ETCD实战

一、建立集群

1、在每台机器上建立环境变量

TOKEN=token-01
CLUSTER_STATE=new
NAME_1=machine-1
NAME_2=machine-2
NAME_3=machine-3
HOST_1=10.240.0.17
HOST_2=10.240.0.18
HOST_3=10.240.0.19
CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380

2、在每台机器上运行如下命令

# For machine 1
THIS_NAME=${NAME_1}
THIS_IP=${HOST_1}
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}

# For machine 2
THIS_NAME=${NAME_2}
THIS_IP=${HOST_2}
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}

# For machine 3
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}

3、连接测试

export ETCDCTL_API=3
HOST_1=10.240.0.17
HOST_2=10.240.0.18
HOST_3=10.240.0.19
ENDPOINTS=$HOST_1:2379,$HOST_2:2379,$HOST_3:2379

etcdctl --endpoints=$ENDPOINTS member list

etcdctl --endpoints=$ENDPOINTS put foo "Hello World!"

etcdctl --endpoints=$ENDPOINTS get foo
etcdctl --endpoints=$ENDPOINTS --write-out="json" get foo


===选举

etcdctl --endpoints=$ENDPOINTS elect one p1

# another client with the same name blocks
etcdctl --endpoints=$ENDPOINTS elect one p2

==分布式锁

etcdctl --endpoints=$ENDPOINTS lock mutex1

# another client with the same name blocks
etcdctl --endpoints=$ENDPOINTS lock mutex1


==查看集群状态

etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status

etcdctl --endpoints=$ENDPOINTS endpoint health

==快照

ENDPOINTS=$HOST_1:2379
etcdctl --endpoints=$ENDPOINTS snapshot save my.db


==升级

# write key in etcd version 2 store
export ETCDCTL_API=2
etcdctl --endpoints=http://$ENDPOINT set foo bar

# read key in etcd v2
etcdctl --endpoints=$ENDPOINTS --output="json" get foo

# stop etcd node to migrate, one by one

# migrate v2 data
export ETCDCTL_API=3
etcdctl --endpoints=$ENDPOINT migrate --data-dir="default.etcd" --wal-dir="default.etcd/member/wal"

# restart etcd node after migrate, one by one

# confirm that the key got migrated
etcdctl --endpoints=$ENDPOINTS get /foo