# README

tRPC-Go grpc protocol

The tRPC-Go framework achieves the purpose of supporting the grpc protocol through package introduction and grpc server encapsulation. It supports grpc server to process grpc client requests through grpc server transport and codec.

Quick start

The following is the creation of a sample demo to demonstrate the usage process.

Suppose our current business project app is test, and the service server we want to develop is hellogrpc.

The git project used is http://git.woa.com/trpc-go/trpc-codec.git, and this example is placed under the grpc/examples path under the project.

During the operation, you can set your own app and server name, but you need to pay attention to the replacement of the corresponding fields in the subsequent steps.

Preparation

An environment with a golang compilation environment (golang 1.11 or later).
Install trpc tool
Install grpc_cli tool

Start

clone project: git clone "http://git.woa.com/trpc-go/trpc-codec.git"
cd trpc-codec/grpc/examples
mkdir hellogrpc && cd hellogrpc && mkdir protocol
init golang mod：go mod init git.code.oa.com/trpc-go/trpc-codec/grpc/examples/hellogrpc
On the protocol path, write the service agreement file vim protocol/hellogrpc.proto：

syntax = "proto3";  
package trpc.app.server;
option go_package="trpc.group/trpc-go/trpc-codec/grpc/testdata/protocols/streams";

message Req {
  string msg = 1;
}

message Rsp {
  string msg = 1;
}

service Greeter {
  rpc Hello(Req) returns (Rsp) {}
  rpc GetStream (Req) returns (stream Rsp){}
  rpc PutStream (stream Req) returns (Rsp){}
  rpc AllStream (stream Req) returns (stream Rsp){}
}

> **Pay attention to the definition of package and go_package in proto, for details, please refer to [tRPC-Go Code of Conduct](https://iwiki.oa.tencent.com/pages/viewpage.action?pageId=99485634). **

6. Generate a serving model via the command line: trpc create --protocol=grpc --protofile=protocol/hellogrpc.proto --output .. ！！！Note: Please use the trpc command line tool of v0.3.17 and later versions to enable grpc protocol support. If you want to use the trpc library to implement the grpc client, please use the trpc command line tool of v0.4.1 and later versions. 7. In order to facilitate testing, replace the remote protocol with local go mod edit -replace=git.code.oa.com/trpc-go/trpc-codec/grpc/examples/hellogrpc/protocol=./stub/git.code.oa.com/trpc-go/trpc-codec/grpc/examples/hellogrpc/protocol

Write business logic:

Modify main.go, add trpc-grpc package, and register in the main function:

It will be modified to be directly supported by the trpc tool in the future, and it needs to be manually introduced and registered for the time being
```
// Import library files
import "git.code.oa.com/trpc-go/trpc-codec/grpc"
...
func main() {

	s := trpc.NewServer()

	pb.RegisterGreeterService(s, &greeterServiceImpl{})

	s.Serve()
}
```

Modify the greeter.go file of the service interface, as follows:

// Package main is the main package.
package main

import (
	"context"

	pb "trpc.group/trpc-go/trpc-codec/grpc/examples/hellogrpc/protocol"
)

// SayHello ...
func (s *greeterServiceImpl) SayHello(ctx context.Context, req *pb.HelloRequest, rsp *pb.HelloReply) error {
	// implement business logic here ...
	// new content
	rsp.Msg = "hello grpc client: " + req.Msg

	return nil
}

// SayHi ...
func (s *greeterServiceImpl) SayHi(ctx context.Context, req *pb.HelloRequest, rsp *pb.HelloReply) error {
	// implement business logic here ...
	// new content
	rsp.Msg = "hi grpc client: " + req.Msg

	return nil
}

Compile: go build, will generate the executable file of hellogrpc.
Modify the protocol field under service in the startup configuration trpc_go.yaml file under the current path, from trpc to grpc:

  service:                                     # The service provided by the business service can have multiple
      - name: trpc.test.hellogrpc.Greeter      # service route name
        ip: 127.0.0.1                          # The service listens to the ip address. You can use the placeholder ${ip}, choose one of ip and nic, and give priority to ip
        #nic: eth0
        port: 8000                             # Service listening port can use placeholder ${port}
        network: tcp                           # Network monitoring type tcp/udp
        protocol: grpc                         # Change to grpc
        timeout: 1000                          # Request maximum processing time, at milliseconds

Start the service: ./hellogrpc &

Execute tests with grpc-cli:

# view service
$ grpc_cli ls localhost:8000
grpc.reflection.v1alpha.ServerReflection
trpc.test.hellogrpc.Greeter

# View details of the Greeter service
$ grpc_cli ls localhost:8000 trpc.test.hellogrpc.Greeter -l
filename: hellogrpc.proto
package: trpc.test.hellogrpc;
service Greeter {
  rpc SayHello(trpc.test.hellogrpc.HelloRequest) returns (trpc.test.hellogrpc.HelloReply) {}
  rpc SayHi(trpc.test.hellogrpc.HelloRequest) returns (trpc.test.hellogrpc.HelloReply) {}
}

# See the details of the Greeter.SayHi method
$ grpc_cli ls localhost:8000 trpc.test.hellogrpc.Greeter.SayHi -l
rpc SayHi(trpc.test.hellogrpc.HelloRequest) returns (trpc.test.hellogrpc.HelloReply) {}

# Debug Greeter.SayHi interface
$ grpc_cli call localhost:8000 'trpc.test.hellogrpc.Greeter.SayHi' "msg: 'I am a test.'"
msg: "hi grpc client: I am a test."
Rpc succeeded with OK status

Write client code Client code generated using grpc-go.

# Generate client code for grpc-go
$ protoc --go_out=plugins=grpc:. protocol/hellogrpc.proto

You can also use trpc to write client code, please use v0.4.1 and above trpc-go-cmdline to generate client stub code, refer to example/client/tgrpc to implement the client.