etcd第二篇etcdctl详解

Posted 2020-12-30

关于etcd的安装请参考etcd第一篇
本篇主要讲解etcdctl命令使用
查看集群状态
etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status

我们看到node2成为leader
查看集群成员
etcdctl --endpoints=$ENDPOINTS member list

删除成员：
MEMBER_ID=fa6333c794b010d8
etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379
member remove ${MEMBER_ID}
我们看到如下结果

同时node3的etcd已经停止工作
添加成员：
注意：添加已经删除的需要将node3的data.etcd必须删除
这里以添加node3为例
在节点上执行如下命令：
NAME_1=node1
NAME_2=node2
NAME_3=node3
HOST_1=172.16.80.201
HOST_2=172.16.80.202
HOST_3=172.16.80.203
etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379 member add ${NAME_3} --peer-urls=http://${HOST_3}:2380
启动新添加的节点，这里使用--initial-cluster-state existing
NAME_1=node1
NAME_2=node2
NAME_3=node3
HOST_1=172.16.80.201
HOST_2=172.16.80.202
HOST_3=172.16.80.203
TOKEN=token-01
CLUSTER_STATE=existing
CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380
THIS_NAME=${NAME_3}
THIS_IP=${HOST_3}
etcd --data-dir=data.etcd --name ${THIS_NAME}

--initial-advertise-peer-urls http://${THIS_IP}:2380
--listen-peer-urls http://${THIS_IP}:2380
--advertise-client-urls http://${THIS_IP}:2379
--listen-client-urls http://${THIS_IP}:2379
--initial-cluster ${CLUSTER}
--initial-cluster-state ${CLUSTER_STATE}
--initial-cluster-token ${TOKEN}
我们做一个测试，是否主节点写入或删除，其余两个节点也会写入或删除，结果如下（表示正确）
[[email protected] ~]# etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 put foo "a"
OK
[[email protected] ~]# etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 get foo
foo
a

[[email protected] ~]# etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 get foo
foo
a

[[email protected] ~]# etcdctl --endpoints=${HOST_1}:2379,${HOST_2}:2379,${HOST_3}:2379 del foo
1

创建snapshot
etcdctl --endpoints=$ENDPOINTS snapshot save my.db
etcdctl --write-out=table --endpoints=$ENDPOINTS snapshot status my.db

数据迁移：（一般不用，因为etcd是集群，可以添加节点的方式来实现数据迁移，然后删除原有的节点）
etcdctl --endpoints=$ENDPOINT migrate --data-dir="default.etcd" --wal-dir="default.etcd/member/wal"
权限
etcdctl --endpoints=${ENDPOINTS} role add root
etcdctl --endpoints=${ENDPOINTS} role grant-permission root readwrite foo
etcdctl --endpoints=${ENDPOINTS} role get root

etcdctl --endpoints=${ENDPOINTS} user add root
etcdctl --endpoints=${ENDPOINTS} user grant-role root root
etcdctl --endpoints=${ENDPOINTS} user get root

etcdctl --endpoints=${ENDPOINTS} auth enable
#now all client requests go through auth

etcdctl --endpoints=${ENDPOINTS} --user=root:123 put foo bar
etcdctl --endpoints=${ENDPOINTS} get foo
etcdctl --endpoints=${ENDPOINTS} --user=root:123 get foo
etcdctl --endpoints=${ENDPOINTS} --user=root:123 get foo1

参考文章：https://coreos.com/etcd/docs/latest