关于etcd:etcd基本使用

1. 装置

wget 下载地址 https://mirrors.huaweicloud.c…

etcd.config

name: "etcd"
data-dir: "/var/lib/etcd/data"
listen-client-urls: "http://0.0.0.0:2379"
advertise-client-urls: "http://0.0.0.0:2379"

启动

./etcd --config-file=/opt/etcd/etcd.config

2. 根本命令

设置 key

etcdctl put slq1 1

获取 key

etcdctl get slq1 // 获取 key 为 slq1 的 value

etcdctl get slq1 --print-value-only   // 只打印对应的值

etcdctl get slq1 --hex   // 以十六进制显示

etcdctl get slq1 slq5 // 获取肯定范畴的 key 不包含 slq5

etcdctl get --prefix slq  // 获取以 slq 为前缀的 key

etcdctl get --limit=2 --prefix slq  // 限度数量为 2

etcdctl get --from-key s  // 查找大于 s 的所有 key

etcdctl get --prefix --rev=4 slq1 // 获取 slq1 key version 为 4 时候对应的值

删除 key

etcdctl del slq1 // 删除 slq1

etcdctl del slq1 slq5 // 删除 slq1 到 slq5 的 key

etcdctl del --prefix slq // 删除前缀为 slq 的 key

etcdctl del --from-key s // 删除大于 s 的所有 key

监听 key 变动

etcdctl watch slq1 // 监测 slq1
        
etcdctl watch slq1 slq5 // 监测 slq1 到 slq5 的 key
        
etcdctl watch --prefix slq // 监测前缀为 slq 的 key
        
etcdctl watch --from-key s // 监测大于 s 的所有 key

对 key 进行加锁

etcdctl lock slq1


------------------------------------
[root@node3 opt]# etcdctl lock slq1
slq1/694d7afa84f70318
------------------------------------
[root@node3 etcd]# etcdctl lock slq1
产生阻塞

------------------------------------

事务 txn

etcdctl txn -i   //- i 应用交互式 

清理历史版本信息 compact

etcdctl compact 5

[root@prometheus ~]# etcdctl compact 3
compacted revision 3
[root@prometheus ~]# 

lease 和 ttl

[root@prometheus ~]# etcdctl lease grant 100
lease 694d7afa84f70339 granted with TTL(100s)
[root@prometheus ~]# 
[root@prometheus ~]# 
[root@prometheus ~]# etcdctl put --lease=694d7afa84f70339 slqslq slq
OK
[root@prometheus ~]# 
[root@prometheus ~]# etcdctl get slqslq
slqslq
slq
[root@prometheus ~]#

撤销租期
[root@prometheus ~]# etcdctl lease revoke 694d7afa84f70339
lease 694d7afa84f70339 revoked
[root@prometheus ~]# 
[root@prometheus ~]# 
[root@prometheus ~]# etcdctl get slqslq
[root@prometheus ~]#



查看租期无效工夫
[root@prometheus ~]# etcdctl lease timetolive 694d7afa84f70343
lease 694d7afa84f70343 granted with TTL(100s), remaining(66s)

放弃租期无效
etcdctl lease keep-alive 694d7afa84f70339 
[root@prometheus ~]# etcdctl lease keep-alive 694d7afa84f70343
lease 694d7afa84f70343 keepalived with TTL(100)

3.clientv3 操作 api

下载包

go get -u go.etcd.io/etcd/clientv3@v3.3.24

程序

package main


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


func main() {
    client, err := clientv3.New(clientv3.Config{Endpoints:   []string{"http://192.168.56.111:2379"},
        DialTimeout: 2 * time.Second,
    })
    if err != nil {log.Println("create client err:",err)
    }
    defer client.Close()
    keyName := "slq0909"
    ctx, cancel := context.WithTimeout(context.Background(), time.Second)
    _, err = client.Put(ctx, keyName, "xxxxxx")
    cancel()
    if err != nil {log.Printf("put to etcd failed,err:%v \n",err)
        return
    }
    ctx, cancel = context.WithTimeout(context.Background(), time.Second)
    resp,err := client.Get(ctx, keyName)
    cancel()
    if err != nil {log.Println("get keyname err:",err)
    }
    for _,ev := range resp.Kvs {fmt.Printf("%s:%s \n",ev.Key,ev.Value)
    }

}

后果

问题

装置 clientv3 遇到的问题

go: downloading golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985
# github.com/coreos/etcd/clientv3/balancer/picker
..\..\go\pkg\mod\github.com\coreos\etcd@v3.3.25+incompatible\clientv3\balancer\picker\err.go:37:44: undefined: balancer.PickOptions
..\..\go\pkg\mod\github.com\coreos\etcd@v3.3.25+incompatible\clientv3\balancer\picker\roundrobin_balanced.go:55:54: undefined: balancer.PickOptions
# github.com/coreos/etcd/clientv3/balancer/resolver/endpoint
..\..\go\pkg\mod\github.com\coreos\etcd@v3.3.25+incompatible\clientv3\balancer\resolver\endpoint\endpoint.go:114:78: undefined: resolver.BuildOption
..\..\go\pkg\mod\github.com\coreos\etcd@v3.3.25+incompatible\clientv3\balancer\resolver\endpoint\endpoint.go:182:31: undefined: resolver.ResolveNowOption

go.mod

replace google.golang.org/grpc => google.golang.org/grpc v1.26.0