一、环境
nginx1 192.168.40.211
nginx2 192.168.40.132
vip1 192.168.40.223 主为keep1，从为keep2
vip2 192.168.40.222 主为keep2，从为keep1
（此处安装过程皆采用yum方式，不作累述）
二、keepalived配置文件
nginx1
vi /etc/keepalived/keepalived.conf
global_defs {
notification_email {
root@localhost
}
notification_email_from keepalived@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
route_id LVS_DEVEL
}
vrrp_script_chk_nginx {
script "/etc/keepalived/ck_ng.sh"
interval 2
weight 2
}
#VIP1
vrrp_instance VI_1 {
state MASTER
interface ens33
lvs_sync_daemon_interface ens33
virtual_router_id 151
priority 100
advert_int 5
nopreempt
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.40.223
}
track_script {
chk_nginx
}
}
#VIP2
vrrp_instance VI_2 {
state BACKUP
interface ens33
lvs_sync_daemon_interface ens33
virtual_router_id 152
priority 90
advert_int 5
nopreempt
authentication {
auth_type PASS
auth_pass 2222
}
virtual_ipaddress {
192.168.40.222
}
track_script {
chk_nginx
}
}
nginx2
#vi /etc/keepalived/keepalived.conf
global_defs {
notification_email {
root@192.168.40.132
}
notification_email_from keepalived@192.168.40.132
smtp_server 127.0.0.1
smtp_connect_timeout 30
route_id LVS_DEVEL
}
vrrp_script_chk_nginx {
script "/etc/keepalived/ck_ng.sh"
interval 2
weight 2
}
#VIP1
vrrp_instance VI_1 {
state BACKUP
interface ens33
lvs_sync_daemon_interface ens33
virtual_router_id 151
priority 90
advert_int 5
nopreempt
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.40.223
}
track_script {
chk_nginx
}
}
#VIP2
vrrp_instance VI_2 {
state MASTER
interface ens33
lvs_sync_daemon_interface ens33
virtual_router_id 152
priority 100
advert_int 5
nopreempt
authentication {
auth_type PASS
auth_pass 2222
}
virtual_ipaddress {
192.168.40.222
}
track_script {
chk_nginx
}
}
三、nginx检测脚本（两台机子一样）
#vi /etc/keepalived/ck_ng.sh
#!/bin/bash
#检查nginx进程是否存在
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
#尝试启动一次nginx，停止5秒后再次检测
service nginx start
sleep 5
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
#如果启动没成功，就杀掉keepalive触发主备切换
service keepalived stop
fi
fi
#chmod +x /etc/keepalived/ck_ng.sh
四、测试
[root@localhost ~]# ip a （nginx1）
....
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:17:c0:db brd ff:ff:ff:ff:ff:ff
inet 192.168.40.211/24 brd 192.168.40.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.40.223/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe17:c0db/64 scope link
valid_lft forever preferred_lft forever
[root@localhost ~]# ip a (nginx2)
....
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:5e:ba:a3 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.132/24 brd 192.168.40.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.40.222/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe5e:baa3/64 scope link
valid_lft forever preferred_lft forever
停掉nginx1的keepalived，此时nginx1的vip转移到nginx2，如下
[root@localhost ~]# ip a
....
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:5e:ba:a3 brd ff:ff:ff:ff:ff:ff
inet 192.168.40.132/24 brd 192.168.40.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.40.222/32 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.40.223/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::20c:29ff:fe5e:baa3/64 scope link
valid_lft forever preferred_lft forever
两个虚拟IP跑到一台机子上，实验成功