实验场景： 我使用keepalived保证nginx的高可用，我想知道什么时候ip发生漂移，可以让ip发生漂移的时候 我的邮箱收到消息.

如果对keepalived不了解，这有详细解释：keepalived与nginx与MySQL-CSDN博客https://blog.csdn.net/m0_59933574/article/details/134189200?spm=1001.2014.3001.5501

实验步骤：

Nginx通过Upstream模块实现负载均衡

主机清单：

主机名	IP	系统	用途
Proxy-master	192.168.231.201	centos7.5	主负载
Proxy-slave	192.168.231.202	centos7.5	主备
Real-server1	192.168.231.203	Centos7.5	web1
Real-server2	192.168.231.204	centos7.5	Web2
Vip for proxy	192.168.231.225

所有机器都配置安装nginx，关闭防火墙与selinux

[root@proxy-master ~]# systemctl stop firewalld         //关闭防火墙
[root@proxy-master ~]# sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/sysconfig/selinux        //关闭selinux，重启生效
[root@proxy-master ~]# setenforce 0        　　　　　　　　//关闭selinux，临时生效安装nginx， 全部4台
[root@proxy-master ~]# cd /etc/yum.repos.d/
[root@proxy-master yum.repos.d]# vim nginx.repo
[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=0
enabled=1
[root@proxy-master yum.repos.d]# yum install yum-utils -y
[root@proxy-master yum.repos.d]# yum install nginx -y

实验过程

1、选择两台nginx服务器作为代理服务器。
2、给两台代理服务器安装keepalived制作高可用生成VIP
3、配置nginx的负载均衡

选择201  202为代理服务器

201
# vim /etc/nginx/nginx.conf#Nginx配置文件
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {worker_connections 1024;
}
http {log_format  main  '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';access_log  /var/log/nginx/access.log  main;sendfile            on;tcp_nopush          on;tcp_nodelay         on;keepalive_timeout   65;types_hash_max_size 2048;include             /etc/nginx/mime.types;default_type        application/octet-stream;include /etc/nginx/conf.d/*.conf;upstream backend {     ####管理服务器组，设置权重server 192.168.231.204:80 weight=1 max_fails=3 fail_timeout=20s;server 192.168.231.203:80 weight=1 max_fails=3 fail_timeout=20s;}server {listen       80;server_name  localhost;location / {proxy_pass http://backend;proxy_set_header Host $host:$proxy_port;proxy_set_header X-Forwarded-For $remote_addr;}}
}

202 
# vim /etc/nginx/nginx.confuser nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/*.conf;
events {worker_connections 1024;
}
http {log_format  main  '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';access_log  /var/log/nginx/access.log  main;sendfile            on;tcp_nopush          on;tcp_nodelay         on;keepalive_timeout   65;types_hash_max_size 2048;include             /etc/nginx/mime.types;default_type        application/octet-stream;include /etc/nginx/conf.d/*.conf;upstream backend {    server 192.168.231.204:80 weight=1 max_fails=3 fail_timeout=20s;server 192.168.231.203:80 weight=1 max_fails=3 fail_timeout=20s;}server {listen       80;server_name  localhost;location / {proxy_pass http://backend;proxy_set_header Host $host:$proxy_port;proxy_set_header X-Forwarded-For $remote_addr;}}
}

Keepalived实现调度器HA

主备都安装keepalived

[root@zhu ~]# yum install -y keepalived[root@bei ~]# yum install -y keepalived#主备都进行的操作cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak#主备都修改配置文件vim /etc/keepalived/keepalived.conf#这是主的配置文件
! Configuration File for keepalivedglobal_defs {router_id directory1   #辅助改为directory2
}vrrp_instance VI_1 {state MASTER        #定义主还是备interface ens33     #VIP绑定接口virtual_router_id 80  #整个集群的调度器一致priority 100         #back改为50advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.231.225/24   # vip}
}#这是备的配置文件
! Configuration File for keepalivedglobal_defs {router_id directory2
}vrrp_instance VI_1 {state BACKUP    #设置为backupinterface ens33nopreempt        #设置到back上面，不抢占资源virtual_router_id 80priority 50   #辅助改为50advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.231.225/24}
}

主备均启动keepalived

开机自启
# systemctl enable keepalived
启动
systemctl start keepalived查看ip[root@zhu ~]# ip a | grep 225inet 192.168.231.225/24 scope global secondary ens33

