第一次使用etcd为什么这个API这样使用是错误的

func main() { SetLogConfToEtcd() //EtcdExmaple() } func EtcdExmaple() { cli, err := clientv3.New(clientv3.Config{ Endpoints: []string{"localhost:2379", "localhost:22379", "localhost:32379"}, DialTimeout: 5 * time.Second, }) if err != nil { fmt.Println("connect failed, err:", err) return } fmt.Println("connect succ") defer cli.Close() ctx, cancel := context.WithTimeout(context.Background(), time.Second) _, err = cli.Put(ctx, "/logagent/conf/", "sample_value") cancel() if err != nil { fmt.Println("put failed, err:", err) return } ctx, cancel = context.WithTimeout(context.Background(), time.Second) resp, err := cli.Get(ctx, "/logagent/conf/") cancel() if err != nil { fmt.Println("get failed, err:", err) return } for _, ev := range resp.Kvs { fmt.Printf("%s : %s\n", ev.Key, ev.Value) } }