go 1.19 gRPC的简单实操

学习一段时间的grpc了，今天简单记录下grpc的使用流程。

在进入今天的分享前，请确保自己已经安装好相关的环境：

• go 1.19
• protoc v3.19.4
• protoc-gen-go v1.28.1
• protoc-gen-go-grpc v1.3.0

1.项目目录结构

如下图显示：

2.proto 文件-接口定义

这里我们以简单的 HelloSerivce 为切入点：

syntax = "proto3"; // 固定语法前缀
 
option go_package = "."; // 指定生成的go代码在你项目中的导入路径
 
package pb; // 包名
 
// 定义服务
service HelloService {
  // SayHello 方法
  rpc SayHello (HelloRequest) returns (HelloResponse) {}
}
 
// 请求消息
message HelloRequest {
  string name = 1;
}
 
// 响应消息
message HelloResponse {
  string reply = 1;
}

3.生成 pb.go 文件

在定义好接口后，我们就可以生成相关的对应的go代码了：

protoc --go_out=./proto --go-grpc_out=./proto pb/hello.proto
 
# 命令说明
- --go_out，指定 pb.go 文件生成到的目录
- --go-grpc_out，指定 grpc.pb.go 文件生成到的目录
- pb/hello.proto，指定用到的接口定义文件

一键生成后，可以看看相关的 pb.go文件：
hello.pb.go

// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
// 	protoc-gen-go v1.28.1
// 	protoc        v3.19.4
// source: pb/hello.proto
 
package proto
 
 
import (
	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
	reflect "reflect"
	sync "sync"
)
 
const (
	// Verify that this generated code is sufficiently up-to-date.
	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
	// Verify that runtime/protoimpl is sufficiently up-to-date.
	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)
 
// 请求消息
type HelloRequest struct {
	state         protoimpl.MessageState
	sizeCache     protoimpl.SizeCache
	unknownFields protoimpl.UnknownFields
 
	Name string `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
}
 
func (x *HelloRequest) Reset() {
	*x = HelloRequest{}
	if protoimpl.UnsafeEnabled {
		mi := &file_pb_hello_proto_msgTypes[0]
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		ms.StoreMessageInfo(mi)
	}
}
 
func (x *HelloRequest) String() string {
	return protoimpl.X.MessageStringOf(x)
}
 
func (*HelloRequest) ProtoMessage() {}
 
func (x *HelloRequest) ProtoReflect() protoreflect.Message {
	mi := &file_pb_hello_proto_msgTypes[0]
	if protoimpl.UnsafeEnabled && x != nil {
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		if ms.LoadMessageInfo() == nil {
			ms.StoreMessageInfo(mi)
		}
		return ms
	}
	return mi.MessageOf(x)
}
 
// Deprecated: Use HelloRequest.ProtoReflect.Descriptor instead.
func (*HelloRequest) Descriptor() ([]byte, []int) {
	return file_pb_hello_proto_rawDescGZIP(), []int{0}
}
 
func (x *HelloRequest) GetName() string {
	if x != nil {
		return x.Name
	}
	return ""
}
 
// 响应消息
type HelloResponse struct {
	state         protoimpl.MessageState
	sizeCache     protoimpl.SizeCache
	unknownFields protoimpl.UnknownFields
 
	Reply string `protobuf:"bytes,1,opt,name=reply,proto3" json:"reply,omitempty"`
}
 
func (x *HelloResponse) Reset() {
	*x = HelloResponse{}
	if protoimpl.UnsafeEnabled {
		mi := &file_pb_hello_proto_msgTypes[1]
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		ms.StoreMessageInfo(mi)
	}
}
 
func (x *HelloResponse) String() string {
	return protoimpl.X.MessageStringOf(x)
}
 
func (*HelloResponse) ProtoMessage() {}
 
func (x *HelloResponse) ProtoReflect() protoreflect.Message {
	mi := &file_pb_hello_proto_msgTypes[1]
	if protoimpl.UnsafeEnabled && x != nil {
		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
		if ms.LoadMessageInfo() == nil {
			ms.StoreMessageInfo(mi)
		}
		return ms
	}
	return mi.MessageOf(x)
}
 
// Deprecated: Use HelloResponse.ProtoReflect.Descriptor instead.
func (*HelloResponse) Descriptor() ([]byte, []int) {
	return file_pb_hello_proto_rawDescGZIP(), []int{1}
}
 
func (x *HelloResponse) GetReply() string {
	if x != nil {
		return x.Reply
	}
	return ""
}
 
