Client Set returns ErrClusterUnavailable but succeed

etcd.go

package main

import (
	"github.com/coreos/etcd/client"
	"golang.org/x/net/context"
	"log"
	"time"
)

var (
	kapi client.KeysAPI
	endpoints = []string{"http://127.0.0.1:2379"}
	retryDelay = time.Second * time.Duration(5)
	key = "/test"
)

func connect() bool {
	// init connection
	cfg := client.Config{
		Endpoints: endpoints,
		Transport: client.DefaultTransport,
		// set timeout per request to fail fast when the target endpoint is unavailable
		HeaderTimeoutPerRequest: time.Second,
	}
	c, err := client.New(cfg)
	if err != nil {
		log.Fatal(err)
	}
	kapi = client.NewKeysAPI(c)
	// TODO: use /health to check node's health as well
	// checks if available
	_, err = kapi.Get(context.Background(), "/", nil)
	if err != nil {
		log.Print(err.Error())
		return false
	} else {
		return true
	}
}

func reconnect() {
	for !connect() {
		log.Print(endpoints)
		log.Print("Reconnect..")
		time.Sleep(retryDelay)
	}
}

func main() {
	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
	connect()
	testEtcd()
}

func testEtcd() {
	_, err := kapi.Get(context.Background(), key, nil)
	if err != nil {
		log.Println(err)
		if client.IsKeyNotFound(err) {
			_, err := kapi.Set(context.Background(), key, "", &client.SetOptions{Dir: true})
			if err != nil {
				log.Println(err)
			}
		}
	} else {
		log.Fatal(err)
	}
	//time.Sleep(retryDelay)
	_, err = kapi.Get(context.Background(), key, nil)
	if err != nil {
		log.Println(err)
		if client.IsKeyNotFound(err) {
			_, err := kapi.Set(context.Background(), key, "", &client.SetOptions{Dir: true})
			if err != nil {
				log.Println(err)
			}
		}
	} else {
		log.Fatal(err)
	}
}