etcd.go

package main

import (
	"flag"
	"time"

	"context"

	etcd "github.com/coreos/etcd/clientv3"
	"github.com/golang/glog"
)

func main() {
	ctx := context.Background()
	flag.Parse()

	cli, err := etcd.New(etcd.Config{
		Endpoints:   []string{"localhost:2379"},
		DialTimeout: 5 * time.Second,
	})
	if err != nil {
		glog.Exitf("failed to connect: %v", err)
	}
	defer cli.Close()

	kvc := etcd.NewKV(cli)
	_, err = kvc.Put(ctx, "test::c", "1")
	if err != nil {
		glog.Exitf("failed to put c: %v", err)
	}

	_, err = kvc.Txn(ctx).If(
		etcd.Compare(etcd.Version("test::a"), ">", 0),
	).Then(
		etcd.OpPut("test::b", "1"),
	).Else(
		etcd.OpTxn([]etcd.Cmp{
			etcd.Compare(etcd.Value("test::c"), "=", "1"),
		}, []etcd.Op{
			etcd.OpPut("test::d", "1"),
		}, nil),
	).Commit()
	if err != nil {
		glog.Exitf("failed to execute transaction: %v", err)
	}
}