CentOS 7.5安装Keepalived教程

1.环境准备

服务器：CentOS 7.5

2.下载keepalived

下载地址：https://www.keepalived.org/download.html

安装包：keepalived-2.0.10.tar.gz

3.源码安装

>cd /opt
>tar -zxvf keepalived-2.0.10.tar.gz #解压安装包
>cd keepalived-2.0.10 #进入安装目录
>./configure --prefix=/usr/local/keepalived #配置
>make & make install #编译和安装

安装完成后的目录如图所示：

安装包所在路径：/opt/keepalived-2.0.10

4.配置

查看配置文件目录结构：

>tree -l /opt/keepalived-2.0.10/keepalived/etc
keepalived/etc/
├── init
│   ├── keepalived.conf.in
│   ├── Makefile
│   ├── Makefile.am
│   └── Makefile.in
├── init.d
│   ├── keepalived
│   ├── keepalived.rh.init
│   ├── keepalived.suse.init.in
│   ├── Makefile
│   ├── Makefile.am
│   └── Makefile.in
├── keepalived
│   └── keepalived.conf
├── Makefile
├── Makefile.am
├── Makefile.in
├── openrc
│   └── keepalived
└── sysconfig
    └── keepalived

将配置文件拷贝到系统相应目录下：

>mkdir /etc/keepalived
>cd /opt/keepalived-2.0.10/keepalived/etc
>cp ./keepalived/keepalived.conf /etc/keepalived/keepalived.conf
>cp ./init.d/keepalived /etc/init.d/keepalived
>cp ./sysconfig/keepalived /etc/sysconfig/keepalived.conf

设置开机启动：

>chkconfig keepalived on

修改配置文件：

>vim /etc/keepalived/keepalived.conf
global_defs {
   router_id mysql-103 #每台keepalived不一样
}

vrrp_instance VI_1 {
    state MASTER #主实例，BACKUP为从实例
    interface ens160 #网卡名称
    virtual_router_id 51 #主备都相同
    priority 100 #优先级,主备不一样，主高于备
    advert_int 1
    authentication {
        auth_type PASS #主备相同
        auth_pass 1111 #主备相同
    }
    virtual_ipaddress {
        192.168.0.250 #vip,主备相同,且位于同一网段
    }
}

5.防火墙开启VRRP

>firewall-cmd --add-rich-rule='rule protocol value="vrrp" accept' --permanent
>firewall-cmd --reload

6.启动服务

>service keepalived start/stop/restart/status

查看启动状态：

>ps -ef|grep keepalived
root     23512     1  0 11:14 ?        00:00:00 /usr/local/keepalived/sbin/keepalived -D
root     23513 23512  0 11:14 ?        00:00:00 /usr/local/keepalived/sbin/keepalived -D
root     23535  7821  0 11:14 pts/3    00:00:00 grep --color=auto keepalived

验证vip地址：

>ip addr
1: ...(ignore)
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:00... brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.110/24 brd 192.168.0.255 scope global ens160 #本机ip
       valid_lft forever preferred_lft forever
    inet 192.168.0.250/32 scope global ens160 #出现vip
       valid_lft forever preferred_lft forever
    inet6 ffee:eeff.../64 scope link
       valid_lft forever preferred_lft forever

多个keepalived实例在安装完成后须要进行主备交叉验证，关闭主实例，从实例可看到vip，再次启动主实例，此时只有主实例能够看到vip