使用 etcdctl · DOCKER

## 使用 etcdctl `etcdctl` 是一个命令行客户端，它能提供一些简洁的命令，供用户直接跟 `etcd` 服务打交道，而无需基于 `HTTP API` 方式。这在某些情况下将很方便，例如用户对服务进行测试或者手动修改数据库内容。我们也推荐在刚接触 `etcd` 时通过 `etcdctl` 命令来熟悉相关的操作，这些操作跟 `HTTP API` 实际上是对应的。 `etcd` 项目二进制发行包中已经包含了 `etcdctl` 工具，没有的话，可以从 [github.com/coreos/etcd/releases](https://github.com/coreos/etcd/releases) 下载。 `etcdctl` 支持如下的命令，大体上分为数据库操作和非数据库操作两类，后面将分别进行解释。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">NAME:</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> etcdctl - A simple command line client for etcd3.</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">USAGE:</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> etcdctl</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">VERSION:</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> 3.2.10</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">API VERSION:</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> 3.2</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">COMMANDS:</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> get Gets the key or a range of keys</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> put Puts the given key into the store</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> del Removes the specified key or range of keys [key, range_end)</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> txn Txn processes all the requests in one transaction</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> compaction Compacts the event history in etcd</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> alarm disarm Disarms all alarms</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> alarm list Lists all alarms</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> defrag Defragments the storage of the etcd members with given endpoints</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> endpoint health Checks the healthiness of endpoints specified in `--endpoints` flag</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> endpoint status Prints out the status of endpoints specified in `--endpoints` flag</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> watch Watches events stream on keys or prefixes</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> version Prints the version of etcdctl</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> lease grant Creates leases</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> lease revoke Revokes leases</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> lease timetolive Get lease information</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> lease keep-alive Keeps leases alive (renew)</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> member add Adds a member into the cluster</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> member remove Removes a member from the cluster</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> member update Updates a member in the cluster</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> member list Lists all members in the cluster</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> snapshot save Stores an etcd node backend snapshot to a given file</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> snapshot restore Restores an etcd member snapshot to an etcd directory</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> snapshot status Gets backend snapshot status of a given file</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> make-mirror Makes a mirror at the destination etcd cluster</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> migrate Migrates keys in a v2 store to a mvcc store</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> lock Acquires a named lock</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> elect Observes and participates in leader election</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> auth enable Enables authentication</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> auth disable Disables authentication</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> user add Adds a new user</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> user delete Deletes a user</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> user get Gets detailed information of a user</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> user list Lists all users</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> user passwd Changes password of user</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> user grant-role Grants a role to a user</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> user revoke-role Revokes a role from a user</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> role add Adds a new role</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> role delete Deletes a role</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> role get Gets detailed information of a role</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> role list Lists all roles</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> role grant-permission Grants a key to a role</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> role revoke-permission Revokes a key from a role</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> check perf Check the performance of the etcd cluster</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> help Help about any command</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"></code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">OPTIONS:</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --cacert="" verify certificates of TLS-enabled secure servers using this CA bundle</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> --cert="" identify secure client using this TLS certificate file</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --command-timeout=5s timeout for short running command (excluding dial timeout)</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> --debug[=false] enable client-side debug logging</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --dial-timeout=2s dial timeout for client connections</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> --endpoints=[127.0.0.1:2379] gRPC endpoints</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --hex[=false] print byte strings as hex encoded strings</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> --insecure-skip-tls-verify[=false] skip server certificate verification</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --insecure-transport[=true] disable transport security for client connections</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> --key="" identify secure client using this TLS key file</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9"> --user="" username[:password] for authentication (prompt if password is not supplied)</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9"> -w, --write-out="simple" set the output format (fields, json, protobuf, simple, table)</code></li> </ol> ``` ### 数据库操作数据库操作围绕对键值和目录的 CRUD （符合 REST 风格的一套操作：Create）完整生命周期的管理。 etcd 在键的组织上采用了层次化的空间结构（类似于文件系统中目录的概念），用户指定的键可以为单独的名字，如 `testkey`，此时实际上放在根目录 `/` 下面，也可以为指定目录结构，如 `cluster1/node2/testkey`，则将创建相应的目录结构。 > 注：CRUD 即 Create, Read, Update, Delete，是符合 REST 风格的一套 API 操作。 #### put ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl put /testdir/testkey "Hello world"</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">OK</code></li> </ol> ``` #### get 获取指定键的值。例如 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl put testkey hello</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">OK</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl get testkey</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">testkey</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">hello</code></li> </ol> ``` 支持的选项为 `--sort` 对结果进行排序 `--consistent` 将请求发给主节点，保证获取内容的一致性 #### del 删除某个键值。例如 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl del testkey</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">1</code></li> </ol> ``` ### 非数据库操作 #### watch 监测一个键值的变化，一旦键值发生更新，就会输出最新的值。例如，用户更新 `testkey` 键值为 `Hello world`。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl watch testkey</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">PUT</code></li> <li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">testkey</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">2</code></li> </ol> ``` #### member 通过 `list`、`add`、`update`、`remove` 命令列出、添加、更新、删除 etcd 实例到 etcd 集群中。例如本地启动一个 `etcd` 服务实例后，可以用如下命令进行查看。 ``` <pre class="prettyprint"><ol class="linenums"><li class="l"><code class="pcalibre10 pcalibre11 pcalibre9">$ etcdctl member list</code></li> <li class="l1"><code class="pcalibre10 pcalibre11 pcalibre9">422a74f03b622fef, started, node1, http://172.16.238.100:2380, http://172.16.238.100:23</code></li> </ol> ```