }
 
diff --git a/server/rpc_server.go b/server/rpc_server.go
index 93b49d4d..d02e8421 100644
--- a/server/rpc_server.go
+++ b/server/rpc_server.go
@@ -153,8 +153,8 @@ func (s *rpcServer) ServeConn(sock transport.Socket) {
 			// write an error response
 			rcodec.Write(&codec.Message{
 				Header: msg.Header,
-				Error: err.Error(),
-				Type: codec.Error,
+				Error:  err.Error(),
+				Type:   codec.Error,
 			}, nil)
 
 			s.wg.Done()