golang对etcd存取和数值监测的实现

package main

import (
  "fmt"
  "log"
  "time"

  "go.etcd.io/etcd/clientv3"
  "golang.org/x/net/context"
)

var (
  dialTimeout  = 5 * time.Second
  requestTimeout = 2 * time.Second
  endpoints   = []string{"192.168.99.106:2379", "192.168.99.107:2379", "192.168.99.108:2379"}
)

func main() {
  cli, err := clientv3.New(clientv3.Config{
    Endpoints:  endpoints,
    DialTimeout: dialTimeout,
  })

  if err != nil {
    log.Fatal(err)
  }

  defer cli.Close()

  key1, value1 := "testkey1", "value"

  ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
  _, err = cli.Put(ctx, key1, value1)
  cancel()
  if err != nil {
    log.Println("Put failed. ", err)
  } else {
    log.Printf("Put {%s:%s} succeedn", key1, value1)
  }

  ctx, cancel = context.WithTimeout(context.Background(), requestTimeout)
  resp, err := cli.Get(ctx, key1)
  cancel()
  if err != nil {
    log.Println("Get failed. ", err)
    return
  }

  for _, kv := range resp.Kvs {
    log.Printf("Get {%s:%s} n", kv.Key, kv.Value)
  }

  done := make(chan bool)

  go func() {
    wch := cli.Watch(context.Background(), key1)

    for item := range wch {
      for _, ev := range item.Events {
        log.Printf("Type:%s, key:%s, value:%sn", ev.Type, ev.Kv.Key, ev.Kv.Value)
      }
    }
  }()

  go func() {
    for cnt := 0; cnt < 11; cnt++ {
      value := fmt.Sprintf("%s%d", "value", cnt)
      _, err = cli.Put(context.Background(), key1, value)
      if err != nil {
        log.Println("Put failed. ", err)
      } else {
        log.Printf("Put {%s:%s} succeedn", key1, value)
      }
    }
  }()

  <-done

  log.Println("Done!")
}