etcd之etcd curl命令(七)-EW帮帮网

1、etcd curl命令

如果需要使用v2 version api，启动etcd时候需要加入ETCD_ENABLE_V2=true参数，否则会报错404 page

not found。

1.1 启动

$ etcd -name etcd-cluster -initial-advertise-peer-urls http://192.168.165.195:2380 \
 -listen-peer-urls http://192.168.165.195:2380 \
 -initial-cluster-token etcd-cluster \
 -advertise-client-urls http://192.168.165.195:2379 \
 -listen-client-urls http://localhost:2379,http://192.168.165.195:2379 \
 -initial-cluster etcd-cluster=http://192.168.165.195:2380 \
 -initial-cluster-state new \
 --enable-v2

1.2 获取etcd信息

版本信息：

$ curl -L http://192.168.165.195:2379/version
{"etcdserver":"3.5.5","etcdcluster":"3.5.0"}

健康状态：

$ curl -L http://192.168.165.195:2379/health
{"health":"true","reason":""}

判断leader和followers：

$ curl -L http://192.168.165.195:2379/v2/stats/leader
{"leader":"7abd6357a5e6e51c","followers":{}}

查看自己的状态：

$ curl -L http://192.168.165.195:2379/v2/stats/self
{"name":"etcd-cluster","id":"7abd6357a5e6e51c","state":"StateLeader","startTime":"2023-02-15T20:15:02.926343872+08:00","leaderInfo":{"leader":"7abd6357a5e6e51c","uptime":"22m21.022576155s","startTime":"2023-02-15T20:15:03.627067903+08:00"},"recvAppendRequestCnt":0,"sendAppendRequestCnt":0}

查看store的状态：

$ curl -L http://192.168.165.195:2379/v2/stats/store
{"getsSuccess":8,"getsFail":16,"setsSuccess":5,"setsFail":0,"deleteSuccess":0,"deleteFail":0,"updateSuccess":0,"updateFail":0,"createSuccess":1,"createFail":0,"compareAndSwapSuccess":0,"compareAndSwapFail":0,"compareAndDeleteSuccess":0,"compareAndDeleteFail":0,"expireCount":1,"watchers":0}

1.3 key操作

1.3.1 新建key

新建key值为message，value为Hello world：

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world"
{"action":"set","node":{"key":"/message","value":"Hello world","modifiedIndex":4,"createdIndex":4}}

修改key和创建key的使用方法相同。

查看key：

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","modifiedIndex":4,"createdIndex":4}}

删除key：

$ curl http://192.168.165.195:2379/v2/keys/message -XDELETE
{"action":"delete","node":{"key":"/message","modifiedIndex":5,"createdIndex":4},"prevNode":{"key":"/message","value":"Hello world","modifiedIndex":4,"createdIndex":4}}

1.3.2 新建带有TTL的key

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world" -d ttl=30
{"action":"set","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:51:00.363776467Z","ttl":30,"modifiedIndex":6,"createdIndex":6}}

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:51:00.363776467Z","ttl":27,"modifiedIndex":6,"createdIndex":6}}
$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:51:00.363776467Z","ttl":23,"modifiedIndex":6,"createdIndex":6}}
$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:51:00.363776467Z","ttl":21,"modifiedIndex":6,"createdIndex":6}}

取消key的TTL：

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world" -d ttl=30
{"action":"set","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:54:00.564015529Z","ttl":30,"modifiedIndex":8,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:54:00.564015529Z","ttl":27,"modifiedIndex":8,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world" -d ttl= -d prevExist=true
{"action":"update","node":{"key":"/message","value":"Hello world","modifiedIndex":9,"createdIndex":8},"prevNode":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:54:00.564015529Z","ttl":20,"modifiedIndex":8,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","modifiedIndex":9,"createdIndex":8}}

重置key的TTL：

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world" -d ttl=30
{"action":"set","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:57:53.70367723Z","ttl":30,"modifiedIndex":10,"createdIndex":10},"prevNode":{"key":"/message","value":"Hello world","modifiedIndex":9,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:57:53.70367723Z","ttl":26,"modifiedIndex":10,"createdIndex":10}}

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d ttl=30 -d refresh=true -d prevExist=true
{"action":"update","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:58:06.464823079Z","ttl":30,"modifiedIndex":11,"createdIndex":10},"prevNode":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:57:53.70367723Z","ttl":18,"modifiedIndex":10,"createdIndex":10}}

