keepalived+nginx-1:     192.168.1.23
keepalived+nginx-2:     192.168.1.25

keepalived環境部署：(需要關閉防火牆與selinux)

yum方式部署：

yum install keepalived* -y
#配置檔案:
    /etc/keepalived/keepalived.conf

原始碼方式部署：

#下載版本keepalived-1.4.5版本/安裝配置：
wget https://www.keepalived.org/software/keepalived-1.4.5.tar.gz
tar xf keepalived
 
-1.4.5.tar.gz
cd keepalived-1.4.5
./configure --prefix=/usr/local/keepalived/
make 
make install

 mkdir /etc/keepalived/
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/keepalived/etc/sysconfig/keepalived  /etc/sysconfig/
cp keepalived-1.4.5/keepalived/keepalived.service /etc/systemd/system/
ln 
 
-s /usr/local/keepalived/sbin/keepalived  /usr/sbin/
cp keepalived-1.4.5/keepalived/etc/init.d/keepalived /etc/init.d/
chmod 755 /etc/init.d/keepalived 
systemctl enable keepalived
systemctl start keepalived
ps -ef|gre keepalived

keepalived結合nginx實現高可用：（nginx安裝步驟省略）兩臺keepalived+nginx服務的keepalived配置檔案/nginx程序指令碼 差不多一樣：需要注意的是空格不能多寫 nopreempt不搶佔引數 只對BACKUP生效，對MASTER無效。

! Configuration File for keepalived
global_defs {
  notification_email {
      [email protected]
 }
    notification_email_from wgkgood@163.com
    smtp_server 127.0.0.1
    smtp_connect_timeout 30
}

vrrp_script chk_nginx {
    script  "/data/sh/auto_check_nginx.vip.sh"
    interval 2
    weight 2
}

#VIP1
vrrp_instance VI_1 {
     state  BACKUP
     interface ens33
     virtual_router_id 151
     priority 100
     nopreempt
     advert_int 5
     authentication {
         auth_type  PASS
         auth_pass  1111

     }
     virtual_ipaddress {
         192.168.1.198
     }
     track_script {
        chk_nginx
     }
}

監控nginx服務程序指令碼：
vim /data/sh/auto_check_nginx.vip.sh

NGX_MUX="$(ps -ef|grep nginx|grep -v "grep"|grep -v "check"|wc -l)"
if [ $NGX_MUX -eq 0 ];then
        systemctl stop keepalived
fi

配置keepalived主主模式：

! Configuration File for keepalived
global_defs {
  notification_email {
      [email protected]
 }
    notification_email_from wgkgood@163.com
    smtp_server 127.0.0.1
    smtp_connect_timeout 30
}

vrrp_script chk_nginx {
    script  "/data/sh/auto_check_nginx.vip.sh"
    interval 2
    weight 2
}

#VIP1
vrrp_instance VI_1 {
     state  BACKUP
     interface ens33
     virtual_router_id 151
     priority 90
     nopreempt
     advert_int 5
     authentication {
         auth_type  PASS
         auth_pass  1111

     }
     virtual_ipaddress {
         192.168.1.198
     }
     track_script {
        chk_nginx
     }
}

#VIP2
vrrp_instance VI_2 {
     state  MASTER
     interface ens33
     virtual_router_id 152
     priority 100
     nopreempt
     advert_int 5
     authentication {
         auth_type  PASS
         auth_pass  2222

     }
     virtual_ipaddress {
         192.168.1.199
     }
     track_script {
        chk_nginx
     }
}