etcd中kv存储租约和监听（etcd 租约）

etcd中kv存储已经租约和监听的基本使.都说源码之下了无秘密，就不打字了.

package main
import (
 "context"
 "log"
 "time"
 "go.etcd.io/etcd/clientv3"
)
func main() {
 var conf = clientv3.Config{
 Endpoints: []string{"127.0.0.1:2380"},
 DialTimeout: 5 * time.Second,
 }
 //创建clinetv3
 client, err := clientv3.New(conf)
 defer client.Close()
 if err != nil {
 log.Fatal(err.Error())
 }
 //创建租约
 lease := clientv3.NewLease(client)
 //设置租约时间
 leaseResp, err := lease.Grant(context.TODO(), 30)
 if err != nil {
 log.Fatal(err.Error())
 }
 //设置续租
 leaseID := leaseResp.ID
 ctx, _ := context.WithCancel(context.TODO())
 leaseRespChan, err := lease.KeepAlive(ctx, leaseID)
 if err != nil {
 log.Fatal(err.Error()) //设置续租失败 续期之后向leaseRespChan通知
 }
 //监听租约
 go func() {
 for {
 select {
 case resp := <-leaseRespChan:
 if resp == nil {
 log.Println("租约已经到期关闭")
 goto LEASE_OVER
 } else {
 log.Println("续租成功")
 goto END
 }
 }
 LEASE_OVER:
 log.Println("lease 监听结束")
 break
 END:
 time.Sleep(500 * time.Millisecond)
 }
 }()
 //监听某个key的变化
 //ctx1, _ := context.WithTimeout(context.TODO(),20)
 go func() {
 wc := client.Watch(context.TODO(), "/job/v3/1", clientv3.WithPrevKV()) //创建监听
 for v := range wc { //range 监听事件
 for _, e := range v.Events {
 log.Printf("type:%v kv:%v prevKey:%v \n ", e.Type, string(e.Kv.Key), e.PrevKv)
 }
 }
 }()
 //key授权租约
 kv := clientv3.NewKV(client)
 //通过租约put
 putResp, err := kv.Put(context.TODO(), "/job/v3/1", "koock", clientv3.WithLease(leaseID))
 if err != nil {
 log.Printf("put 失败：%s", err.Error())
 }
 log.Printf("%v\n", putResp.Header)
 time.Sleep(10 * time.Second)
 //撤销租约
 _, err = lease.Revoke(context.TODO(), leaseID)
 if err != nil {
 log.Fatalf("撤销租约失败:%s\n", err.Error())
 }
 log.Println("撤销租约成功")
 //cancelFunc()
 //查询key
 getResp, err := kv.Get(context.TODO(), "/job/v3/1")
 if err != nil {
 log.Fatalf("get 失败：%s", err.Error())
 }
 log.Printf("%v", getResp.Kvs)
 time.Sleep(20 * time.Second)
}