go-kit 微服务 服务注册与发现 (etcd 实现 )
etcd
- 相关介绍使用请看文章《Golang etcd 服务发现与负载均衡》 对服务注册，发现，与负载均衡提供了思路
简介
- 通过grpc实现一个用户中心实现简单的鉴权中心并返回用户token
- 上篇文章《go-kit 微服务 使用Grpc（并传递请求ID）》，我们已经实现了一个grpc的服务
- 我们这次主要是添加基于 go-kit 服务注册,发现,负载均衡
服务注册
- 使用go-kit初始化一个etcdV3客户端
options := etcdv3.ClientOptions{
DialTimeout: ttl,
DialKeepAlive: ttl,
}
etcdClient, err := etcdv3.NewClient(context.Background(), etcdAddrs, options)
if err != nil {
utils.GetLogger().Error("[user_agent] NewClient", zap.Error(err))
return
}
Registar := etcdv3.NewRegistrar(etcdClient, etcdv3.Service{
Key: fmt.Sprintf("%s/%s",serName,grpcAddr),
Value: grpcAddr,
}, log.NewNopLogger())
- 将节点注册到服务器
Registar.Register()
- 将节点注销
Registar.Deregister()
服务发现与负载均衡
-
在基于《go-kit 微服务 使用Grpc（并传递请求ID）》 我们已经实现了一个grpc客户端，现在我们只需要为这个客户端添加服务发现，与负载均衡等相关操作
-
创建一个UserAgent结构体，里面包含一个 etcdv3.Instancer 对象和一个 log.Logger对象
type UserAgent struct {
instancerm *etcdv3.Instancer
logger log.Logger
}
-
初始化UserAgent
- 服务发现：通过etcd去查询对应服务的服务地址
func NewUserAgentClient(addr []string, logger log.Logger) (*UserAgent, error) { var ( etcdAddrs = addr serName = "svc.user.agent" ttl = 5 * time.Second ) options := etcdv3.ClientOptions{ DialTimeout: ttl, DialKeepAlive: ttl, } etcdClient, err := etcdv3.NewClient(context.Background(), etcdAddrs, options) if err != nil { return nil, err } instancerm, err := etcdv3.NewInstancer(etcdClient, serName, logger) if err != nil { return nil, err } return &UserAgent{ instancerm: instancerm, logger: logger, }, err
}
+ 负载均衡：把取到的服务地址按照自己需求进行处理（Random，RoundRobin等）
```base
func (u *UserAgent) UserAgentClient() (src.Service, error) {
var (
retryMax = 3
retryTimeout = 500 * time.Millisecond
)
var (
endpoints src.EndPointServer
)
{
factory := u.factoryFor(src.MakeLoginEndPoint)
endpointer := sd.NewEndpointer(u.instancerm, factory, u.logger)
balancer := lb.NewRandom(endpointer, time.Now().UnixNano())
retry := lb.Retry(retryMax, retryTimeout, balancer)
endpoints.LoginEndPoint = retry
}
return endpoints, nil
}
func (u *UserAgent) factoryFor(makeEndpoint func(src.Service) endpoint.Endpoint) sd.Factory {
return func(instance string) (endpoint.Endpoint, io.Closer, error) {
conn, err := grpc.Dial(instance, grpc.WithInsecure())
if err != nil {
return nil, nil, err
}
srv := u.NewGRPCClient(conn)
endpoints := makeEndpoint(srv)
return endpoints, conn, err
}
}
运行日志
- 我们启动3个服务地址分别为（127.0.0.1:8881,127.0.0.1:8882,127.0.0.1:8883）
./user_agent -g 127.0.0.1:8881
2020-01-08 16:28:45 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:45 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8881
./user_agent -g 127.0.0.1:8882
2020-01-08 16:28:45 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:45 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8882
./user_agent -g 127.0.0.1:8883
2020-01-08 16:28:45 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:45 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8883
- 运行 TestNewUserAgentClient 方法 查选3个服务器的日志输入
./user_agent -g 127.0.0.1:8881
2020-01-08 16:28:36 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:36 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8881
2020-01-08 16:30:00 DEBUG src/middleware_server.go:31 [ee92f353-5e8f-526e-b0b4-970d7507e5f6] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjMwLCJpYXQiOjE1Nzg0NzIyMDAsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIwMCwic3ViIjoibG9naW4ifQ.q6lveFqZbgl-10VcaPm4dRrwA4m9FN4i7Fqc82inclY\" ", "time": "272.061µs", "err": null}
