[root@localhost ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {                                     #全局定義部分
    notification_email {                          #設(shè)置報(bào)警郵件地址，可設(shè)置多個(gè)
        acassen@firewall.loc                      #接收通知的郵件地址
    }
    notification_email_from test0@163.com         #設(shè)置 發(fā)送郵件通知的地址
    smtp_server smtp.163.com                      #設(shè)置 smtp server 地址，可是ip或域名.可選端口號(hào) （默認(rèn)25）
    smtp_connect_timeout 30                       #設(shè)置 連接 smtp server的超時(shí)時(shí)間
    router_id LVS_DEVEL                           #主機(jī)標(biāo)識(shí)，用于郵件通知
    vrrp_skip_check_adv_addr
    vrrp_strict                                   #嚴(yán)格執(zhí)行VRRP協(xié)議規(guī)范，此模式不支持節(jié)點(diǎn)單播
    vrrp_garp_interval 0
    vrrp_gna_interval 0
    script_user keepalived_script                 #指定運(yùn)行腳本的用戶(hù)名和組。默認(rèn)使用用戶(hù)的默認(rèn)組。如未指定，默認(rèn)為keepalived_script 用戶(hù)，如無(wú)此用戶(hù)，則使用root
    enable_script_security                        #如過(guò)路徑為非root可寫(xiě)，不要配置腳本為root用戶(hù)執(zhí)行。
}
vrrp_instance VI_1 {                              #vrrp 實(shí)例部分定義，VI_1自定義名稱(chēng)
    state MASTER                                  #指定 keepalived 的角色，必須大寫(xiě) 可選值：MASTER|BACKUP
    interface ens33                               #網(wǎng)卡設(shè)置，lvs需要綁定在網(wǎng)卡上，realserver綁定在回環(huán)口。區(qū)別：lvs對(duì)訪問(wèn)為外，realserver為內(nèi)不易暴露本機(jī)信息
    virtual_router_id 51                          #虛擬路由標(biāo)識(shí)，是一個(gè)數(shù)字，同一個(gè)vrrp 實(shí)例使用唯一的標(biāo)識(shí)，MASTER和BACKUP 的 同一個(gè) vrrp_instance 下 這個(gè)標(biāo)識(shí)必須保持一致
    priority 100                                  #定義優(yōu)先級(jí)，數(shù)字越大，優(yōu)先級(jí)越高。
    advert_int 1                                  #設(shè)定 MASTER 與 BACKUP 負(fù)載均衡之間同步檢查的時(shí)間間隔，單位為秒，兩個(gè)節(jié)點(diǎn)設(shè)置必須一樣
    authentication {                              #設(shè)置驗(yàn)證類(lèi)型和密碼，兩個(gè)節(jié)點(diǎn)必須一致
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {                           #設(shè)置虛擬IP地址，可以設(shè)置多個(gè)虛擬IP地址，每行一個(gè)
        192.168.119.130
    }
    track_script {                                #腳本監(jiān)控狀態(tài)
        chk_nginx_service                         #可加權(quán)重，但會(huì)覆蓋聲明的腳本權(quán)重值。chk_nginx_service weight -20
    }
        notify_master "/etc/keepalived/start_haproxy.sh start"  #當(dāng)前節(jié)點(diǎn)成為master時(shí)，通知腳本執(zhí)行任務(wù)
        notify_backup "/etc/keepalived/start_haproxy.sh stop"   #當(dāng)前節(jié)點(diǎn)成為backup時(shí)，通知腳本執(zhí)行任務(wù)
        notify_fault  "/etc/keepalived/start_haproxy.sh stop"   #當(dāng)當(dāng)前節(jié)點(diǎn)出現(xiàn)故障，執(zhí)行的任務(wù);
}
virtual_server 192.168.119.130 80  {          #定義RealServer對(duì)應(yīng)的VIP及服務(wù)端口，IP和端口之間用空格隔開(kāi)
    delay_loop 6                              #每隔6秒查詢(xún)r(jià)ealserver狀態(tài)
    lb_algo rr                                #后端調(diào)試算法（load balancing algorithm）
    lb_kind DR                                #LVS調(diào)度類(lèi)型NAT/DR/TUN
    #persistence_timeout 60                   同一IP的連接60秒內(nèi)被分配到同一臺(tái)realserver
    protocol TCP                              #用TCP協(xié)議檢查realserver狀態(tài)
    real_server 192.168.119.120 80 {
        weight 1                              #權(quán)重，最大越高，lvs就越優(yōu)先訪問(wèn)
        TCP_CHECK {                           #keepalived的健康檢查方式HTTP_GET | SSL_GET | TCP_CHECK | SMTP_CHECK | MISC
            connect_timeout 10                #10秒無(wú)響應(yīng)超時(shí)
            retry 3                           #重連次數(shù)3次
            delay_before_retry 3              #重連間隔時(shí)間
            connect_port 80                   #健康檢查realserver的端口
        }
    }
}
}

[root@localhost ~]# yum -y install nginx
[root@localhost ~]# cd /usr/share/nginx/html/
[root@localhost html]# mv index.html index.html.back
[root@localhost html]# echo "I am 192.168.73.136" > index.html
[root@localhost html]# systemctl start nginx
[root@localhost html]# curl 192.168.73.136
I am 192.168.73.136

[root@localhost ~]# yum install keepalived -y
[root@localhost ~]# rpm -ql keepalived
/etc/keepalived
/etc/keepalived/keepalived.conf  # 主配置文件
/etc/sysconfig/keepalived
/usr/bin/genhash
/usr/lib/systemd/system/keepalived.service
/usr/libexec/keepalived
/usr/sbin/keepalived

