Go语言微服务框架go-micro(入门)

Micro用于构建和管理分布式系统，是一个工具集，其中go-micro框架是对分布式系统的高度抽象，提供分布式系统开发的核心库，可插拔的架构，按需使用

简单示例

编写protobuf文件:

syntax = "proto3";

option go_package = ".;proto";

service Cap {
  rpc SayHello(SayRequest) returns (SayResponse) {}
}

message SayRequest {
  string message = 1;
}

message SayResponse {
  string answer = 1;
}

生成代码:

$ protoc -I ./ --go_out=./proto --micro_out=./proto ./proto/hello.proto

编写服务端:

type CapServer struct{}

func (c *CapServer) SayHello(ctx context.Context, req *proto.SayRequest, resp *proto.SayResponse) error {
	resp.Answer = "hello: " + req.Message
	return nil

}

func main() {
	service := micro.NewService(micro.Name("test.server")) 	// 创建新服务
	service.Init() 	// 初始化方法
	_ = proto.RegisterCapHandler(service.Server(), new(CapServer)) 	// 注册服务
	if err := service.Run(); err != nil {
		fmt.Println(err)
	}
}

客户端:

func main() {
	service := micro.NewService(micro.Name("test.client"))
	service.Init()
	client := proto.NewCapService("test.server", service.Client())
	res, err := client.SayHello(context.TODO(), &proto.SayRequest{Message: "test"})
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(res.Answer)
}

目录搭建

使用docker的micro容器，创建一个micro目录:

$ sudo docker run --rm -v $(pwd):$(pwd) -w $(pwd) micro/micro new user

编写一个用户信息的服务

首先定义一个protobuf文件:

syntax = "proto3";

package go.micro.service.user;
option go_package = ".;proto";

service User {
  rpc Register(UserRegisterRequest) returns (UserRegisterResponse) {}
  rpc Login(UserLoginRequest) returns (UserLoginResponse) {}
  rpc GetUserInfo(UserInfoRequest) returns (UserInfoResponse) {}
}

message UserInfoRequest {
  string user_name = 1;
}

message UserInfoResponse {
  int64 user_id = 1;
  string user_name = 2;
  string first_name = 3;
}

message UserRegisterRequest {
  string user_name = 1;
  string first_name = 2;
  string password = 3;
}

message UserRegisterResponse {
  string message = 1;
}

message UserLoginRequest {
  string user_name = 1;
  string password = 2;
}

message UserLoginResponse {
  bool success = 1;
}

编译该文件:

$ protoc -I ./ --go_out=./ --micro_out=./ user.proto

目录结构:

├── domain
│   ├── model
│   │   └── user.go
│   ├── repository
│   │   └── user_repository.go
│   └── service
│       └── user_data_service.go
├── go.mod
├── go.sum
├── handler
│   └── user.go
├── main.go
├── micro.mu
└── proto
    └── user
        ├── user.pb.go
        ├── user.pb.micro.go
        └── user.proto

核心逻辑

domain/model/user.go

定义用户结构:

package model

type User struct {
	ID           int64  `gorm:"primary_key;not_null;auto_increment"`
	UserName     string `gorm:"unique_index;not_null"`
	FirstName    string
	HashPassword string
}

domain/repository/user_repository.go

这部分代码包括创建数据库，初始化数据库表，增删改查用户信息

package repository

import (
	_ "github.com/go-sql-driver/mysql"
	"github.com/jinzhu/gorm"
	"user/domain/model"
)

type IUserRepository interface {
	InitTable() error // 初始化数据库表
	FindUserByName(string) (*model.User, error)
	FindUserByID(int64) (*model.User, error)
	CreateUser(*model.User) (int64, error)
	DeleteUserByID(int64) error
	UpdateUser(*model.User) error
	FindAll() ([]model.User, error)
}

func NewUserRepository(db *gorm.DB) IUserRepository {
	return &UserRepository{db: db}
}

type UserRepository struct {
	db *gorm.DB
}

func (u *UserRepository) FindAll() ([]model.User, error) {
	userAll := make([]model.User, 0)
	return userAll, u.db.Find(&userAll).Error
}

// InitTable 初始化表
func (u *UserRepository) InitTable() error {
	if u.db.HasTable("users") {
		return nil
	}
	return u.db.CreateTable(&model.User{}).Error
}

func (u *UserRepository) FindUserByName(name string) (*model.User, error) {
	user := &model.User{}
	return user, u.db.Where("username = ?", name).Find(user).Error
}

func (u *UserRepository) FindUserByID(userID int64) (*model.User, error) {
	user := &model.User{}
	return user, u.db.First(user, userID).Error

