在go的微服务架构中
使用go-kit组件进行开发微服务
type Reg struct {
Host string
Port int
Client consul.Client
}
func MakeReg (host string , port int) (*Reg , error) {
reg := api.DefaultConfig()
reg.Address = host + ":" + strconv.Itoa(port)
apiclient , err = api.NewClient(reg)
if err != nil {
return nil , err
}
client := consul.NewClient(apiclient)
return &Reg{Host : host , Port : port ,Client : client} , nil
}
func (r Reg) Resiter (servicename , tag , host , seviceid ,checkinter ,healthcheckhttp ,deregisterafter string , port int) bool {
congig := api.AgentServiceRegistration{
Port : port ,
Address : host ,
Name := servicename,
ID := serviceid,
Ckeck : &api.AgentServiceCheck{
Interval : checkinter,
HTTP : "http://" + host + ":" + healthcheckhttp ,
DeregisterCriticalServiceAfter : deregisterafter,
}
}
if err := r.Client.Register(&config) ; err != nil {
fmt.Println(err)
return false
}
return true
}
func (r Reg) Deregister (serviceid string) bool {
dreg := api.AgentServiceRegistration{ID : serviceid}
if err != r.Client.Deregister(&config) ; err != nil {
fmt.Println(err)
return false
}
return true
}
func (r Reg) discover (servicename , tag string ,passingonly bool) ( []*api.ServiceEntry ,error ) {
if entries ,_ ,err := r.Client.Service(servicename , tag , passingonly , nil) ;err != nil {
return nil ,err
}else{
return entries , nil
}
}
补充：go-kit 与 grpc 结合实现注册发现与负载均衡
介绍
grpc提供了简单的负载均衡，需要自己实现服务发现resolve。我们既然要使用go-kit来治理微服务，那么我们就使用go-kit的注册发现、负载均衡机制。
go-kit官方【stringsvc3】例子中使用的负载均衡方案是通过服务端转发进行，翻找下源码go-kit的服务注册发现、负载均衡在【sd】包中。下面我们介绍怎么通过go-kit进行客户端负载均衡。
go-kit提供的注册中心
1、 etcd
2、 consul
3、 eureka
4、 zookeeper
go-kit提供的负载均衡
1、 random[随机]
2、 roundRobin[轮询]
只需实现Balancer接口，我们可以很容易的增加其它负载均衡机制
type Balancer interface {
Endpoint() (endpoint.Endpoint, error)
}
etcd注册发现
etcd和zookeeper类似是一个高可用、强一致性的存储仓库，拥有服务发现功能。 我们就通过go-kit提供的etcd包来实现服务注册发现
服务端代码
服务注册
1、连接注册中心
2、注册当前服务
var (
//etcd服务地址
etcdServer = "127.0.0.1:2379"
//服务的信息目录
prefix = "/services/book/"
//当前启动服务实例的地址
instance = "127.0.0.1:50052"
//服务实例注册的路径
key = prefix + instance
//服务实例注册的val
value = instance
ctx = context.Background()
//服务监听地址
serviceAddress = ":50052"
)
//etcd的连接参数
options := etcdv3.ClientOptions{
DialTimeout: time.Second * 3,
DialKeepAlive: time.Second * 3,
}
//创建etcd连接
client, err := etcdv3.NewClient(ctx, []string{etcdServer}, options)
if err != nil {
panic(err)
}
// 创建注册器
registrar := etcdv3.NewRegistrar(client, etcdv3.Service{
Key: key,
Value: value,
}, log.NewNopLogger())
// 注册器启动注册
registrar.Register()
完整代码
package main
import (
"grpc-test/pb"
"context"
grpc_transport "github.com/go-kit/kit/transport/grpc"
"github.com/go-kit/kit/endpoint"
"google.golang.org/grpc"
"net"
"github.com/go-kit/kit/sd/etcdv3"
"github.com/go-kit/kit/log"
"time"
)
type BookServer struct {
bookListHandler grpc_transport.Handler
bookInfoHandler grpc_transport.Handler
}
//通过grpc调用GetBookInfo时,GetBookInfo只做数据透传, 调用BookServer中对应Handler.ServeGRPC转交给go-kit处理
func (s *BookServer) GetBookInfo(ctx context.Context, in *book.BookInfoParams) (*book.BookInfo, error) {
_, rsp, err := s.bookInfoHandler.ServeGRPC(ctx, in)
if err != nil {
return nil, err
}
return rsp.(*book.BookInfo),err
}
//通过grpc调用GetBookList时,GetBookList只做数据透传, 调用BookServer中对应Handler.ServeGRPC转交给go-kit处理
func (s *BookServer) GetBookList(ctx context.Context, in *book.BookListParams) (*book.BookList, error) {
_, rsp, err := s.bookListHandler.ServeGRPC(ctx, in)
if err != nil {
return nil, err
}
return rsp.(*book.BookList),err
}
//创建bookList的EndPoint
func makeGetBookListEndpoint() endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (interface{}, error) {
//请求列表时返回 书籍列表
bl := new(book.BookList)
bl.BookList = append(bl.BookList, &book.BookInfo{BookId:1,BookName:"21天精通php"})
bl.BookList = append(bl.BookList, &book.BookInfo{BookId:2,BookName:"21天精通java"})
return bl,nil
}
}
//创建bookInfo的EndPoint
func makeGetBookInfoEndpoint() endpoint.Endpoint {
return func(ctx context.Context, request interface{}) (interface{}, error) {
//请求详情时返回 书籍信息
req := request.(*book.BookInfoParams)
b := new(book.BookInfo)
b.BookId = req.BookId
b.BookName = "21天精通php"
return b,nil
}
}
func decodeRequest(_ context.Context, req interface{}) (interface{}, error) {
return req, nil
}
func encodeResponse(_ context.Context, rsp interface{}) (interface{}, error) {
return rsp, nil
}
func main() {
