kubernetes使用etcd做配置中心，要对它加深一些了解。
etcd is a strongly consistent, distributed key-value store that provides a reliable way to store data that needs to be accessed by a distributed system or cluster of machines. It gracefully handles leader elections during network partitions and can tolerate machine failure, even in the leader node.
- 下载etcd docker
发布仓库见：https://github.com/etcd-io/etcd/releases
$ docker pull quay.io/coreos/etcd
- 编辑etcd-compose.yml
推荐养成用compose管理container的习惯
$ cat etcd-compose.yml
version: '3'
services:
etcd-node1:
image: "quay.io/coreos/etcd"
container_name: "etcd-node1"
ports:
- "12379:2379"
- "12380:2380"
command: 'etcd -name etcd-node1 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-node1=http://etcd-node1:2380,etcd-node2=http://etcd-node2:2380,etcd-node3=http://etcd-node3:2380" -initial-cluster-state new'
networks:
- "etcd"
etcd-node2:
image: "quay.io/coreos/etcd"
container_name: "etcd-node2"
ports:
- "22379:2379"
- "22380:2380"
command: 'etcd -name etcd-node2 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-node1=http://etcd-node1:2380,etcd-node2=http://etcd-node2:2380,etcd-node3=http://etcd-node3:2380" -initial-cluster-state new'
networks:
- "etcd"
etcd-node3:
image: "quay.io/coreos/etcd"
container_name: "etcd-node3"
ports:
- "32379:2379"
- "32380:2380"
command: 'etcd -name etcd-node3 -advertise-client-urls http://0.0.0.0:2379 -listen-client-urls http://0.0.0.0:2379 -listen-peer-urls http://0.0.0.0:2380 -initial-cluster-token etcd-cluster -initial-cluster "etcd-node1=http://etcd-node1:2380,etcd-node2=http://etcd-node2:2380,etcd-node3=http://etcd-node3:2380" -initial-cluster-state new'
networks:
- "etcd"
networks:
etcd:
3.启动docker-compose
$ docker-compose -f etcd-compose.yml up -d
4.检查容器状态查询节点成员
$ docker-compose -f etcd-compose.yml ps
Name Command State Ports
------------------------------------------------------------------------------------------------------
etcd-node1 etcd -name etcd-node1 -adv ... Up 0.0.0.0:12379->2379/tcp, 0.0.0.0:12380->2380/tcp
etcd-node2 etcd -name etcd-node2 -adv ... Up 0.0.0.0:22379->2379/tcp, 0.0.0.0:22380->2380/tcp
etcd-node3 etcd -name etcd-node3 -adv ... Up 0.0.0.0:32379->2379/tcp, 0.0.0.0:32380->2380/tcp
# 查询每台的成员，结果是一致的
# curl http://127.0.0.1:12379/v2/members | json_pp
# curl http://127.0.0.1:22379/v2/members | json_pp
# curl http://127.0.0.1:32379/v2/members | json_pp
{
"members" : [
{
"id" : "5b926f852fa1811",
"peerURLs" : [
"http://etcd-node1:2380"
],
"clientURLs" : [
"http://0.0.0.0:2379"
],
"name" : "etcd-node1"
},
{
"peerURLs" : [
"http://etcd-node2:2380"
],
"clientURLs" : [
"http://0.0.0.0:2379"
],
"name" : "etcd-node2",
"id" : "9b3cd975d37c44ce"
},
{
"id" : "9e13ad3ed0f8a26b",
"peerURLs" : [
"http://etcd-node3:2380"
],
"clientURLs" : [
"http://0.0.0.0:2379"
],
"name" : "etcd-node3"
}
]
}
5.销毁测试环境
$ docker-compose -f etcd-compose.yml down
Stopping etcd-node2 ... done
Stopping etcd-node1 ... done
Stopping etcd-node3 ... done
Removing etcd-node2 ... done
Removing etcd-node1 ... done
Removing etcd-node3 ... done
Removing network docker-compose_etcd
