main.go

package main

import (
	"context"
	"fmt"
	"net"
	"os"
	"time"

	log "github.com/sirupsen/logrus"
	"google.golang.org/grpc"

	"gitlab.dafni.rl.ac.uk/dafni/tools/rpctest/pkg/rpctest"
)

func main() {
	var m string
	var isset bool
	if m, isset = os.LookupEnv("MODE"); !isset {
		log.Fatal("need to set env var $MODE to either client or server")
	}
	switch m {
	case "server":
		lis, err := net.Listen("unix", "rpctest.sock")
		if err != nil {
			log.WithError(err).Fatal("bad listen")
		}
		grpcServer := grpc.NewServer()
		s := &rpctest.RPCTestServer{}
		rpctest.RegisterRpcTestServer(grpcServer, s)
		grpcServer.Serve(lis)
	case "client":
		conn, err := grpc.Dial("unix:./rpctest.sock", grpc.WithInsecure())
		if err != nil {
			log.WithError(err).Fatal("cant dial server")
		}
		cl, err := rpctest.NewRpcTestClient(conn).ReportStatus(context.Background())
		if err != nil {
			log.WithError(err).Fatal("cant create rpc rs client")
		}
		i := 5
		for i > 0 {
			log.Printf("sending %d", i)
			err := cl.Send(&rpctest.StatusReport{
				Status: fmt.Sprintf("my number is %d", i),
			})
			if err != nil {
				log.WithError(err).Fatal("bad send")
			}
			i--
			time.Sleep(1 * time.Second)
		}
		repl, err := cl.CloseAndRecv()
		if err != nil {
			log.WithError(err).Error("bad reply")
		}
		log.Printf("got reply: %+v", repl)
	}
}

rpctest.proto

syntax = "proto3";

service RpcTest {
    rpc ReportStatus(stream StatusReport) returns (StatusReply) {}
}

message StatusReport {
    string status = 1;
}

message StatusReply {
    string reply = 1;
}

server.go

package rpctest

import (
	"io"

	log "github.com/sirupsen/logrus"
)

type RPCTestServer struct {
}

func (r *RPCTestServer) ReportStatus(stream RpcTest_ReportStatusServer) error {
	for {
		rep, err := stream.Recv()
		if err == io.EOF {
			log.Printf("Got the last message")
			return stream.SendAndClose(&StatusReply{
				Reply: "thanks",
			})
		} else if err != nil {
			return err
		}
		log.Printf("got message: %+v", rep)
	}
}

vpn-3-104% tree
.
├── Makefile
├── cmd
│   └── rpctest
│       └── main.go
├── go.mod
├── go.sum
├── pkg
│   └── rpctest
│       ├── rpctest.pb.go
│       ├── rpctest.proto
│       └── server.go
├── rpctest
└── rpctest.sock

4 directories, 9 files

vpn-3-104% protoc pkg/rpctest/rpctest.proto --go_out=plugins=grpc:.