var File_pb_hello_proto protoreflect.FileDescriptor
 
var file_pb_hello_proto_rawDesc = []byte{
	0x0a, 0x0e, 0x70, 0x62, 0x2f, 0x68, 0x65, 0x6c, 0x6c, 0x6f, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f,
	0x12, 0x02, 0x70, 0x62, 0x22, 0x22, 0x0a, 0x0c, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71,
	0x75, 0x65, 0x73, 0x74, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01,
	0x28, 0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x22, 0x25, 0x0a, 0x0d, 0x48, 0x65, 0x6c, 0x6c,
	0x6f, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x12, 0x14, 0x0a, 0x05, 0x72, 0x65, 0x70,
	0x6c, 0x79, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x05, 0x72, 0x65, 0x70, 0x6c, 0x79, 0x32,
	0x41, 0x0a, 0x0c, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x53, 0x65, 0x72, 0x76, 0x69, 0x63, 0x65, 0x12,
	0x31, 0x0a, 0x08, 0x53, 0x61, 0x79, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x12, 0x10, 0x2e, 0x70, 0x62,
	0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x11, 0x2e,
	0x70, 0x62, 0x2e, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65,
	0x22, 0x00, 0x42, 0x03, 0x5a, 0x01, 0x2e, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}
 
var (
	file_pb_hello_proto_rawDescOnce sync.Once
	file_pb_hello_proto_rawDescData = file_pb_hello_proto_rawDesc
)
 
func file_pb_hello_proto_rawDescGZIP() []byte {
	file_pb_hello_proto_rawDescOnce.Do(func() {
		file_pb_hello_proto_rawDescData = protoimpl.X.CompressGZIP(file_pb_hello_proto_rawDescData)
	})
	return file_pb_hello_proto_rawDescData
}
 
var file_pb_hello_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
var file_pb_hello_proto_goTypes = []interface{}{
	(*HelloRequest)(nil),  // 0: pb.HelloRequest
	(*HelloResponse)(nil), // 1: pb.HelloResponse
}
var file_pb_hello_proto_depIdxs = []int32{
	0, // 0: pb.HelloService.SayHello:input_type -> pb.HelloRequest
	1, // 1: pb.HelloService.SayHello:output_type -> pb.HelloResponse
	1, // [1:2] is the sub-list for method output_type
	0, // [0:1] is the sub-list for method input_type
	0, // [0:0] is the sub-list for extension type_name
	0, // [0:0] is the sub-list for extension extendee
	0, // [0:0] is the sub-list for field type_name
}
 
func init() { file_pb_hello_proto_init() }
func file_pb_hello_proto_init() {
	if File_pb_hello_proto != nil {
		return
	}
	if !protoimpl.UnsafeEnabled {
		file_pb_hello_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
			switch v := v.(*HelloRequest); i {
			case 0:
				return &v.state
			case 1:
				return &v.sizeCache
			case 2:
				return &v.unknownFields
			default:
				return nil
			}
		}
		file_pb_hello_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
			switch v := v.(*HelloResponse); i {
			case 0:
				return &v.state
			case 1:
				return &v.sizeCache
			case 2:
				return &v.unknownFields
			default:
				return nil
			}
		}
	}
	type x struct{}
	out := protoimpl.TypeBuilder{
		File: protoimpl.DescBuilder{
			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
			RawDescriptor: file_pb_hello_proto_rawDesc,
			NumEnums:      0,
			NumMessages:   2,
			NumExtensions: 0,
			NumServices:   1,
		},
		GoTypes:           file_pb_hello_proto_goTypes,
		DependencyIndexes: file_pb_hello_proto_depIdxs,
		MessageInfos:      file_pb_hello_proto_msgTypes,
	}.Build()
	File_pb_hello_proto = out.File
	file_pb_hello_proto_rawDesc = nil
	file_pb_hello_proto_goTypes = nil
	file_pb_hello_proto_depIdxs = nil
}

hello_grpc.pb.go

// Code generated by protoc-gen-go-grpc. DO NOT EDIT.
// versions:
// - protoc-gen-go-grpc v1.3.0
// - protoc             v3.19.4
// source: pb/hello.proto
 
package proto
 
import (
	context "context"
	grpc "google.golang.org/grpc"
	codes "google.golang.org/grpc/codes"
	status "google.golang.org/grpc/status"
)
 
// This is a compile-time assertion to ensure that this generated file
// is compatible with the grpc package it is being compiled against.
// Requires gRPC-Go v1.32.0 or later.
const _ = grpc.SupportPackageIsVersion7
 
const (
	HelloService_SayHello_FullMethodName = "/pb.HelloService/SayHello"
)
 
// HelloServiceClient is the client API for HelloService service.
//
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
type HelloServiceClient interface {
	// SayHello 方法
	SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloResponse, error)
}
 
type helloServiceClient struct {
	cc grpc.ClientConnInterface
}
 
func NewHelloServiceClient(cc grpc.ClientConnInterface) HelloServiceClient {
	return &helloServiceClient{cc}
}
 
func (c *helloServiceClient) SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloResponse, error) {
	out := new(HelloResponse)
	err := c.cc.Invoke(ctx, HelloService_SayHello_FullMethodName, in, out, opts...)
	if err != nil {
		return nil, err
	}
	return out, nil
}
 
// HelloServiceServer is the server API for HelloService service.
// All implementations must embed UnimplementedHelloServiceServer
// for forward compatibility
type HelloServiceServer interface {
	// SayHello 方法
	SayHello(context.Context, *HelloRequest) (*HelloResponse, error)
	mustEmbedUnimplementedHelloServiceServer()
}
 