$ curl http://192.168.165.195:2379/v2/keys/message
{"action":"get","node":{"key":"/message","value":"Hello world","expiration":"2023-02-15T09:58:06.464823079Z","ttl":28,"modifiedIndex":11,"createdIndex":10}}

1.3.3 新建带有TTL的目录

创建普通目录：

$ curl http://192.168.165.195:2379/v2/keys/dir1 -XPUT -d dir=true
{"action":"set","node":{"key":"/dir1","dir":true,"modifiedIndex":4,"createdIndex":4}}

列出目录下所有的节点信息，最后以/结尾：

$ curl http://192.168.165.195:2379/v2/keys/
{"action":"get","node":{"dir":true,"nodes":[{"key":"/dir1","dir":true,"modifiedIndex":4,"createdIndex":4}]}}

还可以通过 recursive 参数递归列出所有子目录信息：

$ curl http://192.168.165.195:2379/v2/keys?recursive=true
{"action":"get","node":{"dir":true,"nodes":[{"key":"/dir1","dir":true,"modifiedIndex":4,"createdIndex":4}]}}

删除目录，默认情况下只允许删除空目录，如果要删除有内容的目录需要加上recursive=true参数：

$ curl 'http://192.168.165.195:2379/v2/keys/dir1?dir=true' -XDELETE
{"action":"delete","node":{"key":"/dir1","dir":true,"modifiedIndex":5,"createdIndex":4},"prevNode":{"key":"/dir1","dir":true,"modifiedIndex":4,"createdIndex":4}}

创建带超时的目录：

$ curl http://192.168.165.195:2379/v2/keys/dir2 -XPUT -d ttl=30 -d dir=true
{"action":"set","node":{"key":"/dir2","dir":true,"expiration":"2023-02-15T12:15:46.015352979Z","ttl":30,"modifiedIndex":4,"createdIndex":4}}

$ curl 'http://192.168.165.195:2379/v2/keys/dir2?sorted=true'
{"action":"get","node":{"key":"/dir2","dir":true,"expiration":"2023-02-15T12:15:46.015352979Z","ttl":30,"modifiedIndex":4,"createdIndex":4}}

$ curl 'http://192.168.165.195:2379/v2/keys/dir2?sorted=true'
{"action":"get","node":{"key":"/dir2","dir":true,"expiration":"2023-02-15T12:15:46.015352979Z","ttl":27,"modifiedIndex":4,"createdIndex":4}}

向该目录插入数据：

$ curl http://192.168.165.195:2379/v2/keys/dir2/message -XPUT -d value="Hello world"
{"action":"set","node":{"key":"/dir2/message","value":"Hello world","modifiedIndex":5,"createdIndex":5}}

到期之前该目录的数据和普通数据一样，但是该目录到期后数据会被自动删除：

$ curl http://192.168.165.195:2379/v2/keys/dir2/message
{"action":"get","node":{"key":"/dir2/message","value":"Hello world","modifiedIndex":5,"createdIndex":5}}

$ curl http://192.168.165.195:2379/v2/keys/dir2/message
{"errorCode":100,"message":"Key not found","cause":"/dir2","index":6}

1.3.4 自动创建有序的key

注意，下面的/queue为目录，创建方法为POST，不是PUT：

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job1
{"action":"create","node":{"key":"/queue/00000000000000000010","value":"Job1","modifiedIndex":10,"createdIndex":10}}

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job2
{"action":"create","node":{"key":"/queue/00000000000000000011","value":"Job2","modifiedIndex":11,"createdIndex":11}}

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job3
{"action":"create","node":{"key":"/queue/00000000000000000012","value":"Job3","modifiedIndex":12,"createdIndex":12}}

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job4
{"action":"create","node":{"key":"/queue/00000000000000000013","value":"Job4","modifiedIndex":13,"createdIndex":13}}

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job5
{"action":"create","node":{"key":"/queue/00000000000000000014","value":"Job5","modifiedIndex":14,"createdIndex":14}}

$ curl http://192.168.165.195:2379/v2/keys/queue -XPOST -d value=Job6
{"action":"create","node":{"key":"/queue/00000000000000000015","value":"Job6","modifiedIndex":15,"createdIndex":15}}

