etcd做注冊服務(wù)使用 類似java生態(tài)的zookeeper，最近在學(xué)學(xué)習(xí)

1、下載etcd包

//直接下載即可（因?yàn)榘容^大有翻墻，可以直接去 https://golangtc.com/download/package 下載）
go get  go.etcd.io/etcd/clientv3

2、使用記錄

packge main

import (
    "context"
    "fmt"
    "go.etcd.io/etcd/clientv3"
    //"log/syslog"
    "time"
)

func main() {
  var (
        config clientv3.Config
        client *clientv3.Client
        err error
        kv clientv3.KV
        putResp *clientv3.PutResponse
        getResp *clientv3.GetResponse
        delResp *clientv3.DeleteResponse
        keepResp *clientv3.LeaseKeepAliveResponse
        keepRespChan <-chan *clientv3.LeaseKeepAliveResponse
    )
}
//客戶端配置
config = clientv3.Config{
    Endpoints:[]string{"127.0.0.1:2379"},
    DialTimeout:5 * time.Second,
}
    //建立連接
if client,err = clientv3.New(config);err != nil {
    fmt.Println(err)
    return
}
//得到操作etcd鍵值對的kv
kv = clientv3.NewKV(client)

//寫入etcd
if putResp,err = kv.Put(context.TODO(),"/cron/jobs/job2","....",clientv3.WithPrevKV()/*可選參數(shù)，得到上次操作的值*/);err != nil {
    fmt.Println(err)
} else {
    fmt.Println(putResp.Header.Revision)

    if putResp.PrevKv != nil {
        fmt.Println(string(putResp.PrevKv.Value))
    }
}
//讀取某個key的value值
getResp,err = kv.Get(context.TODO(),"/cron/jobs/job1"/*,clientv3.WithCountOnly()可選參數(shù)，得到數(shù)量*/)
    if err != nil {
        fmt.Println(err)
        return
    } else {
        fmt.Println(getResp.Kvs[0].Value/*得到的是一個切片*/)
    }
//讀取前綴為XXX的所有的key的value(需要加上參數(shù)clientv3.WithPrefix())
if getResp,err = kv.Get(context.TODO(),"/cron/jobs/",clientv3.WithPrefix());err != nil {
        fmt.Println(err)
        return
    } else {
        fmt.Println(getResp.Kvs)
    }
//刪除操作
if delResp,err = kv.Delete(context.TODO(),"/cron/jobs/job2",clientv3.WithPrevKV()/*得到刪除之前的值*/);err != nil {
        fmt.Println(err)
        return
    } else {
        if len(delResp.PrevKvs) != 0 {
            fmt.Println(delResp.PrevKvs)
        }
    }