[root@localhost ~]# vim /etc/keepalived/check_port.sh
#!/bin/bash
#keepalived 監(jiān)控端口腳本
#使用方法：
#在keepalived的配置文件中
#vrrp_script check_port {#創(chuàng)建一個(gè)vrrp_script腳本,檢查配置
#    script "/etc/keepalived/check_port.sh 80" #配置監(jiān)聽(tīng)的端口
#    interval 2 #檢查腳本的頻率,單位（秒）
#}
CHK_PORT=$1
if [ -n "$CHK_PORT" ];then
        PORT_PROCESS=`ss -lnt|grep $CHK_PORT|wc -l`
        if [ $PORT_PROCESS -eq 0 ];then
                echo "Port $CHK_PORT Is Not Used,End."
                exit 1
        fi
else
        echo "Check Port Cant Be Empty!"
fi
[root@localhost ~]# chmod  +x /etc/keepalived/check_port.sh

[root@localhost ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.168.73.136
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 80"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 251
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.168.73.100
    }
}

! Configuration File for keepalived
global_defs {
        router_id 192.168.73.135
}
vrrp_script chk_nginx {
        script "/etc/keepalived/check_port.sh 80"
        interval 2
        weight -20
}
vrrp_instance VI_1 {
        state BACKUP
        interface ens33
        virtual_router_id 251
        priority 90
        advert_int 1
        authentication {
                auth_type PASS
                auth_pass 11111111
        }
        track_script {
                chk_nginx
        }
        virtual_ipaddress {
                192.168.73.100
        }
}

[root@localhost ~]]systemctl start keepalived && systemctl enable keepalive

[root@localhost keepalived]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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 group default qlen 1000
    link/ether 00:0c:29:6f:74:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.73.136/24 brd 192.168.73.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.73.100/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::af0e:a936:d997:18da/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

# 關(guān)閉主nginx
[root@localhost ~]# systemctl stop nginx
# 查看備上的IP信息，我們發(fā)現(xiàn)vip已經(jīng)偏移到備機(jī)上了
[root@localhost ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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 group default qlen 1000
    link/ether 00:0c:29:6f:74:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.73.136/24 brd 192.168.73.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::af0e:a936:d997:18da/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

[root@zdd211-11 ~]# vim /etc/keepalived/check_keepalived.sh
#!/bin/bash
NGINX_SBIN="which nginx"
NGINX_PORT=80
function check_nginx(){
     NGINX_STATUS="nmap localhost -p ${NGINX_PORT} | grep "80/tcp open" | awk '{print $2}'"
     NGINX_PROCESS="ps -ef | grep nginx|grep -v grep|wc -l"
}
check_nginx
if [ "$NGINX_STATUS" != "open"  -o  $NGINX_PROCESS -lt 2 ]
then
    ${NGINX_SBIN} -s stop
    ${NGINX_SBIN}
    sleep 3
    check_nginx
    if [ "$NGINX_STATUS" != "open"  -o  $NGINX_PROCESS -lt 2 ];then
        systemctl stop keepalived
    fi
 fi
 [root@localhost ~]# chmod  +x /etc/keepalived/check_port.sh

[root@localhost ~]# yum install nmap -y

[root@localhost ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.168.73.136
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 80"
    interval 2
    weight -20
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_keepalive.sh" # 腳本路徑
    interval 2                                  # 執(zhí)行時(shí)間間隔
    weight -5                                   # 計(jì)算權(quán)重值，腳本結(jié)果導(dǎo)致的優(yōu)先級(jí)變更，檢測(cè)失敗（腳本返回非0）則優(yōu)先級(jí) -5
    fall 3                                      # 檢測(cè)連續(xù)3次失敗才算確定是真失敗。會(huì)用weight減少優(yōu)先級(jí)（1-255之間）
    rise 2                                      # 檢測(cè)2次成功就算成功。但不修改優(yōu)先級(jí)
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 251
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.168.73.100
    }
}

! Configuration File for keepalived
global_defs {
        router_id 192.168.73.135
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_keepalive.sh"
    interval 2                     # 執(zhí)行時(shí)間間隔
    weight -5                      # 計(jì)算權(quán)重值，腳本結(jié)果導(dǎo)致的優(yōu)先級(jí)變更，檢測(cè)失敗（腳本返回非0）則優(yōu)先級(jí) -5
    fall 3                         # 檢測(cè)連續(xù)3次失敗才算確定是真失敗。會(huì)用weight減少優(yōu)先級(jí)（1-255之間）
    rise 2                         # 檢測(cè)2次成功就算成功。但不修改優(yōu)先級(jí)
vrrp_instance VI_1 {
        state BACKUP
        interface ens33
        virtual_router_id 251
        priority 90
        advert_int 1
        authentication {
                auth_type PASS
                auth_pass 11111111
        }
        track_script {
                chk_nginx
        }
        virtual_ipaddress {
                192.168.73.100
        }
}

[root@localhost ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.168.73.136
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_keepalive.sh" # 腳本路徑
    interval 2                                  # 執(zhí)行時(shí)間間隔
    weight -5                                   # 計(jì)算權(quán)重值，腳本結(jié)果導(dǎo)致的優(yōu)先級(jí)變更，檢測(cè)失敗（腳本返回非0）則優(yōu)先級(jí) -5
    fall 3                                      # 檢測(cè)連續(xù)3次失敗才算確定是真失敗。會(huì)用weight減少優(yōu)先級(jí)（1-255之間）
    rise 2                                      # 檢測(cè)2次成功就算成功。但不修改優(yōu)先級(jí)
}
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 251
    priority 100
    advert_int 1
    nopreempt    ##不搶VIP 機(jī)制
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.168.73.100
    }
}

global_defs
{
  ``router_id LVS_19
  ``vrrp_mcast_group4 224.0.0.19` `#指定多播地址
}