查看：

$ curl 'http://192.168.165.195:2379/v2/keys/queue?recursive=true&sorted=true'
{"action":"get","node":{"key":"/queue","dir":true,"nodes":[{"key":"/queue/00000000000000000010","value":"Job1","modifiedIndex":10,"createdIndex":10},{"key":"/queue/00000000000000000011","value":"Job2","modifiedIndex":11,"createdIndex":11},{"key":"/queue/00000000000000000012","value":"Job3","modifiedIndex":12,"createdIndex":12},{"key":"/queue/00000000000000000013","value":"Job4","modifiedIndex":13,"createdIndex":13},{"key":"/queue/00000000000000000014","value":"Job5","modifiedIndex":14,"createdIndex":14},{"key":"/queue/00000000000000000015","value":"Job6","modifiedIndex":15,"createdIndex":15}],"modifiedIndex":10,"createdIndex":10}}

1.3.5 创建一个隐藏节点

命名时名字以下划线_开头默认就是隐藏键。

$ curl http://192.168.165.195:2379/v2/keys/_message -XPUT -d value="Hello hidden world"
{"action":"set","node":{"key":"/_message","value":"Hello hidden world","modifiedIndex":7,"createdIndex":7}}

$ curl http://192.168.165.195:2379/v2/keys/_message
{"action":"get","node":{"key":"/_message","value":"Hello hidden world","modifiedIndex":7,"createdIndex":7}}

1.4 一次性watch

开启一个终端：

$ curl http://192.168.165.195:2379/v2/keys/message?wait=true

重新打开二个终端，新建key：

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Hello world"
{"action":"set","node":{"key":"/message","value":"Hello world","modifiedIndex":6,"createdIndex":6}}

此时第一个终端显示如下：

{"action":"set","node":{"key":"/message","value":"Hello world","modifiedIndex":6,"createdIndex":6}}

再次在第一个终端执行watch，在第二个终端更新key：

$ curl http://192.168.165.195:2379/v2/keys/message -XPUT -d value="Nice Day"
{"action":"set","node":{"key":"/message","value":"Nice Day","modifiedIndex":7,"createdIndex":7},"prevNode":{"key":"/message","value":"Hello world","modifiedIndex":6,"createdIndex":6}}

第一个终端显示如下：

{"action":"set","node":{"key":"/message","value":"Nice Day","modifiedIndex":7,"createdIndex":7},"prevNode":{"key":"/message","value":"Hello world","modifiedIndex":6,"createdIndex":6}}

1.5 原子CAS操作（Compare And Swap）

CAS操作的基本用途就是创建分布式的锁服务，即选主，仅当客户端提供的条件等于当前etcd的条件时，才会修改

一个key的值。当前提供的可以比较的条件有：

prevExist：检查key是否存在。如果prevExist为true，则这是一个更新请求，如果prevExist的值是false，这

是一个创建请求
prevValue：检查key之前的value
prevIndex：检查key以前的modifiedIndex

插入一个测试key为foo，值为one：

$ curl http://192.168.165.195:2379/v2/keys/foo -XPUT -d value=one
{"action":"set","node":{"key":"/foo","value":"one","modifiedIndex":8,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/foo
{"action":"get","node":{"key":"/foo","value":"one","modifiedIndex":8,"createdIndex":8}}

插入一个已存在的key并添加参数prevExist=false，因为已经有存在的key：

$ curl http://192.168.165.195:2379/v2/keys/foo?prevExist=false -XPUT -d value=two
{"errorCode":105,"message":"Key already exists","cause":"/foo","index":8}

将插入条件换成prevValue，即检查key的value值，条件相等就替换，否则就提示条件不匹配：

$ curl http://192.168.165.195:2379/v2/keys/foo?prevValue=three -XPUT -d value=two
{"errorCode":101,"message":"Compare failed","cause":"[three != one]","index":8}

$ curl http://192.168.165.195:2379/v2/keys/foo?prevValue=one -XPUT -d value=two
{"action":"compareAndSwap","node":{"key":"/foo","value":"two","modifiedIndex":9,"createdIndex":8},"prevNode":{"key":"/foo","value":"one","modifiedIndex":8,"createdIndex":8}}

$ curl http://192.168.165.195:2379/v2/keys/foo
{"action":"get","node":{"key":"/foo","value":"two","modifiedIndex":9,"createdIndex":8}}

其它操作请参考官网：https://etcd.io/。

etcd之etcd curl命令(七)