etcd学习(4)-centos7中部署etcd

• etcd的搭建
  • 前言
  • 单机
  • 集群
    • 创建etcd配置文件
    • 更新etcd系统默认配置
    • 启动
    • 配置ETCD为启动服务
  • 测试下
  • 参考

etcd的搭建

前言

这里记录下如何搭建etcd

单机

在etcd的releases中有安装脚本,安装脚本

这里放一个docker的安装脚本

rm -rf /tmp/etcd-data.tmp && mkdir -p /tmp/etcd-data.tmp && 
  docker rmi quay.io/coreos/etcd:v3.5.0 || true && 
  docker run 
  -p 2379:2379 
  -p 2380:2380 
  --mount type=bind,source=/tmp/etcd-data.tmp,destination=/etcd-data 
  --name etcd-gcr-v3.5.0 
  quay.io/coreos/etcd:v3.5.0 
  /usr/local/bin/etcd 
  --name s1 
  --data-dir /etcd-data 
  --listen-client-urls http://0.0.0.0:2379 
  --advertise-client-urls http://0.0.0.0:2379 
  --listen-peer-urls http://0.0.0.0:2380 
  --initial-advertise-peer-urls http://0.0.0.0:2380 
  --initial-cluster s1=http://0.0.0.0:2380 
  --initial-cluster-token tkn 
  --initial-cluster-state new 
  --log-level info 
  --logger zap 
  --log-outputs stderr

集群

这里准备了三台centos7机器

主机	ip
etcd-1	192.168.56.111
etcd-2	192.168.56.112
etcd-3	192.168.56.113

首先在每台机器中安装etcd,这里写了安装的脚本

$ cat etcd.sh 

ETCD_VER=v3.5.0

# choose either URL
GOOGLE_URL=https://storage.googleapis.com/etcd
GITHUB_URL=https://github.com/etcd-io/etcd/releases/download
DOWNLOAD_URL=${GITHUB_URL}

rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
rm -rf /opt/etcd && mkdir -p /opt/etcd

curl -L ${DOWNLOAD_URL}/${ETCD_VER}/etcd-${ETCD_VER}-linux-amd64.tar.gz -o /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz
tar xzvf /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz -C /opt/etcd --strip-components=1
rm -f /tmp/etcd-${ETCD_VER}-linux-amd64.tar.gz

赋予执行权限

$ chmod +x etcd.sh

在每台机器中都执行下

$ ./etcd.sh
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   636  100   636    0     0   1328      0 --:--:-- --:--:-- --:--:--  1330
100 18.4M  100 18.4M    0     0   717k      0  0:00:26  0:00:26 --:--:--  775k
...

创建etcd配置文件

$ mkdir /etc/etcd
$ vi /etc/etcd/conf.yml

节点1

name: etcd-1
data-dir: /opt/etcd/data
listen-client-urls: http://192.168.56.111:2379,http://127.0.0.1:2379
advertise-client-urls: http://192.168.56.111:2379,http://127.0.0.1:2379
listen-peer-urls: http://192.168.56.111:2380
initial-advertise-peer-urls: http://192.168.56.111:2380
initial-cluster: etcd-1=http://192.168.56.111:2380,etcd-2=http://192.168.56.112:2380,etcd-3=http://192.168.56.113:2380
initial-cluster-token: etcd-cluster-token
initial-cluster-state: new

节点2

name: etcd-2
data-dir: /opt/etcd/data
listen-client-urls: http://192.168.56.112:2379,http://127.0.0.1:2379
advertise-client-urls: http://192.168.56.112:2379,http://127.0.0.1:2379
listen-peer-urls: http://192.168.56.112:2380
initial-advertise-peer-urls: http://192.168.56.112:2380
initial-cluster: etcd-1=http://192.168.56.111:2380,etcd-2=http://192.168.56.112:2380,etcd-3=http://192.168.56.113:2380
initial-cluster-token: etcd-cluster-token
initial-cluster-state: new

节点3

name: etcd-3
data-dir: /opt/etcd/data
listen-client-urls: http://192.168.56.113:2379,http://127.0.0.1:2379
advertise-client-urls: http://192.168.56.113:2379,http://127.0.0.1:2379
listen-peer-urls: http://192.168.56.113:2380
initial-advertise-peer-urls: http://192.168.56.113:2380
initial-cluster: etcd-1=http://192.168.56.111:2380,etcd-2=http://192.168.56.112:2380,etcd-3=http://192.168.56.113:2380
initial-cluster-token: etcd-cluster-token
initial-cluster-state: new

配置项说明：

• --name：etcd集群中的节点名，这里可以随意，可区分且不重复就行

• --listen-peer-urls：监听的用于节点之间通信的url，可监听多个，集群内部将通过这些url进行数据交互(如选举，数据同步等)