var (
//etcd服务地址
etcdServer = "127.0.0.1:2379"
//服务的信息目录
prefix = "/services/book/"
//当前启动服务实例的地址
instance = "127.0.0.1:50052"
//服务实例注册的路径
key = prefix + instance
//服务实例注册的val
value = instance
ctx = context.Background()
//服务监听地址
serviceAddress = ":50052"
)
//etcd的连接参数
options := etcdv3.ClientOptions{
DialTimeout: time.Second * 3,
DialKeepAlive: time.Second * 3,
}
//创建etcd连接
client, err := etcdv3.NewClient(ctx, []string{etcdServer}, options)
if err != nil {
panic(err)
}
// 创建注册器
registrar := etcdv3.NewRegistrar(client, etcdv3.Service{
Key: key,
Value: value,
}, log.NewNopLogger())
// 注册器启动注册
registrar.Register()
bookServer := new(BookServer)
bookListHandler := grpc_transport.NewServer(
makeGetBookListEndpoint(),
decodeRequest,
encodeResponse,
)
bookServer.bookListHandler = bookListHandler
bookInfoHandler := grpc_transport.NewServer(
makeGetBookInfoEndpoint(),
decodeRequest,
encodeResponse,
)
bookServer.bookInfoHandler = bookInfoHandler
ls, _ := net.Listen("tcp", serviceAddress)
gs := grpc.NewServer(grpc.UnaryInterceptor(grpc_transport.Interceptor))
book.RegisterBookServiceServer(gs, bookServer)
gs.Serve(ls)
}
客户端代码
客户端流程
1、 连接注册中心
2、 获取提供的服务
3、 监听服务目录变化，目录变化更新本地缓存
4、 创建负载均衡器
5、 获取请求的 endPoint
完整代码
package main
import (
"context"
"github.com/go-kit/kit/sd/etcdv3"
"time"
"github.com/go-kit/kit/sd"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/endpoint"
"io"
"github.com/go-kit/kit/sd/lb"
"grpc-test/pb"
"fmt"
"google.golang.org/grpc"
)
func main() {
var (
//注册中心地址
etcdServer = "127.0.0.1:2379"
//监听的服务前缀
prefix = "/services/book/"
ctx = context.Background()
)
options := etcdv3.ClientOptions{
DialTimeout: time.Second * 3,
DialKeepAlive: time.Second * 3,
}
//连接注册中心
client, err := etcdv3.NewClient(ctx, []string{etcdServer}, options)
if err != nil {
panic(err)
}
logger := log.NewNopLogger()
//创建实例管理器, 此管理器会Watch监听etc中prefix的目录变化更新缓存的服务实例数据
instancer, err := etcdv3.NewInstancer(client, prefix, logger)
if err != nil {
panic(err)
}
//创建端点管理器， 此管理器根据Factory和监听的到实例创建endPoint并订阅instancer的变化动态更新Factory创建的endPoint
endpointer := sd.NewEndpointer(instancer, reqFactory, logger)
//创建负载均衡器
balancer := lb.NewRoundRobin(endpointer)
/**
我们可以通过负载均衡器直接获取请求的endPoint，发起请求
reqEndPoint,_ := balancer.Endpoint()
*/
/**
也可以通过retry定义尝试次数进行请求
*/
reqEndPoint := lb.Retry(3, 3*time.Second, balancer)
//现在我们可以通过 endPoint 发起请求了
req := struct{}{}
if _, err = reqEndPoint(ctx, req); err != nil {
panic(err)
}
}
//通过传入的 实例地址 创建对应的请求endPoint
func reqFactory(instanceAddr string) (endpoint.Endpoint, io.Closer, error) {
return func(ctx context.Context, request interface{}) (interface{}, error) {
fmt.Println("请求服务: ", instanceAddr)
conn, err := grpc.Dial(instanceAddr, grpc.WithInsecure())
if err != nil {
fmt.Println(err)
panic("connect error")
}
defer conn.Close()
bookClient := book.NewBookServiceClient(conn)
bi,_:=bookClient.GetBookInfo(context.Background(),&book.BookInfoParams{BookId:1})
fmt.Println("获取书籍详情")
fmt.Println("bookId: 1", " => ", "bookName:", bi.BookName)
bl,_ := bookClient.GetBookList(context.Background(), &book.BookListParams{Page:1, Limit:10})
fmt.Println("获取书籍列表")
for _,b := range bl.BookList {
fmt.Println("bookId:", b.BookId, " => ", "bookName:", b.BookName)
}
return nil,nil
},nil,nil
}
测试
请求测试
请求服务： 127.0.0.1:50052 获取书籍详情 bookId: 1 => bookName: 21天精通php 获取书籍列表 bookId: 1 => bookName: 21天精通php bookId: 2 => bookName: 21天精通java
负载均衡测试
1、 修改server的注册监听端口，启动多个server
instance = "127.0.0.1:50052" serviceAddress = ":50052"
2、client发起多次请求
req := struct{}{}
for i := 1; i <= 8; i++ {
if _, err = reqEndPoint(ctx, req); err != nil {
panic(err)
}
}
通过返回结果中记录的请求地址，我们可以看到已经按照轮询的方式请求不同的微服务实例。
请求服务: 127.0.0.1:50051
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50052
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50051
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50052
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50051
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50052
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50051
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
请求服务: 127.0.0.1:50052
获取书籍详情
bookId: 1 => bookName: 21天精通php
获取书籍列表
bookId: 1 => bookName: 21天精通php
bookId: 2 => bookName: 21天精通java
Process finished with exit code 0
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。如有错误或未考虑完全的地方，望不吝赐教。