• 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
  • 4. etcdctl get

    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 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。

    1. #!/bin/bash
    2. ETCD_VER=v3.3.4
    3. ETCD_DIR=etcd-download
    4. DOWNLOAD_URL=https://github.com/coreos/etcd/releases/download
    6. # Download
    7. mkdir ${ETCD_DIR}
    8. cd ${ETCD_DIR}
    9. wget ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-linux-amd64.tar.gz 
    10. tar -xzvf etcd-${ETCD_VER}-linux-amd64.tar.gz
    12. # install
    13. cd etcd-${ETCD_VER}-linux-amd64
    14. cp etcdctl /usr/local/bin/

    2. etcdctl V3

    使用etcdctlv3的版本时，需设置环境变量ETCDCTL_API=3。

    1. export ETCDCTL_API=3
    3. 或者在`/etc/profile`文件中添加环境变量
    4. vi /etc/profile
    5. ...
    6. ETCDCTL_API=3
    7. ...
    8. source /etc/profile

    查看当前etcdctl的版本信息etcdctl version。

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

    更多命令帮助可以查询etcdctl —help。

    1. [root@k8s-dbg-master-1 etcd]# etcdctl --help
    2. NAME:
    3.     etcdctl - A simple command line client for etcd3.
    5. USAGE:
    6.     etcdctl
    8. VERSION:
    9.     3.3.4
    11. API VERSION:
    12.     3.3
    15. COMMANDS:
    16.     get            Gets the key or a range of keys
    17.     put            Puts the given key into the store
    18.     del            Removes the specified key or range of keys [key, range_end)
    19.     txn            Txn processes all the requests in one transaction
    20.     compaction        Compacts the event history in etcd
    21.     alarm disarm        Disarms all alarms
    22.     alarm list        Lists all alarms
    23.     defrag            Defragments the storage of the etcd members with given endpoints
    24.     endpoint health        Checks the healthiness of endpoints specified in `--endpoints` flag
    25.     endpoint status        Prints out the status of endpoints specified in `--endpoints` flag
    26.     endpoint hashkv        Prints the KV history hash for each endpoint in --endpoints
    27.     move-leader        Transfers leadership to another etcd cluster member.
    28.     watch            Watches events stream on keys or prefixes
    29.     version            Prints the version of etcdctl
    30.     lease grant        Creates leases
    31.     lease revoke        Revokes leases
    32.     lease timetolive    Get lease information
    33.     lease list        List all active leases
    34.     lease keep-alive    Keeps leases alive (renew)
    35.     member add        Adds a member into the cluster
    36.     member remove        Removes a member from the cluster
    37.     member update        Updates a member in the cluster
    38.     member list        Lists all members in the cluster
    39.     snapshot save        Stores an etcd node backend snapshot to a given file
    40.     snapshot restore    Restores an etcd member snapshot to an etcd directory
    41.     snapshot status        Gets backend snapshot status of a given file
    42.     make-mirror        Makes a mirror at the destination etcd cluster
    43.     migrate            Migrates keys in a v2 store to a mvcc store
    44.     lock            Acquires a named lock
    45.     elect            Observes and participates in leader election
    46.     auth enable        Enables authentication
    47.     auth disable        Disables authentication
    48.     user add        Adds a new user
    49.     user delete        Deletes a user
    50.     user get        Gets detailed information of a user
    51.     user list        Lists all users
    52.     user passwd        Changes password of user
    53.     user grant-role        Grants a role to a user
    54.     user revoke-role    Revokes a role from a user
    55.     role add        Adds a new role
    56.     role delete        Deletes a role
    57.     role get        Gets detailed information of a role
    58.     role list        Lists all roles
    59.     role grant-permission    Grants a key to a role
    60.     role revoke-permission    Revokes a key from a role
    61.     check perf        Check the performance of the etcd cluster
    62.     help            Help about any command
    64. OPTIONS:
    65.       --cacert=""                verify certificates of TLS-enabled secure servers using this CA bundle
    66.       --cert=""                    identify secure client using this TLS certificate file
    67.       --command-timeout=5s            timeout for short running command (excluding dial timeout)
    68.       --debug[=false]                enable client-side debug logging
    69.       --dial-timeout=2s                dial timeout for client connections
    70.   -d, --discovery-srv=""            domain name to query for SRV records describing cluster endpoints
    71.       --endpoints=[127.0.0.1:2379]        gRPC endpoints
    72.       --hex[=false]                print byte strings as hex encoded strings
    73.       --insecure-discovery[=true]        accept insecure SRV records describing cluster endpoints
    74.       --insecure-skip-tls-verify[=false]    skip server certificate verification
    75.       --insecure-transport[=true]        disable transport security for client connections
    76.       --keepalive-time=2s            keepalive time for client connections
    77.       --keepalive-timeout=6s            keepalive timeout for client connections
    78.       --key=""                    identify secure client using this TLS key file
    79.       --user=""                    username[:password] for authentication (prompt if password is not supplied)
    80.   -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

