Example server/client for gRPC presentation in Go Meetup Berlin October 2016

greeter.proto

syntax = "proto3";

option go_package = "sisu.sh/go/pb";

message Baby {

	// Name of the baby
	string name = 1;

	// Expected birthdate
	string birthdate = 2;
}

message Greeting {

	// Text content of greeting
	string content = 1;
}

service BabyGreeter {
	// Greet greets the baby by also calculating the days until birthdate
	rpc Greet (Baby) returns (Greeting) {}
}

greeter_client.py

import grpc
import greeter_pb2

channel = grpc.insecure_channel('localhost:5999')
stub = greeter_pb2.BabyGreeterStub(channel)
baby = greeter_pb2.Baby(
    name="Leyla",
    birthdate="2017-03-20"
)
greeting = stub.Greet(baby)
print(greeting.content)

greeter_service.go

package main

import (
	"fmt"
	"log"
	"net"
	"time"

	"golang.org/x/net/context"
	"google.golang.org/grpc"

	"sisu.sh/go/pb"
)

// GreeterService is the struct for Greeter service implementation
type GreeterService struct{}

// Greet greets user
func (s *GreeterService) Greet(ctx context.Context, in *pb.Baby) (*pb.Greeting, error) {
	fmt.Printf("Received message %+v\n", in)

	t, err := time.Parse("2006-01-02", in.Birthdate)
	if err != nil {
		return nil, err
	}

	days := int(t.Sub(time.Now()).Hours() / 24)
	content := fmt.Sprintf("Hello %v, we will meet after %v days.", in.Name, days)

	return &pb.Greeting{Content: content}, nil
}

func main() {
	grpcs := grpc.NewServer()
	server := &GreeterService{}
	pb.RegisterBabyGreeterServer(grpcs, server)
	lis, err := net.Listen("tcp", ":5999")
	if err != nil {
		log.Fatal(err)
	}
	grpcs.Serve(lis)
}