HA (High Avaibility) trong Linux với Keepalived

1. Cài đặt keepalived trên 2 máy chủ MTA và Proxy

Chuẩn bị 4 IP Vir bao gồm:
10.58.71.72 proxy1
10.58.71.73 proxy2
10.58.71.74 mta1
10.58.71.75 mta2

Cài đặt keepalived trên 4 máy chủ
# yum --disablerepo=\* --enablerepo=c6-media install gcc kernel-headers kernel-devel keepalived
Sửa file cấu hình luật iptables /etc/sysconfig/iptables
Thêm 2 dòng sau: vào đầu phần luật INPUT
-A INPUT -d 224.0.0.0/8 -j ACCEPT
-A INPUT -p vrrp -j ACCEPT
Sau đó khởi động lại iptables
# service iptables restart
2. Cấu hình keepalived trên máy chủ MTA

Chỉnh sửa file  /etc/keepalived/keepalived.conf (backup lại file cũ trước)

Trên máy chủ MTA1

[root@mta1 ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
 global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server localhost
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script chk_smtp {
       script "</dev/tcp/127.0.0.1/465"
       interval 1
       weight -20
       fall 2
       rise 2
}

    vrrp_script chk_haproxy {        
    script "killall -0 haproxy"   
    interval 2                   
    weight 2                      
    }

vrrp_instance VI_3 {
        interface eth0
        state BACKUP
        virtual_router_id 53
        priority 100
        authentication {
            auth_type PASS
            auth_pass 123456
        }
        virtual_ipaddress {
                10.58.71.74
        }
    track_script {
        chk_smtp
      }
}

vrrp_instance VI_4 {
        interface eth0
        state MASTER
        virtual_router_id 54
        priority 101
        authentication {
            auth_type PASS
            auth_pass 123456a@
        }
        virtual_ipaddress {
        10.58.71.75
        }
    track_script {
        chk_smtp
      }
}

Trên máy chủ mta2 :

[root@mta2 ~]# cat /etc/keepalived/keepalived.conf
/bin/bash: Configuration: command not found
bal_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server localhost
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script chk_smtp {
       script "</dev/tcp/127.0.0.1/465"
       interval 1
       weight -20
       fall 2
       rise 2
}
    vrrp_script chk_haproxy {        
    script "killall -0 haproxy"   
    interval 2                   
    weight 2                      
    }

vrrp_instance VI_3 {
        interface eth0
        state MASTER
        virtual_router_id 53
        priority 101
        authentication {
            auth_type PASS
            auth_pass 123456
        }
        virtual_ipaddress {
                10.58.71.74
        }
    track_script {
        chk_smtp
      }
}

vrrp_instance VI_4 {
        interface eth0
        state BACKUP
        virtual_router_id 54
        priority 100
        authentication {
            auth_type PASS
            auth_pass 123456a@
        }
        virtual_ipaddress {
        10.58.71.75
        }
    track_script {
        chk_smtp
      }
}


3. Cấu hình keepalived trên máy chủ Proxy

[root@proxy1 ~]# cat /etc/keepalived/keepalived.conf

bal_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server localhost
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script chk_pop3 {
       script "</dev/tcp/127.0.0.1/995"
       interval 1
       weight -20
       fall 2
       rise 2
}

vrrp_script chk_imap {
       script "</dev/tcp/127.0.0.1/993"
       interval 1
       weight -20
       fall 2
       rise 2
}

vrrp_script chk_web {
       script "</dev/tcp/127.0.0.1/443"
       interval 1
       weight -20
       fall 2
       rise 2
}

vrrp_script chk_haproxy {        
    script "killall -0 haproxy"   
    interval 2                   
    weight 2                      
    }

vrrp_instance VI_1 {
        interface eth0
        state BACKUP
        virtual_router_id 51
        priority 100
        authentication {
            auth_type PASS
            auth_pass 123456
        }
        virtual_ipaddress {
                10.58.71.72
        }
    track_script {
        chk_pop3
        chk_imap
        chk_web
    }
}

vrrp_instance VI_2 {
        interface eth0
        state MASTER
        virtual_router_id 52
        priority 101
        authentication {
            auth_type PASS
            auth_pass 123456a@
        }
        virtual_ipaddress {
        10.58.71.73
        }
    track_script {
        chk_pop3
        chk_imap
        chk_web
    }
}

Trên máy chủ proxy 2

[root@proxy2 ~]# cat /etc/keepalived/keepalived.conf
/bin/bash: Configuration: command not found
bal_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server localhost
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_script chk_pop3 {
       script "</dev/tcp/127.0.0.1/995"
       interval 1
       weight -20
       fall 2
       rise 2
}

vrrp_script chk_imap {
       script "</dev/tcp/127.0.0.1/993"
       interval 1
       weight -20
       fall 2
       rise 2
}

vrrp_script chk_web {
       script "</dev/tcp/127.0.0.1/443"
       interval 1
       weight -20
       fall 2
       rise 2

}
    vrrp_script chk_haproxy {        
    script "killall -0 haproxy"   
    interval 2                   
    weight 2                      
    }

vrrp_instance VI_1 {
        interface eth0
        state MASTER
        virtual_router_id 51
        priority 101
        authentication {
            auth_type PASS
            auth_pass 123456
        }
        virtual_ipaddress {
                10.58.71.72
        }
    track_script {
        chk_pop3
        chk_imap
        chk_web
    }
}

vrrp_instance VI_2 {
        interface eth0
        state BACKUP
        virtual_router_id 52
        priority 100
        authentication {
            auth_type PASS
            auth_pass 123456a@
        }
        virtual_ipaddress {
        10.58.71.73
        }
    track_script {
        chk_pop3
        chk_imap
        chk_web
    }
}

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