etcd作為一個高可用強一致性的服務發現存儲倉庫，在Kubernetes等開源項目中用的很多，這里簡單記錄下安裝和常用命令以及api
安裝
安裝包可以從 https://github.com/etcd-io/etcd/releases 選擇對應的版本和架構，下載后解壓即可，里面有安裝包和相關文檔，安裝和使用其實都可以看這些文檔。
為了方便管理弄成了服務，加了一個etcd.service文件
[Unit] Description=Etcd Server After=network.target After=network-online.target Wants=network-online.target [Service] Type=notify WorkingDirectory=/var/lib/etcd/ EnvironmentFile=-/etc/etcd/etcd.conf User=etcd # set GOMAXPROCS to number of processors ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /usr/bin/etcd --name=\"${ETCD_NAME}\" --data-dir=\"${ETCD_DATA_DIR}\" --listen-client-urls=\"${ETCD_LISTEN_CLIENT_URLS}\" --listen-peer-urls=\"${ETCD_LISTEN_PEER_URLS}\" --advertise-client-urls=\"${ETCD_ADVERTISE_CLIENT_URLS}\" --initial-advertise-peer-urls=\"${ETCD_INITIAL_ADVERTISE_PEER_URLS}\" --initial-cluster=\"${ETCD_INITIAL_CLUSTER}\" --initial-cluster-state=\"${ETCD_INITIAL_CLUSTER_STATE}\"" Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target
etcd.conf配置文件類似下面這樣，每個節點只要修改name和ip就可以，其他的不用動，ETCD_INITIAL_CLUSTER_TOKEN同一各集群值一樣，不同集群不能重復。
## 配置文件每個節點只要修改name和ip地址即可
#[Member]
ETCD_NAME=node1 ETCD_DATA_DIR=/var/lib/etcd/data ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380 ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379 #[cluster] ETCD_INITIAL_ADVERTISE_PEER_URLS=http://192.168.19.136:2380 ETCD_ADVERTISE_CLIENT_URLS=http://192.168.19.136:2379 ETCD_INITIAL_CLUSTER=node1=http://192.168.19.136:2380,node2=http://192.168.19.137:2380,node3=http://192.168.19.138:2380 ETCD_INITIAL_CLUSTER_STATE=new #創建集群的 token，這個值每個集群保持唯一 ETCD_INITIAL_CLUSTER_TOKEN=etcd-1
安裝方式都差不多，放個例子，都差不多，配置文件那部分自己根據實際情況處理就行了。
## 創建用戶和用戶組 groupadd etcd; useradd -c "Etcd user" -g etcd -s /sbin/nologin -r etcd; service firewalld stop; ## 創建安裝文件夾 mkdir -p /usr/bin/etcd3.3.13/; mkdir -p /etc/etcd/; mkdir -p /var/lib/etcd/data; ## 將文件etcd.service、etcd、etcdctl、etcd.conf上傳到/usr/bin/etcd3.3.13/ chmod +x /usr/bin/etcd3.3.13/*; mv /usr/bin/etcd3.3.13/etcd.service /usr/lib/systemd/system/; mv /usr/bin/etcd3.3.13/etcd /usr/bin/; mv /usr/bin/etcd3.3.13/etcdctl /usr/bin/; ## 每個節點配置文件ip地址不一樣 mv /usr/bin/etcd3.3.13/etcd1.conf /etc/etcd/etcd.conf; mv /usr/bin/etcd3.3.13/etcd2.conf /etc/etcd/etcd.conf; mv /usr/bin/etcd3.3.13/etcd3.conf /etc/etcd/etcd.conf; echo 'export ETCDCTL_API=3' >> /etc/profile source /etc/profile chown etcd:etcd -R /var/lib/etcd/data /etc/etcd*; systemctl enable etcd.service; systemctl start etcd.service;
后台命令
etcd命令可以通過etcdctl來執行，具體命令可以查看官方文檔，或者 etcdctl -h 來查看。
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl -h NAME: etcdctl - A simple command line client for etcd3. USAGE: etcdctl VERSION: 3.3.13 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)
上面講全部命令列出來了，下面簡單列幾個測試集群是否可用的命令
查看版本
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl version etcdctl version: 3.3.13 API version: 3.3
查看集群狀態和節點
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl member list 1804fe6aa6e0806f, started, nmgecqud-etcd-iqqn6mxj, http://10.110.30.213:2380, http://10.110.30.213:2379 5dfebcf67955db33, started, nmgecqud-etcd-u1qyxszm, http://10.110.30.210:2380, http://10.110.30.210:2379 745835aca4e59e07, started, nmgecqud-etcd-pufthgqf, http://10.110.30.212:2380, http://10.110.30.212:2379
插入一條數據
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl put foo bar
OK
根據key查詢數據
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl get foo
foo
bar
刪除一條數據
[root@nmgecqud-etcd-pufthgqf ~]# etcdctl del foo1
1
查詢全部的key
[root@wwjaen60-etcd-sefgxiui opt]# etcdctl --prefix --keys-only=true get "" /test/zyh /zyh/fooa foo fooa
也支持通過restAPI來操作，可以測試從集群外訪問是否正常，例如下面幾個
查看版本get：http://10.110.30.183:2379/version
插入一個鍵值對put: http://10.110.30.183:2379/v2/keys/foo?value=bar
查詢一個鍵get: http://10.110.30.179:2379/v2/keys/foo
查看集群的狀態get：http://10.110.30.183:2379/v2/stats/store
查看全部鍵值get：http://10.110.30.183:2379/v2/keys
