RedHat 7配置keepalived實現HAproxy羣集

在之前的博文中，我搭建了一個1臺HAproxy+2臺Apache的WEB負載均衡測試環境，然而1臺HAproxy終歸存在單點故障的風險，如果能使用2臺HAproxy做高可用，形成主備羣集，對外提供一個VIP在兩臺HAproxy之間浮動，一旦主的故障，備機立馬接管VIP，保持HAproxy仍舊可用，那就比較完美了，其實很簡單，Keepalived就能實現這樣的功能，且在RedHat 7的安裝光盤中自帶了keepalived的RPM包，通過yum安裝非常方便。通過在兩臺HAproxy上分別安裝Keepalived，形成一主一備，使用VRRP協議檢測心跳信號，VIP可以在兩臺HAproxy之間浮動，實現HAproxy的高可用羣集架構。架構示意圖如下：

關於Apache和HAproxy的安裝配置可以參考本人之前的博文：

《RedHat 7配置HAProxy實現Web負載均衡》

http://jiangjianlong.blog.51cto.com/3735273/1887279

《RedHat 7 安裝配置Apache 2.4》

http://jiangjianlong.blog.51cto.com/3735273/1858650

一、測試環境

計算機名	操作系統	IP地址	VIP	安裝的軟件
RH7-HAproxy01	Redhat 7.2	192.168.10.19	192.168.10.18	Haproxy1.5.14、keepalived 1.2.13
RH7-HAproxy02	Redhat 7.2	192.168.10.20	192.168.10.18	Haproxy1.5.14、keepalived 1.2.13
RH7-Apache01	Redhat 7.2	192.168.10.21	——	Apache httpd 2.4
RH7-Apache02	Redhat 7.2	192.168.10.22	——	Apache httpd 2.4

二、安裝配置keepalived

1、在兩臺HAproxy上分別使用yum install keepalived命令安裝keepalived

[root@RH7-HAproxy01 ~]# yum install keepalived

[root@RH7-HAproxy02 ~]# yum install keepalived

2、編輯RH7-HAproxy01的keepalived配置文件，將其配置成MASTER

[root@RH7-HAproxy01~]# cd /etc/keepalived/

[root@RH7-HAproxy01keepalived]# ls

keepalived.conf

[root@RH7-HAproxy01keepalived]# cp keepalived.conf keepalived.conf.BAK

[root@RH7-HAproxy01keepalived]# ls

keepalived.conf keepalived.conf.BAK

[root@RH7-HAproxy01keepalived]# vi keepalived.conf

! Configuration Filefor keepalived
 
global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
 
#監測haproxy進程狀態，每2秒執行一次
vrrp_scriptchk_haproxy {
    script"/etc/keepalived/chk_haproxy.sh"
    interval 2
    weight 2
    fall 3
}
 
vrrp_instance VI_1 {
    state MASTER  #將HR7-HAproxy01標示爲MASTER
    interface eno50332208 #指定網絡接口
    virtual_router_id 51
    priority 100  #MASTER權重要高於BACKUP
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.18   #VIP
    }
    track_script {
        chk_haproxy #監測haproxy進程狀態
}
}

3、編輯RH7-HAproxy02的keepalived配置文件，將其配置成BACKUP

[root@RH7-HAproxy02 ~]# cd /etc/keepalived/

[root@RH7-HAproxy02 keepalived]# ls

keepalived.conf

[root@RH7-HAproxy02 keepalived]# cp keepalived.confkeepalived.conf.BAK

[root@RH7-HAproxy02 keepalived]# ls

keepalived.conf keepalived.conf.BAK

[root@RH7-HAproxy01keepalived]# vi keepalived.conf

[root@RH7-HAproxy02~]# vi /etc/keepalived/keepalived.conf

global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
 
#監測haproxy進程狀態，每2秒執行一次
vrrp_scriptchk_haproxy {
    script"/etc/keepalived/chk_haproxy.sh"
    interval 2
    weight 2
}
 
 
vrrp_instance VI_1 {
    state BACKUP  #將HR7-HAproxy02標識爲BACKUP
    interface eno50332208 #指定網絡接口
    virtual_router_id 51
    priority 99  #MASTER權重要高於BACKUP
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
 
    virtual_ipaddress {
        192.168.10.18   #VIP
    }
    track_script {
        chk_haproxy #監測haproxy進程狀態
}
}

4、在2臺HAproxy上創建chk_haproxy.sh腳本，內容如下：

vi /etc/keepalived/chk_haproxy.sh

#!/bin/bash
status=$(ps aux|grephaproxy | grep -v grep | grep -v bash | wc -l)
if [ "${status}" = "0" ]; then  #判斷haproxy是否已經啓動
   systemctl start haproxy #如果沒有啓動，則啓動haproxy程序
 
sleep 3  #睡眠3秒鐘以等待haproxy完全啓動
 
status2=$(psaux|grep haproxy | grep -v grep | grep -v bash |wc -l)
    if [ "${status2}" ="0"  ]; then
    systemctl stop keepalived
   #如果haproxy還是沒有啓動，則將keepalived停掉，這樣VIP會自動漂移到另外一臺haproxy
    fi
fi