etcdctl的使用[v3版本]

Bertha 。 2022-05-25 03:18 203阅读 0赞

*   *  1. etcdctl的安装
     *  2. etcdctl V3
     *  3. etcdctl 常用命令
        
         *  3.1. 指定etcd集群
         *  3.2. 增删改查
         *  3.3. 集群状态
         *  3.4. 集群成员

> `etcdctl`的`v3`版本与`v2`版本使用命令有所不同，本文介绍`etcdctl v3`版本的命令工具的使用方式。

## 1. etcdctl的安装 ##

`etcdctl`的二进制文件可以在 [github.com/coreos/etcd/releases][github.com_coreos_etcd_releases] 选择对应的版本下载，例如可以执行以下`install_etcdctl.sh`的脚本，修改其中的版本信息。

#!/bin/bash
    ETCD_VER=v3.3.4
    ETCD_DIR=etcd-download
    DOWNLOAD_URL=https://github.com/coreos/etcd/releases/download
    
    # Download
    mkdir ${ETCD_DIR}
    cd ${ETCD_DIR}
    wget ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-linux-amd64.tar.gz 
    tar -xzvf etcd-${ETCD_VER}-linux-amd64.tar.gz
    
    # install
    cd etcd-${ETCD_VER}-linux-amd64
    cp etcdctl /usr/local/bin/

## 2. etcdctl V3 ##

使用`etcdctl`v3的版本时，需设置环境变量`ETCDCTL_API=3`。

export ETCDCTL_API=3
    
    或者在`/etc/profile`文件中添加环境变量
    vi /etc/profile
    ...
    ETCDCTL_API=3
    ...
    source /etc/profile

查看当前etcdctl的版本信息`etcdctl version`。

[root@k8s-dbg-master-1 etcd]# etcdctl version
    etcdctl version: 3.3.4
    API version: 3.3

更多命令帮助可以查询`etcdctl —help`。

[root@k8s-dbg-master-1 etcd]# etcdctl --help
    NAME:
        etcdctl - A simple command line client for etcd3.
    
    USAGE:
        etcdctl
    
    VERSION:
        3.3.4
    
    API VERSION:
        3.3
    
    
    COMMANDS:
        get         Gets the key or a range of keys
        put         Puts the given key into the store
        del         Removes the specified key or range of keys [key, range_end)
        txn         Txn processes all the requests in one transaction
        compaction      Compacts the event history in etcd
        alarm disarm        Disarms all alarms
        alarm list      Lists all alarms
        defrag          Defragments the storage of the etcd members with given endpoints
        endpoint health     Checks the healthiness of endpoints specified in `--endpoints` flag
        endpoint status     Prints out the status of endpoints specified in `--endpoints` flag
        endpoint hashkv     Prints the KV history hash for each endpoint in --endpoints
        move-leader     Transfers leadership to another etcd cluster member.
        watch           Watches events stream on keys or prefixes
        version         Prints the version of etcdctl
        lease grant Creates leases lease revoke Revokes leases lease timetolive Get lease information lease list List all active leases lease keep-alive Keeps leases alive (renew) member add Adds a member into the cluster member remove Removes a member from the cluster member update Updates a member in the cluster member list Lists all members in the cluster snapshot save Stores an etcd node backend snapshot to a given file snapshot restore Restores an etcd member snapshot to an etcd directory snapshot status Gets backend snapshot status of a given file make-mirror Makes a mirror at the destination etcd cluster migrate Migrates keys in a v2 store to a mvcc store lock Acquires a named lock elect Observes and participates in leader election auth enable Enables authentication auth disable Disables authentication user add Adds a new user user delete Deletes a user user get Gets detailed information of a user user list Lists all users user passwd Changes password of user user grant-role Grants a role to a user user revoke-role Revokes a role from a user role add Adds a new role role delete Deletes a role role get Gets detailed information of a role role list Lists all roles role grant-permission Grants a key to a role role revoke-permission Revokes a key from a role check perf Check the performance of the etcd cluster help Help about any command OPTIONS: --cacert="" verify certificates of TLS-enabled secure servers using this CA bundle --cert="" identify secure client using this TLS certificate file --command-timeout=5s timeout for short running command (excluding dial timeout) --debug[=false] enable client-side debug logging --dial-timeout=2s dial timeout for client connections -d, --discovery-srv="" domain name to query for SRV records describing cluster endpoints --endpoints=[127.0.0.1:2379] gRPC endpoints --hex[=false] print byte strings as hex encoded strings --insecure-discovery[=true] accept insecure SRV records describing cluster endpoints --insecure-skip-tls-verify[=false] skip server certificate verification --insecure-transport[=true] disable transport security for client connections --keepalive-time=2s keepalive time for client connections --keepalive-timeout=6s keepalive timeout for client connections --key="" identify secure client using this TLS key file --user="" username[:password] for authentication (prompt if password is not supplied) -w, --write-out="simple" set the output format (fields, json, protobuf, simple, table)

