golang之etcd服务注册

服务注册封装：

package lib

import (
	"context"
	"fmt"
	"time"

	"go.etcd.io/etcd/clientv3"
)

type ServiceRegister struct {
	etcdClient *clientv3.Client
	leaseID    clientv3.LeaseID
}

func NewServiceRegister(endpoints []string) (*ServiceRegister, error) {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: 5 * time.Second,
	})
	if err != nil {
		return nil, err
	}
	serviceRegister := &ServiceRegister{
		etcdClient: cli,
	}
	return serviceRegister, nil
}

func (sr *ServiceRegister) Register(serviceName, serviceHost string, servicePort uint, refreshSeconds int64) error {
	//创建租约
	lease, err := sr.etcdClient.Grant(context.Background(), refreshSeconds*3)
	if err != nil {
		return err
	}
	sr.leaseID = lease.ID
	key := fmt.Sprintf("%s/%s:%d", serviceName, serviceHost, servicePort)
	value := fmt.Sprintf("%s:%d", serviceHost, servicePort)
	//设置key,value
	_, err = sr.etcdClient.Put(context.Background(), key, value, clientv3.WithLease(lease.ID))
	if err != nil {
		return err
	}
	//自动续约
	keepaliveChan, err := sr.etcdClient.KeepAlive(context.Background(), lease.ID)
	if err != nil {
		return err
	}
	str := fmt.Sprintf("注册服务完成，服务名称：%s,服务地址：%s,服务端口：%d", serviceName, serviceHost, servicePort)
	fmt.Println(str)
	go func() {
		for ka := range keepaliveChan {
			fmt.Println("续约:", ka.TTL, time.Now())
		}
	}()

	return nil
}

func (sr *ServiceRegister) UnRegister() error {
	if _, err := sr.etcdClient.Revoke(context.Background(), sr.leaseID); err != nil {
		return err
	}
	fmt.Println("服务注销")
	return sr.etcdClient.Close()
}

测试：

package main

import (
	"demo/lib"
	"flag"
	"log"
	"time"
)


func main() {
	var host string
	var port uint
	flag.StringVar(&host, "host", "", "服务ip")
	flag.UintVar(&port, "port", 0, "服务端口")
	flag.Parse()
	cli, err := lib.NewServiceRegister([]string{"127.0.0.1:2379"})
	if err != nil {
		log.Fatal(err)
	}
	err = cli.Register("srv/goods", host, port, 5)
	if err != nil {
		log.Fatal(err)
	}

	<-time.After(20 * time.Second)
	cli.UnRegister()

}

编译，执行：

go build -o register.exe
.\register.exe -host="225.12.6.44" -port="6699"
注册服务完成，服务名称：srv/goods,服务地址：225.12.6.44,服务端口：6699
续约: 15 2022-05-08 13:59:11.1538771 +0800 CST m=+0.025507601
续约: 15 2022-05-08 13:59:16.2294614 +0800 CST m=+5.101091901
续约: 15 2022-05-08 13:59:21.3413826 +0800 CST m=+10.213013101
续约: 15 2022-05-08 13:59:26.4369359 +0800 CST m=+15.308566401
服务注销

关于etcd包引用报错问题，在go.mod中加下面代码：

replace github.com/coreos/bbolt => go.etcd.io/bbolt v1.3.4
replace google.golang.org/grpc => google.golang.org/grpc v1.26.0