// UnimplementedHelloServiceServer must be embedded to have forward compatible implementations.
type UnimplementedHelloServiceServer struct {
}
 
func (UnimplementedHelloServiceServer) SayHello(context.Context, *HelloRequest) (*HelloResponse, error) {
	return nil, status.Errorf(codes.Unimplemented, "method SayHello not implemented")
}
func (UnimplementedHelloServiceServer) mustEmbedUnimplementedHelloServiceServer() {}
 
// UnsafeHelloServiceServer may be embedded to opt out of forward compatibility for this service.
// Use of this interface is not recommended, as added methods to HelloServiceServer will
// result in compilation errors.
type UnsafeHelloServiceServer interface {
	mustEmbedUnimplementedHelloServiceServer()
}
 
func RegisterHelloServiceServer(s grpc.ServiceRegistrar, srv HelloServiceServer) {
	s.RegisterService(&HelloService_ServiceDesc, srv)
}
 
func _HelloService_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
	in := new(HelloRequest)
	if err := dec(in); err != nil {
		return nil, err
	}
	if interceptor == nil {
		return srv.(HelloServiceServer).SayHello(ctx, in)
	}
	info := &grpc.UnaryServerInfo{
		Server:     srv,
		FullMethod: HelloService_SayHello_FullMethodName,
	}
	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
		return srv.(HelloServiceServer).SayHello(ctx, req.(*HelloRequest))
	}
	return interceptor(ctx, in, info, handler)
}
 
// HelloService_ServiceDesc is the grpc.ServiceDesc for HelloService service.
// It's only intended for direct use with grpc.RegisterService,
// and not to be introspected or modified (even as a copy)
var HelloService_ServiceDesc = grpc.ServiceDesc{
	ServiceName: "pb.HelloService",
	HandlerType: (*HelloServiceServer)(nil),
	Methods: []grpc.MethodDesc{
		{
			MethodName: "SayHello",
			Handler:    _HelloService_SayHello_Handler,
		},
	},
	Streams:  []grpc.StreamDesc{},
	Metadata: "pb/hello.proto",
}

4.server

此段我们主要是定义 service 的具体业务处理逻辑，启动 grpc server。
server

package main
 
import (
	"context"
	"fmt"
	"log"
	"net
 
	"go-grpc-demo1/proto"
 
	"google.golang.org/grpc"
)
 
func main()  {
	// create tcp lis
	lis, err := net.Listen("tcp", ":8093")
	if err != nil {
		panic(err)
	}
 
	// create grpc server
	server := grpc.NewServer()
	// register user defined service
	log.Printf("Register server service: %+v", HelloService{})
	proto.RegisterHelloServiceServer(server, &HelloService{})
	// run grpc server
	if err = server.Serve(lis); err != nil {
		panic(err)
	}
}
 
// 具体业务处理
type HelloService struct {
	proto.UnimplementedHelloServiceServer
}
 
// 具体业务实现的方法逻辑
func (s *HelloService) SayHello(ctx context.Context, req *proto.HelloRequest) (*proto.HelloResponse, error) {
	log.Printf("Recv from RPC Client call, params: %s", req.Name)
	return &proto.HelloResponse{
		Reply: fmt.Sprintf("hello name: %s", req.Name),
	}, nil
}
 

写好 server 后可以启动服务，等待client的连接、请求。

附上 server 端的创建流程：

5.client

客户端代码很简单，此段代码主要根据 pb.go、grpc.pb.go 创建 client，进行server的 Dial 请求：

package main
 
import (
	"context"
	"fmt"
	"log"
 
	"go-grpc-demo1/proto"
 
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)
 
func main()  {
	// conn server
	conn, err := grpc.Dial("localhost:8093", grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		log.Fatalln(err)
	}
 
	// call .grpc.pb.go -> NewClient(), create client
	client := proto.NewHelloServiceClient(conn)
 
	// call .grpc.pb.go client req method, use .pb.go file pre generate req method
	resp, err := client.SayHello(context.Background(), &proto.HelloRequest{
		Name: "gRPC_hello",
	})
 
	// print response params
	fmt.Printf("response: %+v", resp)
}

附上 client 端的创建流程：

6.测试请求响应

先启动 server, 然后启动 client 向server发起请求：
server

2023/03/20 15:07:19 Register server service: {UnimplementedHelloServiceServer:{}}

client

response: reply:"hello name: gRPC_hello"

server

2023/03/20 15:07:19 Register server service: {UnimplementedHelloServiceServer:{}}
2023/03/20 15:08:05 Recv from RPC Client call, params: gRPC_hello

从我们定义的接口及 server 和 client 的请求响应逻辑，我们向 server 端发送带 name 参数的请求，server 端收到后打印请求参数，并返回 reply 响应，整个流程简单，但不失为go-grpc入门实操的一次尝试，更复杂的业务逻辑，更多服务治理，无非就是加功能，但这些基本流程是一样的，动起手来实践吧。

参考文档：

• grpc-go 服务端使用介绍