• --initial-advertise-peer-urls：建议用于节点之间通信的url，节点间将以该值进行通信

• --listen-client-urls：监听的用于客户端通信的url，同样可以监听多个

• --advertise-client-urls：建议使用的客户端通信 url，该值用于 etcd 代理或 etcd 成员与 etcd 节点通信

• --initial-cluster-token： etcd-cluster-1，节点的 token 值，设置该值后集群将生成唯一 id，并为每个节点也生成唯一 id，当使用相同配置文件再启动一个集群时，只要该 token 值不一样，etcd 集群就不会相互影响

• --initial-cluster：也就是集群中所有的 initial-advertise-peer-urls 的合集

• --initial-cluster-state：new，新建集群的标志

更新etcd系统默认配置

当前使用的是etcd v3版本，系统默认的是v2，通过下面命令修改配置。

$ vi /etc/profile
# 在末尾追加  
export ETCDCTL_API=3
# 然后更新
$ source /etc/profile

启动

$ ./etcd --config-file=/etc/etcd/conf.yml

配置ETCD为启动服务

编辑/usr/lib/systemd/system/etcd.service

$ cat /usr/lib/systemd/system/etcd.service
[Unit]
Description=EtcdServer
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
WorkingDirectory=/opt/etcd/
# User=etcd
ExecStart=/opt/etcd/etcd --config-file=/etc/etcd/conf.yml
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

更新启动：

$ systemctl daemon-reload
$ systemctl enable etcd
$ systemctl start etcd
$ systemctl restart etcd

$ systemctl status etcd.service -l

测试下

复制etcd二进制文件到/usr/local/bin/

$ cp /opt/etcd/etcd* /usr/local/bin/

首先设置ETCD_ENDPOINTS

# export ETCDCTL_API=3
# export ETCD_ENDPOINTS=192.168.56.111:2379,192.168.56.112:2379,192.168.56.113:2379

查看状态

$ etcdctl --endpoints=${ETCD_ENDPOINTS} --write-out=table member list
+------------------+---------+--------+----------------------------+--------------------------------------------------+------------+
|        ID        | STATUS  |  NAME  |         PEER ADDRS         |                   CLIENT ADDRS                   | IS LEARNER |
+------------------+---------+--------+----------------------------+--------------------------------------------------+------------+
|  90d224ceb3098d7 | started | etcd-2 | http://192.168.56.112:2380 | http://127.0.0.1:2379,http://192.168.56.112:2379 |      false |
| 3b23fbb7d9c7cd10 | started | etcd-1 | http://192.168.56.111:2380 | http://127.0.0.1:2379,http://192.168.56.111:2379 |      false |
| 7909c74e3f5ffafa | started | etcd-3 | http://192.168.56.113:2380 | http://127.0.0.1:2379,http://192.168.56.113:2379 |      false |
+------------------+---------+--------+----------------------------+--------------------------------------------------+------------+

$ etcdctl --endpoints=${ETCD_ENDPOINTS} --write-out=table endpoint health
+---------------------+--------+------------+-------+
|      ENDPOINT       | HEALTH |    TOOK    | ERROR |
+---------------------+--------+------------+-------+
| 192.168.56.111:2379 |   true | 6.558088ms |       |
| 192.168.56.113:2379 |   true | 6.543104ms |       |
| 192.168.56.112:2379 |   true | 7.405801ms |       |
+---------------------+--------+------------+-------+

$ etcdctl --endpoints=${ETCD_ENDPOINTS} --write-out=table endpoint status
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|      ENDPOINT       |        ID        | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
| 192.168.56.111:2379 | 3b23fbb7d9c7cd10 |   3.5.0 |   20 kB |      true |      false |         2 |         19 |                 19 |        |
| 192.168.56.112:2379 |  90d224ceb3098d7 |   3.5.0 |   20 kB |     false |      false |         2 |         19 |                 19 |        |
| 192.168.56.113:2379 | 7909c74e3f5ffafa |   3.5.0 |   20 kB |     false |      false |         2 |         19 |                 19 |        |
+---------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+

在etcd-1中watch一个key,然后再etcd-2中对key设置一个值

[root@centos7-1 ~]# etcdctl watch test
PUT
test
xiaoming

[root@centos7-3 ~]# etcdctl put test xiaoming
OK

参考

【ETCD集群安装配置】https://zhuanlan.zhihu.com/p/46477992
【Install】https://etcd.io/docs/v3.5/install/
【彻底搞懂 etcd 系列文章（三）：etcd 集群运维部署】https://developer.aliyun.com/article/765312