实验：实现单主模式的Nginx反向代理的高可用 keepalived+nginx

 

 

 

 

一、前期规则设置
CIP：192.168.80.50 gateway:192.168.10.2
KA1：DIP:192.168.80.100 gateway:192.168.80.2 VIP: 192.168.80.222/24
KA2: RIP:192.168.80.110 gateway:192.168.80.2 VIP: 192.168.80.222/24
RS1: RIP:192.168.80.120 gateway:192.168.80.2
RS2: RIP:192.168.80.130 gateway:192.168.80.2

 

KA服务器安装 yum  install  keepalived  nginx
RS服务器安装 yum  install  apache/nginx

一、 KA两个节点都配置nginx反向代理
http {
    upstream websrvs {
        server 192.168.80.120:80;
        server 192.168.80.130:80;
    }
    server {
        listen 80;
        location /{
            proxy_pass http://websrvs/;
        }
    }
}

二、KA脚本两个，要执行权限
cat /etc/keepalived/check_nginx.sh 
#!/bin/bash
killall -0 nginx &> /dev/null || exit 1

三、KA在两个节点都配置实现nginx反向代理高可用 
 cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
   notification_email {
     348987564@qq.com   
   }
   notification_email_from root@localhost  
   smtp_server 127.0.0.1  
   smtp_connect_timeout 30
   router_id localhost7A
   vrrp_iptables
   #vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
   vrrp_mcast_group4 224.0.100.100
}
vrrp_script chk_nginx {   #检查nginx是否运行，不运行权重就减15.也就是变成了backup.
	script "/etc/keepalived/check_nginx.sh"
	interval 1
    	weight -25
    	fall 3
    	rise 2
    	timeout 2
}
vrrp_instance zzhz  {
    state MASTER
    interface eth0
    virtual_router_id 88 
    priority 88        
    advert_int 2         
    authentication {
        auth_type PASS
        auth_pass centos 
    }
    virtual_ipaddress {
        192.168.80.222/24 dev eth0 label eth0:1
    }

    track_script {  
	chk_nginx
	}
}
脚本路径 
[root@localhost7A ~]# cat /etc/keepalived/check_nginx.sh 
#!/bin/bash
/usr/bin/killall -0 nginx
[root@localhost7A ~]# chmod +x /etc/keepalived/check_nginx.sh


四：另一台设置变化部分
router_id ka1
state BACKUP：
priority 77   要小于MASTER。


五 测试：  ka中的nginx   
19:03:11.680037 IP 192.168.80.100 > 224.100.100.43: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 2s, length 20
19:03:13.681014 IP 192.168.80.100 > 224.100.100.43: VRRPv2, Advertisement, vrid 51, prio 75, authtype simple, intvl 2s, length 20 #nginx关
19:03:13.681889 IP 192.168.80.110 > 224.100.100.43: VRRPv2, Advertisement, vrid 51, prio 85, authtype simple, intvl 2s, length 20
19:04:03.744446 IP 192.168.80.110 > 224.100.100.43: VRRPv2, Advertisement, vrid 51, prio 85, authtype simple, intvl 2s, length 20
19:04:03.745267 IP 192.168.80.100 > 224.100.100.43: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 2s, length 20 #nginx开



[root@localhost7A ~]# tailf /var/log/messages
Aug  4 19:05:42 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1
Aug  4 19:05:43 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1
Aug  4 19:05:43 localhost7A Keepalived_vrrp[63914]: VRRP_Script(chk_nginx) failed
Aug  4 19:05:44 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1
Aug  4 19:05:45 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) Changing effective priority from 95 to 75
Aug  4 19:05:45 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1
Aug  4 19:05:45 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) Received advert with higher priority 85, ours 75  #nginx关
Aug  4 19:05:45 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) Entering BACKUP STATE
Aug  4 19:05:45 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) removing protocol VIPs.
Aug  4 19:05:45 localhost7A avahi-daemon[934]: Withdrawing address record for 192.168.80.222 on eth0.
Aug  4 19:05:46 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1
Aug  4 19:05:47 localhost7A Keepalived_vrrp[63914]: /etc/keepalived/check_nginx.sh  exited with status 1


Aug  4 19:06:23 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) Changing effective priority from 75 to 95       #nginx开
Aug  4 19:06:23 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) forcing a new MASTER election
Aug  4 19:06:23 localhost7A avahi-daemon[934]: Received response from host 192.168.80.1 with invalid source port 49695 on interface 'eth0.0'
Aug  4 19:06:25 localhost7A Keepalived_vrrp[63914]: VRRP_Instance(zzhz) Transition to MASTER STATE