LVS#Haproxy+Keepalived high availability

Keepalived + Haproxy + nginx

First, the two nginx servers are configured to publish pages on different websites for easy distinction.
Then Haprox provides load balancing for nginx.
Finally, keepalived provides high availability for Haproxy. The
previous blog has completed the load balancing of Haproxy for nginx. This blog mainly focuses on Keepalived for Haproxy to achieve high Available

Keepalived + Haproxy experimental operation

1、haproxy-master 192.168.138.133

slave安装好haproxy后
[root@haproxy-master ~]# \scp /etc/haproxy/haproxy.cfg 192.168.138.131:/etc/haproxy/haproxy.cfg
[root@haproxy-master ~]# vim /etc/keepalived/keepalived.conf 

! Configuration File for keepalived

global_defs {
    
    
   router_id director1
}
vrrp_instance VI_1 {
    
    
    state MASTER
    interface ens33
    virtual_router_id 80
    priority 100
    advert_int 1
    authentication {
    
    
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    
    
        192.168.138.200/24
    }
}
[root@haproxy-master ~]# systemctl start keepalived
[root@haproxy-master ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:e7:33:2b brd ff:ff:ff:ff:ff:ff
    inet 192.168.138.133/24 brd 192.168.138.255 scope global dynamic ens33
       valid_lft 1244sec preferred_lft 1244sec
    inet 192.168.138.200/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fee7:332b/64 scope link 
       valid_lft forever preferred_lft forever

2、haproxy-slave 192.168.138.131

[root@haproxy-slave ~]# yum -y install haproxy
[root@haproxy-slave ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
    
    
   router_id directory2
}
vrrp_instance VI_1 {
    
    
    state BACKUP
    interface ens33
    nopreempt
    virtual_router_id 80
    priority 50
    advert_int 1
    authentication {
    
    
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    
    
        192.168.138.200/24
    }
}
[root@haproxy-slave ~]# systemctl start keepalived

3. Browser access verification, keepalived headshot verification

Verify that VIP access is normal


Headshot verification

4. Check the health of the scheduler Haproxy

[root@haproxy-master ~]# cat /etc/keepalived/check_haproxy.sh 
#!/bin/bash

curl -I http://localhost &>/dev/null
if [ $? -ne 0 ];then
    systemctl stop keepalived
fi
[root@haproxy-master ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
    
    
   router_id director1
}
vrrp_script check_haproxy {
    
    
   script "/etc/keepalived/check_haproxy.sh"
   interval 5
}
vrrp_instance VI_1 {
    
    
    state MASTER
    interface ens33
    virtual_router_id 80
    priority 100
    advert_int 1
    authentication {
    
    
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    
    
        192.168.138.200/24
    }
    track_script {
    
    
        check_haproxy
    }
}