环境：
主：linux-node1 110.0.0.137
备：linux-node2 110.0.0.138
VIP: 110.0.0.120
NGINX安装：
# rpm -ivh http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm
# yum install nginx
1.安装keepalived
<pre><code>
# yum -y install kernel-devel make gcc openssl-devel libnl* popt*
# yum install -y openssl openssl-devel
# tar zxf keepalived-1.2.2.tar.gz
# cd keepalived-1.2.2
# ./configure --prefix=/usr/local/keepalived
# make && make install
# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
/bin/cp
/usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
# chmod +x /etc/init.d/keepalived
# mkdir /etc/keepalived
# /bin/cp /usr/local/sbin/keepalived /usr/sbin/
# ll /usr/sbin/
</code></pre>
2.配置keepalived
2.1.配置主nginx（linux-node1）
[root@linux-node1 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/opt/nginx_pid.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
mcast_src_ip 110.0.0.137
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
110.0.0.120
}
}
2.2.配置从nginx（linux-node2）
[root@linux-node2 keepalived]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
sysadmin@firewall.loc
}
notification_email_from Alexandre.Cassen@firewall.loc
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_http_port {
script "/opt/nginx_pid.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
mcast_src_ip 110.0.0.138
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
110.0.0.120
}
}
3.编写nginx检查脚本（主备都需要）：
#!/bin/bash
A=`ps -C nginx --no-header |wc -l`
if [ $A -eq 0 ];then
/etc/init.d/nginx start
sleep 3
if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
/etc/init.d/keepalived stop
fi
fi
4.启动nginx和keepalived
/etc/init.d/nginx start
/etc/init.d/keepalived start
5.检查虚拟化IP 是否绑定成功
主节点：
可以看到vip 110.0.0.120 已经绑定到主的nginx服务器上了。
6.测试：
停止nginx
# /etc/init.d/nginx stop
发现主的nginx无法停止，因为/opt/nginx_pid.sh 会检查nginx状态，如果nginx停止了，那么这个脚本就会自动启动nginx。如果nginx启动失败，那么会立刻停止keepalived，把vip转移到backup nginx上面
我们把nginx的配置文件设置错误，然后停止nginx，这个主的nginx就无法启动了。
检查主nginx机器ip状态：
检查backup nginx主机状态：
看到VIP已经转移到backup主机上了。