2020-01-08 16:30:02 DEBUG src/middleware_server.go:31 [63f4ddb2-dc6b-503a-85aa-bdf99027f91e] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjMyLCJpYXQiOjE1Nzg0NzIyMDIsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIwMiwic3ViIjoibG9naW4ifQ.Td_pBMlkGpK-RjpIOikn1N4BF9q0nID1munt7SvN-0E\" ", "time": "105.5µs", "err": null}
2020-01-08 16:30:03 DEBUG src/middleware_server.go:31 [fe1a7185-cf9b-5bff-91c7-58271f9eecc8] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjMzLCJpYXQiOjE1Nzg0NzIyMDMsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIwMywic3ViIjoibG9naW4ifQ.d7yyFAH70CJvMpK1hIU-rBya0bjwNapP89j_-43liSQ\" ", "time": "40.564µs", "err": null}
2020-01-08 16:30:31 DEBUG src/middleware_server.go:31 [eed06439-bc47-5f17-9329-9fdb3dfbce5f] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjYxLCJpYXQiOjE1Nzg0NzIyMzEsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzMSwic3ViIjoibG9naW4ifQ.jAbaiEPM5QZKY_bHHVb8a_WyflKHKn34l2MPHIarly4\" ", "time": "111.298µs", "err": null}
2020-01-08 16:30:33 DEBUG src/middleware_server.go:31 [21deba8a-2de6-5c44-bd01-633225e652c2] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjYzLCJpYXQiOjE1Nzg0NzIyMzMsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzMywic3ViIjoibG9naW4ifQ.wJWduZ42o99DTUF6Nkhr9h4ddVCiY7G4jZtuhoHIqwE\" ", "time": "59.499µs", "err": null}
2020-01-08 16:30:36 DEBUG src/middleware_server.go:31 [02e304ff-8ef1-5f9a-8ed6-cdd64814ea52] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjY2LCJpYXQiOjE1Nzg0NzIyMzYsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzNiwic3ViIjoibG9naW4ifQ._Rvw4NwSeDrSFIKkzbSVcx0k6YvFVZqGPt3bYFmJUjg\" ", "time": "71.755µs", "err": null}
./user_agent -g 127.0.0.1:8882
2020-01-08 16:28:42 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:42 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8882
2020-01-08 16:30:32 DEBUG src/middleware_server.go:31 [759c5214-ec26-5788-840d-1387f6cce9be] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjYyLCJpYXQiOjE1Nzg0NzIyMzIsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzMiwic3ViIjoibG9naW4ifQ.QQyA9Pt3eDVRBAXc764eIX7MBZYoW8Wr-Tlvw8boyxI\" ", "time": "196.996µs", "err": null}
2020-01-08 16:30:35 DEBUG src/middleware_server.go:31 [ec3826e3-09e6-55f6-9998-baff941a8042] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjY1LCJpYXQiOjE1Nzg0NzIyMzUsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzNSwic3ViIjoibG9naW4ifQ.ZljiQVypRaBrmPgzGK_aKpBbQueJdAPRAKdkzvhi0Yk\" ", "time": "858.642µs", "err": null}
./user_agent -g 127.0.0.1:8883
2020-01-08 16:28:45 INFO logtool/log.go:89 [NewLogger] success
2020-01-08 16:28:45 INFO user_agent/main.go:75 [user_agent] run 127.0.0.1:8883
2020-01-08 16:30:01 DEBUG src/middleware_server.go:31 [e68ec443-5f38-58de-a874-e8ff8ed127c0] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjMxLCJpYXQiOjE1Nzg0NzIyMDEsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIwMSwic3ViIjoibG9naW4ifQ.taUS3LxS8uTAA3loIGEeBfHuYVMgImBBNUnYvgygnVE\" ", "time": "271.665µs", "err": null}
2020-01-08 16:30:34 DEBUG src/middleware_server.go:31 [cabaf11b-4b34-5a4c-98ca-6cc6e31b6da9] {"调用 Login logMiddlewareServer": "Login", "req": "Account:\"hwholiday\" Password:\"123456\" ", "res": "Token:\"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJO1lIjoiaHdob2xpZGF5IiwiRGNJZCI6MSwiZXhwIjoxNTc4NDcyMjY0LCJpYXQiOjE1Nzg0NzIyMzQsImlzcyI6ImtpdF92NCIsIm5iZiI6MTU3ODQ3MjIzNCwic3ViIjoibG9naW4ifQ.yE1Lb51Ov6z-NmJRSrMAMHR1rdReflH5ngslbEttTmo\" ", "time": "114.162µs", "err": null}
结语
- 观察日志看到client请求地址平均分布在3台服务器上，现在已经基本实现了服务注册，发现，负载均衡
- 欢迎添加QQ一起讨论