nginx+keepalived（双主）

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