## 3. etcdctl 常用命令 ##

### 3.1. 指定etcd集群 ###

HOST_1=10.240.0.17
    HOST_2=10.240.0.18
    HOST_3=10.240.0.19
    ENDPOINTS=$HOST_1:2379,$HOST_2:2379,$HOST_3:2379
    
    etcdctl --endpoints=$ENDPOINTS member list

### 3.2. 增删改查 ###

**1、增**

etcdctl --endpoints=$ENDPOINTS put foo "Hello World!"

**2、查**

etcdctl --endpoints=$ENDPOINTS get foo
    etcdctl --endpoints=$ENDPOINTS --write-out="json" get foo

基于相同前缀查找

etcdctl --endpoints=$ENDPOINTS put web1 value1
    etcdctl --endpoints=$ENDPOINTS put web2 value2
    etcdctl --endpoints=$ENDPOINTS put web3 value3
    
    etcdctl --endpoints=$ENDPOINTS get web --prefix

**3、删**

etcdctl --endpoints=$ENDPOINTS put key myvalue
    etcdctl --endpoints=$ENDPOINTS del key
    
    etcdctl --endpoints=$ENDPOINTS put k1 value1
    etcdctl --endpoints=$ENDPOINTS put k2 value2
    etcdctl --endpoints=$ENDPOINTS del k --prefix

### 3.3. 集群状态 ###

集群状态主要是`etcdctl endpoint status` 和`etcdctl endpoint health`两条命令。

etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status
    
    +------------------+------------------+---------+---------+-----------+-----------+------------+
    | ENDPOINT | ID | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX | +------------------+------------------+---------+---------+-----------+-----------+------------+
    | 10.240.0.17:2379 | 4917a7ab173fabe7 | 3.0.0   | 45 kB   | true      |         4 |      16726 |
    | 10.240.0.18:2379 | 59796ba9cd1bcd72 | 3.0.0   | 45 kB   | false     |         4 |      16726 |
    | 10.240.0.19:2379 | 94df724b66343e6c | 3.0.0 | 45 kB | false | 4 | 16726 | +------------------+------------------+---------+---------+-----------+-----------+------------+
    
    etcdctl --endpoints=$ENDPOINTS endpoint health
    
    10.240.0.17:2379 is healthy: successfully committed proposal: took = 3.345431ms
    10.240.0.19:2379 is healthy: successfully committed proposal: took = 3.767967ms
    10.240.0.18:2379 is healthy: successfully committed proposal: took = 4.025451ms

### 3.4. 集群成员 ###

跟集群成员相关的命令如下：

member add          Adds a member into the cluster
        member remove       Removes a member from the cluster
        member update       Updates a member in the cluster
        member list         Lists all members in the cluster

例如 `etcdctl member list`列出集群成员的命令。

文章参考：

[https://coreos.com/etcd/docs/latest/demo.html][https_coreos.com_etcd_docs_latest_demo.html]

[github.com_coreos_etcd_releases]: https://github.com/coreos/etcd/releases
[https_coreos.com_etcd_docs_latest_demo.html]: https://coreos.com/etcd/docs/latest/demo.html