ETCD集群安装配置及简单应用 老版本

一、环境准备

• CentOS Linux release 7.3.1611 (Core) 
• etcd-v3.2.6

二、ETCD下载

https://github.com/coreos/etcd/releases/download/v3.2.6/etcd-v3.2.6-linux-amd64.tar.gz

三、ETCD安装配置

1.部署架构

• 192.168.108.128 节点1
• 192.168.108.129 节点2
• 192.168.108.130 节点3

2.解压安装：

1.  
   $ tar -zxvf  etcd-v3.2.6-linux-amd64.tar.gz -C /opt/
2.  
   $ cd /opt
3.  
   $ mv etcd-v3.2.6-linux-amd64  etcd-v3.2.6
4.  
   # 创建etcd配置文件目录
5.  
   $ mkdir /etc/etcd          

3.创建etcd配置文件：

$ vi /etc/etcd/conf.yml

节点1，添加如下内容：

1.  
   name: etcd-1
2.  
   data-dir: /opt/etcd-v3.2.6/data
3.  
   listen-client-urls: http://192.168.108.128:2379,http://127.0.0.1:2379
4.  
   advertise-client-urls: http://192.168.108.128:2379,http://127.0.0.1:2379
5.  
   listen-peer-urls: http://192.168.108.128:2380
6.  
   initial-advertise-peer-urls: http://192.168.108.128:2380
7.  
   initial-cluster: etcd-1=http://192.168.108.128:2380,etcd-2=http://192.168.108.129:2380,etcd-3=http://192.168.108.130:2380
8.  
   initial-cluster-token: etcd-cluster-token
9.  
   initial-cluster-state: new

节点2，添加如下内容：

1.  
   name: etcd-2
2.  
   data-dir: /opt/etcd-v3.2.6/data
3.  
   listen-client-urls: http://192.168.108.129:2379,http://127.0.0.1:2379
4.  
   advertise-client-urls: http://192.168.108.129:2379,http://127.0.0.1:2379
5.  
   listen-peer-urls: http://192.168.108.129:2380
6.  
   initial-advertise-peer-urls: http://192.168.108.129:2380
7.  
   initial-cluster: etcd-1=http://192.168.108.128:2380,etcd-2=http://192.168.108.129:2380,etcd-3=http://192.168.108.130:2380
8.  
   initial-cluster-token: etcd-cluster-token
9.  
   initial-cluster-state: new

节点3，添加如下内容：

1.  
   name: etcd-3
2.  
   data-dir: /opt/etcd-v3.2.6/data
3.  
   listen-client-urls: http://192.168.108.130:2379,http://127.0.0.1:2379
4.  
   advertise-client-urls: http://192.168.108.130:2379,http://127.0.0.1:2379
5.  
   listen-peer-urls: http://192.168.108.130:2380
6.  
   initial-advertise-peer-urls: http://192.168.108.130:2380
7.  
   initial-cluster: etcd-1=http://192.168.108.128:2380,etcd-2=http://192.168.108.129:2380,etcd-3=http://192.168.108.130:2380
8.  
   initial-cluster-token: etcd-cluster-token
9.  
   initial-cluster-state: new

4.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

在文件末尾追加：

export ETCDCTL_API=3

 使文件生效：

$ source /etc/profile

四、ETCD命令

$ cd  /opt/etcd-v3.2.6

1.查看版本信息：

1.  
   $ ./etcdctl version
2.  
    
3.  
   etcdctl version: 3.2.6
4.  
   API version: 3.2

2.启动命令：

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

3.查看集群成员信息：

1.  
   $ ./etcdctl member list
2.  
    
3.  
   2618ce5cd761aa8e: name=etcd-3 peerURLs=http://192.168.108.130:2380 clientURLs=http://127.0.0.1:2379,http://192.168.108.130:2379 isLeader=false
4.  
   9c359d48a2f34938: name=etcd-1 peerURLs=http://192.168.108.128:2380 clientURLs=http://127.0.0.1:2379,http://192.168.108.128:2379 isLeader=false
5.  
   f3c45714407d68f3: name=etcd-2 peerURLs=http://192.168.108.129:2380 clientURLs=http://127.0.0.1:2379,http://192.168.108.129:2379 isLeader=true

4.查看集群状态（Leader节点）：

1.  
   $ ./etcdctl cluster-health
2.  
    
3.  
   member 2618ce5cd761aa8e is healthy: got healthy result from http://127.0.0.1:2379
4.  
   member 9c359d48a2f34938 is healthy: got healthy result from http://127.0.0.1:2379
5.  
   member f3c45714407d68f3 is healthy: got healthy result from http://127.0.0.1:2379
6.  
   cluster is healthy

5.HTTPS加密下使用etcdctl检查集群健康状况:

1.  
   $ etcdctl --ca-file /etc/ssl/etcd/ca.pem --cert-file /etc/ssl/etcd/server1.pem --key-file /etc/ssl/etcd/server1-key.pem member list
2.  
   $ etcdctl --ca-file /etc/ssl/etcd/ca.pem --cert-file /etc/ssl/etcd/server1.pem --key-file /etc/ssl/etcd/server1-key.pem cluster-health

五、ECTD读写操作

基于HTTP协议的API使用起来比较简单，这里主要通过etcdctl和curl两种方式来做简单介绍。

1.下面通过给message key设置Hello值示例：

1.  
   $ ./etcdctl set /message Hello
2.  
    
3.  
   Hello
4.  
    
5.  
   $ curl -X PUT http://127.0.0.1:2379/v2/keys/message -d value="Hello"
6.  
   {"action":"set","node":{"key":"/message","value":"Hello","modifiedIndex":4,"createdIndex":4}}

2.读取message的值：

1.  
   $ ./etcdctl  get /message
2.  
   Hello
3.  
    
4.  
   $ curl http://127.0.0.1:2379/v2/keys/message
5.  
   {"action":"get","node":{"key":"/message","value":"Hello","modifiedIndex":9,"createdIndex":9}}

3.删除message key：

1.  
   $ ./etcdctl  rm  /message
2.  
    
3.  
   $ curl -X DELETE http://127.0.0.1:2379/v2/keys/message
4.  
   {"action":"delete","node":{"key":"/message","modifiedIndex":10,"createdIndex":9},"prevNode":{"key":"/message","value":"Hello","modifiedIndex":9,"createdIndex":9}}

说明：因为是集群，所以message在其中一个节点创建后，在集群中的任何节点都可以查询到。

4.查看所有key-value：

curl -s http://127.0.0.1:2379/v2/keys/?recursive=true

六、配置ETCD为启动服务

1.编辑/usr/lib/systemd/system/etcd.service，添加下面内容：

1.  
   [Unit]
2.  
   Description=Etcd Server
3.  
   After=network.target
4.  
   After=network-online.target
5.  
   Wants=network-online.target
6.  
    
7.  
   [Service]
8.  
   Type=notify
9.  
   WorkingDirectory=/opt/etcd-v3.2.6/
10.  
    # User=etcd
11.  
    ExecStart=/opt/etcd-v3.2.6/etcd --config-file=/etc/etcd/conf.yml
12.  
    Restart=on-failure
13.  
    LimitNOFILE=65536
14.  
     
15.  
    [Install]
16.  
    WantedBy=multi-user.target

2.更新启动：

1.  
   systemctl daemon-reload
2.  
   systemctl enable etcd
3.  
   systemctl start etcd
4.  
   systemctl restart etcd
5.  
    
6.  
   systemctl status etcd.service -l