Add example & Update grpc readme

tools/goctl/example/rpc/hello.proto

@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package hello;
+
+option go_package = "./hello";
+
+message HelloReq {
+  string in = 1;
+}
+
+message HelloResp {
+  string msg = 1;
+}
+
+service Greet {
+  rpc SayHello(HelloReq) returns (HelloResp);
+}

tools/goctl/example/rpc/hello/etc/hello.yaml

@@ -0,0 +1,6 @@
+Name: hello.rpc
+ListenOn: 127.0.0.1:8080
+Etcd:
+  Hosts:
+  - 127.0.0.1:2379
+  Key: hello.rpc

tools/goctl/example/rpc/hello/hello.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+
+	"github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/internal/config"
+	greetServer "github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/internal/server/greet"
+	"github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/internal/svc"
+	"github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/pb/hello"
+
+	"github.com/zeromicro/go-zero/core/conf"
+	"github.com/zeromicro/go-zero/core/service"
+	"github.com/zeromicro/go-zero/zrpc"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/reflection"
+)
+
+var configFile = flag.String("f", "etc/hello.yaml", "the config file")
+
+func main() {
+	flag.Parse()
+
+	var c config.Config
+	conf.MustLoad(*configFile, &c)
+	ctx := svc.NewServiceContext(c)
+
+	s := zrpc.MustNewServer(c.RpcServerConf, func(grpcServer *grpc.Server) {
+		hello.RegisterGreetServer(grpcServer, greetServer.NewGreetServer(ctx))
+
+		if c.Mode == service.DevMode || c.Mode == service.TestMode {
+			reflection.Register(grpcServer)
+		}
+	})
+	defer s.Stop()
+
+	fmt.Printf("Starting rpc server at %s...\n", c.ListenOn)
+	s.Start()
+}

tools/goctl/example/rpc/hello/internal/config/config.go

@@ -0,0 +1,7 @@
+package config
+
+import "github.com/zeromicro/go-zero/zrpc"
+
+type Config struct {
+	zrpc.RpcServerConf
+}

tools/goctl/example/rpc/hello/internal/logic/greet/sayhellologic.go

@@ -0,0 +1,30 @@
+package greetlogic
+
+import (
+	"context"
+
+	"github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/internal/svc"
+	"github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/pb/hello"
+
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type SayHelloLogic struct {
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+	logx.Logger
+}
+
+func NewSayHelloLogic(ctx context.Context, svcCtx *svc.ServiceContext) *SayHelloLogic {
+	return &SayHelloLogic{
+		ctx:    ctx,
+		svcCtx: svcCtx,
+		Logger: logx.WithContext(ctx),
+	}
+}
+
+func (l *SayHelloLogic) SayHello(in *hello.HelloReq) (*hello.HelloResp, error) {
+	// todo: add your logic here and delete this line
+
+	return &hello.HelloResp{}, nil
+}

tools/goctl/example/rpc/hello/internal/svc/servicecontext.go

@@ -0,0 +1,13 @@
+package svc
+
+import "github.com/zeromicro/go-zero/tools/goctl/example/rpc/hello/internal/config"
+
+type ServiceContext struct {
+	Config config.Config
+}
+
+func NewServiceContext(c config.Config) *ServiceContext {
+	return &ServiceContext{
+		Config: c,
+	}
+}