}

func (u *UserRepository) CreateUser(user *model.User) (int64, error) {
	return user.ID, u.db.Create(user).Error
}

func (u *UserRepository) DeleteUserByID(userID int64) error {
	return u.db.Where("id = ?", userID).Delete(&model.User{}).Error
}

func (u *UserRepository) UpdateUser(user *model.User) error {
	return u.db.Model(user).Update(&user).Error
}

domain/service/user_data_service.go

这部分代码包含业务逻辑，对用户数据进行操作

package service

import (
	"github.com/pkg/errors"
	"golang.org/x/crypto/bcrypt"
	"user/domain/model"
	"user/domain/repository"
)

type IUserDataService interface {
	AddUser(*model.User) (int64, error)
	DeleteUser(int64) error
	UpdateUser(*model.User, bool) error
	FindUserByName(string) (*model.User, error)
	CheckPwd(string, string) (bool, error)
}

func NewUserDataService(userRepository repository.IUserRepository) IUserDataService {
	return &UserDataService{UserRepository: userRepository}
}

func GeneratePassword(userPassword string) ([]byte, error) {
	return bcrypt.GenerateFromPassword([]byte(userPassword), bcrypt.DefaultCost)
}

func ValidatePassword(userPassword string, hashed string) (bool, error) {
	if err := bcrypt.CompareHashAndPassword([]byte(hashed), []byte(userPassword)); err != nil {
		return false, errors.New("wrong password")
	}
	return true, nil
}

type UserDataService struct {
	UserRepository repository.IUserRepository
}

func (u *UserDataService) AddUser(user *model.User) (int64, error) {
	pwdByte, err := GeneratePassword(user.HashPassword)
	if err != nil {
		return user.ID, err
	}
	user.HashPassword = string(pwdByte)
	return u.UserRepository.CreateUser(user)
}

func (u *UserDataService) DeleteUser(userID int64) error {
	return u.UserRepository.DeleteUserByID(userID)
}

func (u *UserDataService) UpdateUser(user *model.User, isChangedPwd bool) error {
	if isChangedPwd {
		pwdByte, err := GeneratePassword(user.HashPassword)
		if err != nil {
			return err
		}
		user.HashPassword = string(pwdByte)
	}
	return u.UserRepository.UpdateUser(user)
}

func (u *UserDataService) FindUserByName(userName string) (*model.User, error) {
	return u.UserRepository.FindUserByName(userName)
}

func (u *UserDataService) CheckPwd(userName string, pwd string) (bool, error) {
	user, err := u.UserRepository.FindUserByName(userName)
	if err != nil {
		return false, err
	}
	return ValidatePassword(pwd, user.HashPassword)
}

程序入口:

package main

import (
	"github.com/jinzhu/gorm"
	"go-micro.dev/v4"
	"log"
	"user/domain/repository"
	srv "user/domain/service"
	"user/handler"
	proto "user/proto/user"
)

func main() {
	service := micro.NewService(
		micro.Name("go.micro.service.user"),
		micro.Version("latest"))
	service.Init()

	db, err := gorm.Open("mysql", "micro:123456@/micro?charset=utf8")
	if err != nil {
		log.Fatalln(err)
	}
	defer db.Close()

	resp := repository.NewUserRepository(db)
	resp.InitTable()
	db.SingularTable(true)

	userDataService := srv.NewUserDataService(repository.NewUserRepository(db))
	err = proto.RegisterUserHandler(service.Server(), &handler.User{UserDataService: userDataService})
	if err != nil {
		log.Fatalln(err)
	}

	if err = service.Run(); err != nil {
		log.Fatalln(err)
	}
}

镜像打包

编写dockerfile打包应用

DockerFile常用命令:

1. FROM: 定制镜像基于FROM的镜像，后续操作都基于该镜像

2. RUN: 用于执行后面跟着的命令行命令

3. COPY，ADD: 复制指令，从文件或者目录到容器里制定路径

4. CMD，ENTRYPOINT: 用于运行程序

5. ENV: 设置环境变量，在后续指令中，就可以使用这个环境变量

6. EXPOSE: 声明端口

7. WORKDIR: 指定工作目录

8. USER: 于指定执行后续命令的用户和用户组

将源程序进行交叉编译为linux平台上的可执行程序:

$ CGO_ENABLE=0 GOOS=linux GOARCH=amd64 go build -o user *.go

编写Dockerfile:

FROM alpine
ADD user /user
ENTRYPOINT ["/user"]

使用以下命令配合Dockerfile即可进行打包:

$ sudo docker build -t user:latest .

使用该命令即可运行:

$ sudo docker run --rm -d user