对调度器Nginx健康检查（可选）两台都设置

思路：
让Keepalived以一定时间间隔执行一个外部脚本，脚本的功能是当Nginx失败，则关闭本机的Keepalived

主服务器
vim  check_nginx_status.sh #!/bin/bash										             
/usr/bin/curl -I http://localhost &>/dev/null	
if [ $? -ne 0 ];then									         
#	/etc/init.d/keepalived stopsystemctl stop keepalived
fi	备服务器
vim  check_nginx_status.sh #!/bin/bash										             
/usr/bin/curl -I http://localhost &>/dev/null	
if [ $? -ne 0 ];then									         
#	/etc/init.d/keepalived stopsystemctl stop keepalived
fi	给主备的脚本的执行权限！！！！
chmod +x check_nginx_status.sh 

将脚本引用在keepalived的配置文件中

主服务器的keepalived的配置文件
! Configuration File for keepalivedglobal_defs {router_id directory1  
}
vrrp_script check_nginx {      #引用脚本script "/etc/keepalived/check_nginx_status.sh"interval 5
}
vrrp_instance VI_1 {state MASTER       interface ens33    virtual_router_id 80 priority 100        advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.231.225/24  }
track_script {check_nginx}
}

备服务器的keepalived的配置文件
[root@bei ~]# vim /etc/keepalived/keepalived.conf! Configuration File for keepalived
global_defs {router_id directory2
}
vrrp_script check_nginx {script "/etc/keepalived/check_nginx_status.sh"interval 5
}
vrrp_instance VI_1 {state BACKUP   interface ens33nopreempt       virtual_router_id 80priority 50  advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.231.225/24}track_script {check_nginx}
}

现在我们就可以实现keepalived的高可用，实现IP漂移，如何以邮件的方式收到呢

我们以QQ邮箱为例

我是自己给自己发，因此我的收件人与发件人 都写了自己的QQ

获取最重要的授权码，授权码拿到手以后

在主备服务器进行相同的操作

主备均下载yum install -y mailx编写配置文件
vim /etc/mail.rcset bsdcompat
set from=xxxxxxxxx@qq.com    ###发送者
set smtp=smtp.qq.com
set smtp-auth-user=xxxxxxxxx@qq.com
set smtp-auth-password=jawypsdsdsddbeg     ####前面获取到的授权码
set smtp-auth=login
set ssl-verify=ignore

主备编写邮件脚本

主备均进行的操作
cd /etc/keepalived/vim sendmail.sh#!/bin/bash
to_email='xxxxxxxx@qq.com'     #这是收件人，
ipaddress=`ip -4 a show dev ens33 | awk '/brd/{print $2}'`
notify() {mailsubject="${ipaddress}to be $1, vip转移"mailbody="$(date +'%F %T'): vrrp 飘移, $(hostname) 切换到 $1"echo "$mailbody" | mail -s "$mailsubject" $to_email
}
case $1 in
master)notify master;;
backup)notify backup;;
fault)notify fault;;
*)echo "Usage: $(basename $0) {master|backup|fault}"exit 1;;
esac

记得给脚本执行权限  chmod  +x sendmail.sh

在keepalived的配置文件内引用邮件脚本，主备的配置文件都需要操作

! Configuration File for keepalivedglobal_defs {router_id directory1  
}vrrp_script check_nginx {script "/etc/keepalived/check_nginx_status.sh"interval 5
}vrrp_instance VI_1 {state MASTER       interface ens33    virtual_router_id 80 priority 100        advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.231.225/24  }track_script {check_nginx}#引用邮件脚本，主备都只需要加这三行即可notify_master "/etc/keepalived/sendmail.sh master"notify_backup "/etc/keepalived/sendmail.sh backup"notify_fault "/etc/keepalived/sendmail.sh fault"}

系统重载，让所有配置文件都重新加载一下

主备都进行
systemctl daemon-reload

开始演示

此时我们的vip在备服务器上

[root@bei ~]# ip a | grep 225inet 192.168.231.225/24 scope global secondary ens33

我们开启主服务器的nginx服务，以及keepalived

[root@zhu ~]# systemctl start  nginx [root@zhu ~]# systemctl start keepalived

按照脚本，vip也会从备漂移到主服务器

[root@bei ~]# ip a | grep 225
[root@bei ~]# root@zhu ~]# ip a | grep 225inet 192.168.231.225/24 scope global secondary ens33

收到邮件

实验注意事项

1.写完脚本记得给执行权限

2.每次修改完配置文件记得要重启服务

3.获取qq授权码比较繁琐