gRPC Server and Client in Golang
code snippet
A sample from a Medium post 1.
# init
go mod init github.com/igorlima/grpc-sample
go get google.golang.org/grpc
go get github.com/golang/protobuf/protoc-gen-go
go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.28
go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.2
go.mod
module github.com/igorlima/grpc-sample
go 1.18
require (
github.com/golang/protobuf v1.5.3 // indirect
golang.org/x/net v0.9.0 // indirect
golang.org/x/sys v0.7.0 // indirect
golang.org/x/text v0.9.0 // indirect
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
google.golang.org/grpc v1.56.2 // indirect
google.golang.org/protobuf v1.31.0 // indirect
)
syntax = "proto3";
package main;
option go_package = "./grpcsample";
service HelloService {
rpc SayHello (HelloRequest) returns (HelloResponse) {}
}
message HelloRequest {
string name = 1;
}
message HelloResponse {
string message = 1;
}
# generate Go code from the protobuf definition
protoc --go_out=. --go-grpc_out=. hello.proto
server.go
package main
import (
"context"
"log"
"net"
pb "github.com/igorlima/grpc-sample/grpcsample"
"google.golang.org/grpc"
)
type server struct {
pb.UnimplementedHelloServiceServer
}
func (s *server) SayHello(ctx context.Context, req *pb.HelloRequest) (*pb.HelloResponse, error) {
return &pb.HelloResponse{Message: "Hello, " + req.Name}, nil
}
func main() {
lis, err := net.Listen("tcp", ":50051")
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
s := grpc.NewServer()
pb.RegisterHelloServiceServer(s, &server{})
if err := s.Serve(lis); err != nil {
log.Fatalf("failed to serve: %v", err)
}
}
client.go
package main
import (
"context"
"log"
pb "github.com/igorlima/grpc-sample/grpcsample"
"google.golang.org/grpc"
)
func main() {
conn, err := grpc.Dial("localhost:50051", grpc.WithInsecure())
if err != nil {
log.Fatalf("did not connect: %v", err)
}
defer conn.Close()
c := pb.NewHelloServiceClient(conn)
name := "John"
res, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
if err != nil {
log.Fatalf("could not greet: %v", err)
}
log.Printf("Response: %s", res.Message)
}
# run the gRPC server
go run server.go
# in a separate terminal, run the gRPC client:
go run client.go