使用 keepalived 高可用 nginx

主节点配置：

global_defs {
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_script chk_nginx {
    script "/usr/bin/killall -0 nginx && exit 0 || exit 1"
    interval 1
    weight -10
    fall 2
    rise 1
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 55
    priority 100
    advert_int 1
#   nopreempt
    authentication {
        auth_type PASS
        auth_pass 12345678
    }
    virtual_ipaddress {
        172.20.47.202
    }

    track_script {
        chk_nginx
   }
}

从节点配置：

global_defs {
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_script chk_nginx {
    script "/usr/bin/killall -0 nginx && exit 0 || exit 1"
    interval 1
    weight -10
    fall 2
    rise 1
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 55
    priority 95
    advert_int  1
#   nopreempt
    authentication {
        auth_type PASS
        auth_pass 12345678
    }
    virtual_ipaddress {
        172.20.47.202
    }

    track_script {
        chk_nginx
   }
}

参考：
https://www.keepalived.org/pdf/UserGuide.pdf
https://github.com/acassen/keepalived