nginx主备+keepalived实现高可用

1、上传nginx安装包、nginx_check.sh脚本到 /opt目录。

[root@localhost opt]# ll
-rw-r--r--. 1 root root 808876 Jun 8 15:36 nginx-1.20.1-1.el7.ngx.x86_64.rpm
-rw-r--r--. 1 root root 190 Aug 19 14:31 nginx_check.sh

2、nginx_check.sh脚本内容：

#!/bin/bash
A=`ps -C nginx – no-header |wc -l`
if [ $A -eq 0 ];then
  systemctl start nginx
  sleep 2
  if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
    killall keepalived
  fi
fi

3、执行安装。脚本添加可执行权限

chmod +x nginx_check.sh
sudo yum install -y nginx-1.16.1-1.el7.ngx.x86_64.rpm

4、启动Nginx并设置开机启动

systemctl start nginx.service
systemctl enable nginx.service

5、查看Nginx版本

nginx -v

查看Nginx启动状态

systemctl status nginx.service
nginx监听的是：80端口

注意：以上步骤需要在2台服务器做同样操作。

keepalived实现高可用

1、直接使用yum安装

yum -y install keepalived

2、编辑keepalived配置文件
vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id zz01
   vrrp_skip_check_adv_addr
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_script chk_http_port {
    script "/etc/nginx/nginx_check.sh"
    interval 2
    weight 2
}

vrrp_instance VI_1 {
    state MASTER
    interface ens192
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    track_script {
        chk_http_port
}

    virtual_ipaddress {
        172.16.40.220
    }
}

3、启动keepalived、添加开机自启动

systemctl start keepalived
systemctl enable keepalived

4、查看keepalived状态、

systemctl status keepalived

5、查看vip状态：ip a

2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:50:56:a6:b9:1c brd ff:ff:ff:ff:ff:ff
    inet 10.2.0.53/24 brd 10.2.0.255 scope global ens192
       valid_lft forever preferred_lft forever
    inet 10.2.0.49/32 scope global ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::e142:af5a:8b12:2259/64 scope link 
       valid_lft forever preferred_lft forever

此时，网卡已经有虚拟ip，nginx+keepalived高可用已建立。