该文命令用于etcd3
查看etcd版本
etcdctl version
etcdctl version: 3.4.15
API version: 3.4
插入数据
etcdctl --endpoints="IP:2379" put key value
查询数据
按key值查询
etcdctl --endpoints="IP:2379" get key
查询所有key
etcdctl --endpoints="IP:2379" --from-key ""
不显示key只显示values
etcdctl --endpoints="IP:2379" get --print-value-only key
按key前缀查找
etcdctl --endpoints="IP:2379" get --prefix key前缀
删除数据
删除key
etcdctl --endpoints="IP:2379" del key
删除key name12时并返回被删除的键值对
etcdctl --endpoints="IP:2379" del --prev-kv key
删除指定前缀的key
etcdctl --endpoints="IP:2379" del --prev-kv --prefix key的前缀
删除所有数据
etcdctl --endpoints="IP:2379" del --prefix ""
更新数据
直接put即可更新
（2）对于 API 3 备份与恢复方法
备份数据：
etcdctl --endpoints localhost:2379 snapshot save snapshot.db
查看快照信息
etcdctl --endpoints localhost:2379 snapshot status snapshot.db --write-out=table
恢复：
etcd 恢复之前配置文件，data目录为/data/etcd/：
cat /etc/etcd/etcd.conf
ETCD_NAME=default
ETCD_DATA_DIR="/data/etcd/default.etcd/"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_ADVERTISE_CLIENT_URLS="http://0.0.0.0:2379"
etcdctl --endpoints localhost:2379 snapshot restore snapshot.db --data-dir=./data/etcd/default.etcd
此时会在/data/etcd/ 下新建立 data目录，因此会改变存储路径，此时需要进行数据目录的修改
mv default.etcd default.etcd_bak
mv /data/etcd/data/etcd/default.etcd /data/etcd/
rm -rf /data/etcd/data
保持配置文件不变，重启etcd服务
恢复后的文件需要修改权限为 etcd:etcd
–name:重新指定一个数据目录，可以不指定，默认为 default.etcd
–data-dir：指定数据目录
建议使用时不指定 name 但指定 data-dir，并将 data-dir 对应于 etcd 服务中配置的 data-dir
etcd 集群都是至少 3 台机器，官方也说明了集群容错为 (N-1)/2，所以备份数据一般都是用不到，但是鉴上次 gitlab 出现的问题，对于备份数据也要非常重视。
注意在每个节点进行恢复，一个是恢复数据，一个是重塑身份
ETCDCTL_API=3 etcdctl snapshot restore /root/snap.db \
--name etcd-1 \
--initial-cluster="etcd-1=https://192.168.179.99:2380,etcd-2=https://192.168.179.100:2380,etcd-3=https://192.168.179.101:2380" \
--initial-cluster-token=etcd-cluster \
--initial-advertise-peer-urls=https://192.168.179.99:2380 \
--data-dir=/var/lib/etcd/default.etcd
--name etcd-1 #需要修改为当前节点名称
--initial-advertise-peer-urls=https://192.168.179.99:2380 #当前节点IP
三台集群分别恢复备份数据
解压数据
tar snap-202011252359.tar.gz
172.18.1.11恢复
ETCDCTL_API=3 etcdctl --name=etcd1 --endpoints="http://172.18.1.11:2379" --initial-cluster-token=etcd-cluster --initial-advertise-peer-urls=http://172.18.1.11:2380 --initial-cluster=etcd1=http://172.18.1.11:2380,etcd2=http://172.18.1.12:2380,etcd3=http://172.18.1.13:2380 --data-dir=/var/lib/etcd/ snapshot restore ./snap-202011252359.db
172.18.1.12恢复
ETCDCTL_API=3 etcdctl --name=etcd2 --endpoints="http://172.18.1.12:2379" --initial-cluster-token=etcd-cluster --initial-advertise-peer-urls=http://172.18.1.12:2380 --initial-cluster=etcd1=http://172.18.1.11:2380,etcd2=http://172.18.1.12:2380,etcd3=http://172.18.1.13:2380 --data-dir=/var/lib/etcd/ snapshot restore ./snap-202011252359.db
172.18.1.13恢复
ETCDCTL_API=3 etcdctl --name=etcd3 --endpoints="http://172.18.1.13:2379" --initial-cluster-token=etcd-cluster --initial-advertise-peer-urls=http://172.18.1.13:2380 --initial-cluster=etcd1=http://172.18.1.11:2380,etcd2=http://172.18.1.12:2380,etcd3=http://172.18.1.13:2380 --data-dir=/var/lib/etcd/ snapshot restore ./snap-202011252359.db
启动etcd集群
systemctl daemon-reload
systemctl enable etcd
systemctl start etcd
查看数据恢复
ETCDCTL_API=3 etcdctl --endpoints 172.18.1.11:2379,172.18.1.12:2379,172.18.1.13:2379 get / --prefix
（5）etcd 集群检查
ETCDCTL_API=3 etcdctl --endpoints 172.18.1.11:2379,172.18.1.12:2379,172.18.1.13:2379 endpoint status --write-out="table"
+------------------+------------------+---------+---------+-----------+-----------+------------+
| ENDPOINT | ID | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX |
+------------------+------------------+---------+---------+-----------+-----------+------------+
| 172.18.1.11:2379 | a665d104822ee7c9 | 3.3.18 | 25 kB | true | 81 | 25 |
| 172.18.1.12:2379 | f4f9dc017f438b07 | 3.3.18 | 25 kB | false | 81 | 25 |
| 172.18.1.13:2379 | da1a094d31db677c | 3.3.18 | 25 kB | false | 81 | 25 |
+------------------+------------------+---------+---------+-----------+-----------+------------+
ETCDCTL_API=3 etcdctl --endpoints 172.18.1.11:2379,172.18.1.12:2379,172.18.1.13:2379 endpoint health
172.18.1.11:2379 is healthy: successfully committed proposal: took = 2.078969ms
172.18.1.12:2379 is healthy: successfully committed proposal: took = 2.209654ms
172.18.1.13:2379 is healthy: successfully committed proposal: took = 2.469605ms