    1. HOST_1=10.240.0.17
    2. HOST_2=10.240.0.18
    3. HOST_3=10.240.0.19
    4. ENDPOINTS=$HOST_1:2379,$HOST_2:2379,$HOST_3:2379
    6. etcdctl --endpoints=$ENDPOINTS member list

    3.2. 增删改查

    1、增

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

    2、查

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

    基于相同前缀查找

    1. etcdctl --endpoints=$ENDPOINTS put web1 value1
    2. etcdctl --endpoints=$ENDPOINTS put web2 value2
    3. etcdctl --endpoints=$ENDPOINTS put web3 value3
    5. etcdctl --endpoints=$ENDPOINTS get web --prefix

    列出所有的key

    1. etcdctl --endpoints=$ENDPOINTS get / --prefix --keys-only

    3、删**

    1. etcdctl --endpoints=$ENDPOINTS put key myvalue
    2. etcdctl --endpoints=$ENDPOINTS del key
    4. etcdctl --endpoints=$ENDPOINTS put k1 value1
    5. etcdctl --endpoints=$ENDPOINTS put k2 value2
    6. 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。

    1. etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status
    3. +------------------+------------------+---------+---------+-----------+-----------+------------+
    4. |     ENDPOINT     |        ID        | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX |
    5. +------------------+------------------+---------+---------+-----------+-----------+------------+
    6. | 10.240.0.17:2379 | 4917a7ab173fabe7 | 3.0.0   | 45 kB   | true      |         4 |      16726 |
    7. | 10.240.0.18:2379 | 59796ba9cd1bcd72 | 3.0.0   | 45 kB   | false     |         4 |      16726 |
    8. | 10.240.0.19:2379 | 94df724b66343e6c | 3.0.0   | 45 kB   | false     |         4 |      16726 |
    9. +------------------+------------------+---------+---------+-----------+-----------+------------+
    11. etcdctl --endpoints=$ENDPOINTS endpoint health
    13. 10.240.0.17:2379 is healthy: successfully committed proposal: took = 3.345431ms
    14. 10.240.0.19:2379 is healthy: successfully committed proposal: took = 3.767967ms
    15. 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：

    1.     member add            Adds a member into the cluster
    2.     member remove        Removes a member from the cluster
    3.     member update        Updates a member in the cluster
    4.     member list            Lists all members in the cluster

    例如 etcdctl member list列出集群成员的命令。

    1. etcdctl --endpoints=http://172.16.5.4:12379 member list -w table
    3. +-----------------+---------+-------+------------------------+-----------------------------------------------+
    4. |       ID        | STATUS  | NAME  |       PEER ADDRS       |                 CLIENT ADDRS                  |
    5. +-----------------+---------+-------+------------------------+-----------------------------------------------+
    6. | c856d92a82ba66a | started | etcd0 | http://172.16.5.4:2380 | http://172.16.5.4:2379,http://172.16.5.4:4001 |
    7. +-----------------+---------+-------+------------------------+-----------------------------------------------+

    4. etcdctl get

    使用etcdctl {command} --help可以查看具体命令的帮助信息。

    1. # etcdctl get --help
    2. NAME:
    3.     get - Gets the key or a range of keys
    5. USAGE:
    6.     etcdctl get [options] <key> [range_end]
    8. OPTIONS:
    9.       --consistency="l"            Linearizable(l) or Serializable(s)
    10.       --from-key[=false]        Get keys that are greater than or equal to the given key using byte compare
    11.       --keys-only[=false]        Get only the keys
    12.       --limit=0                Maximum number of results
    13.       --order=""            Order of results; ASCEND or DESCEND (ASCEND by default)
    14.       --prefix[=false]            Get keys with matching prefix
    15.       --print-value-only[=false]    Only write values when using the "simple" output format
    16.       --rev=0                Specify the kv revision
    17.       --sort-by=""            Sort target; CREATE, KEY, MODIFY, VALUE, or VERSION
    19. GLOBAL OPTIONS:
    20.       --cacert=""                verify certificates of TLS-enabled secure servers using this CA bundle
    21.       --cert=""                    identify secure client using this TLS certificate file
    22.       --command-timeout=5s            timeout for short running command (excluding dial timeout)
    23.       --debug[=false]                enable client-side debug logging
    24.       --dial-timeout=2s                dial timeout for client connections
    25.       --endpoints=[127.0.0.1:2379]        gRPC endpoints
    26.       --hex[=false]                print byte strings as hex encoded strings
    27.       --insecure-skip-tls-verify[=false]    skip server certificate verification
    28.       --insecure-transport[=true]        disable transport security for client connections
    29.       --key=""                    identify secure client using this TLS key file
    30.       --user=""                    username[:password] for authentication (prompt if password is not supplied)
    31.   -w, --write-out="simple"            set the output format (fields, json, protobuf, simple, table)

    文章参考：

    https://coreos.com/etcd/docs/latest/demo.html