From e83572b9941e0497db4a2e4be7b384df57687f90 Mon Sep 17 00:00:00 2001
From: Asim Aslam <asim@aslam.me>
Date: Tue, 18 Jun 2019 18:51:52 +0100
Subject: [PATCH] Add working grpc proxy config

---
 codec.go    | 28 ++++++++++------------------
 grpc.go     | 20 ++++++++++++--------
 request.go  | 20 +++++---------------
 response.go | 10 ++++++++--
 4 files changed, 35 insertions(+), 43 deletions(-)

diff --git a/codec.go b/codec.go
index 97f0551..62f3038 100644
--- a/codec.go
+++ b/codec.go
@@ -10,8 +10,8 @@ import (
 	"github.com/micro/go-micro/codec/bytes"
 	"github.com/micro/go-micro/codec/jsonrpc"
 	"github.com/micro/go-micro/codec/protorpc"
-	"google.golang.org/grpc/encoding"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/encoding"
 )
 
 type jsonCodec struct{}
@@ -123,9 +123,9 @@ func (jsonCodec) Name() string {
 
 type grpcCodec struct {
 	// headers
-	id string
-	target string
-	method string
+	id       string
+	target   string
+	method   string
 	endpoint string
 
 	s grpc.ClientStream
@@ -154,27 +154,19 @@ func (g *grpcCodec) ReadHeader(m *codec.Message, mt codec.MessageType) error {
 }
 
 func (g *grpcCodec) ReadBody(v interface{}) error {
-	frame := &bytes.Frame{}
-	if err := g.s.RecvMsg(frame); err != nil {
-		return err
+	if f, ok := v.(*bytes.Frame); ok {
+		return g.s.RecvMsg(f)
 	}
-	return g.c.Unmarshal(frame.Data, v)
+	return g.s.RecvMsg(v)
 }
 
 func (g *grpcCodec) Write(m *codec.Message, v interface{}) error {
 	// if we don't have a body
-	if len(m.Body) == 0 {
-		b, err := g.c.Marshal(v)
-		if err != nil {
-			return err
-		}
-		m.Body = b
+	if v != nil {
+		return g.s.SendMsg(v)
 	}
-
-	// create an encoded frame
-	frame := &bytes.Frame{m.Body}
 	// write the body using the framing codec
-	return g.s.SendMsg(frame)
+	return g.s.SendMsg(&bytes.Frame{m.Body})
 }
 
 func (g *grpcCodec) Close() error {
diff --git a/grpc.go b/grpc.go
index 7a8aacf..ac1dc82 100644
--- a/grpc.go
+++ b/grpc.go
@@ -32,8 +32,9 @@ type grpcClient struct {
 }
 
 func init() {
-	encoding.RegisterCodec(jsonCodec{})
-	encoding.RegisterCodec(bytesCodec{})
+	encoding.RegisterCodec(wrapCodec{jsonCodec{}})
+	encoding.RegisterCodec(wrapCodec{jsonCodec{}})
+	encoding.RegisterCodec(wrapCodec{bytesCodec{}})
 }
 
 // secure returns the dial option for whether its a secure or insecure connection
@@ -129,7 +130,7 @@ func (g *grpcClient) call(ctx context.Context, node *registry.Node, req client.R
 	ch := make(chan error, 1)
 
 	go func() {
-		err := cc.Invoke(ctx, methodToGRPC(req.Endpoint(), req.Body()), req.Body(), rsp, grpc.ForceCodec(cf))
+		err := cc.Invoke(ctx, methodToGRPC(req.Service(), req.Endpoint()), req.Body(), rsp, grpc.ForceCodec(cf))
 		ch <- microError(err)
 	}()
 
@@ -191,23 +192,26 @@ func (g *grpcClient) stream(ctx context.Context, node *registry.Node, req client
 		ServerStreams: true,
 	}
 
-	st, err := cc.NewStream(ctx, desc, methodToGRPC(req.Endpoint(), req.Body()))
+	st, err := cc.NewStream(ctx, desc, methodToGRPC(req.Service(), req.Endpoint()))
 	if err != nil {
 		return nil, errors.InternalServerError("go.micro.client", fmt.Sprintf("Error creating stream: %v", err))
 	}
 
+	codec := &grpcCodec{
+		s: st,
+		c: wc,
+	}
+
 	// set request codec
 	if r, ok := req.(*grpcRequest); ok {
-		r.codec = &grpcCodec{
-			s: st,
-			c: wc,
-		}
+		r.codec = codec
 	}
 
 	rsp := &response{
 		conn:   cc,
 		stream: st,
 		codec:  cf,
+		gcodec: codec,
 	}
 
 	return &grpcStream{
diff --git a/request.go b/request.go
index cb14a33..94b44da 100644
--- a/request.go
+++ b/request.go
@@ -2,7 +2,6 @@ package grpc
 
 import (
 	"fmt"
-	"reflect"
 	"strings"
 
 	"github.com/micro/go-micro/client"
@@ -18,30 +17,21 @@ type grpcRequest struct {
 	codec       codec.Codec
 }
 
-func methodToGRPC(method string, request interface{}) string {
+// service Struct.Method /service.Struct/Method
+func methodToGRPC(service, method string) string {
 	// no method or already grpc method
 	if len(method) == 0 || method[0] == '/' {
 		return method
 	}
-	// can't operate on nil request
-	t := reflect.TypeOf(request)
-	if t == nil {
-		return method
-	}
-	// dereference
-	if t.Kind() == reflect.Ptr {
-		t = t.Elem()
-	}
-	// get package name
-	pParts := strings.Split(t.PkgPath(), "/")
-	pkg := pParts[len(pParts)-1]
+
 	// assume method is Foo.Bar
 	mParts := strings.Split(method, ".")
 	if len(mParts) != 2 {
 		return method
 	}
+
 	// return /pkg.Foo/Bar
-	return fmt.Sprintf("/%s.%s/%s", pkg, mParts[0], mParts[1])
+	return fmt.Sprintf("/%s.%s/%s", service, mParts[0], mParts[1])
 }
 
 func newGRPCRequest(service, method string, request interface{}, contentType string, reqOpts ...client.RequestOption) client.Request {
diff --git a/response.go b/response.go
index 7ef7224..c870fad 100644
--- a/response.go
+++ b/response.go
@@ -4,6 +4,7 @@ import (
 	"strings"
 
 	"github.com/micro/go-micro/codec"
+	"github.com/micro/go-micro/codec/bytes"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/encoding"
 )
@@ -12,11 +13,12 @@ type response struct {
 	conn   *grpc.ClientConn
 	stream grpc.ClientStream
 	codec  encoding.Codec
+	gcodec codec.Codec
 }
 
 // Read the response
 func (r *response) Codec() codec.Reader {
-	return nil
+	return r.gcodec
 }
 
 // read the header
@@ -34,5 +36,9 @@ func (r *response) Header() map[string]string {
 
 // Read the undecoded response
 func (r *response) Read() ([]byte, error) {
-	return nil, nil
+	f := &bytes.Frame{}
+	if err := r.gcodec.ReadBody(f); err != nil {
+		return nil, err
+	}
+	return f.Data, nil
 }