Keepalived

Keepalived安装部署

1. 下载地址：
   点我下载
2. 通过ftp工具上传到linux中，/home/software
   
3. 解压
   tar -zxvf keepalived-2.0.18.tar.gz
4. 解压后进入到解压出来的目录，看到会有 configure ，那么就可以做配置了（配置安装和nginx一模一样）
   

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配置 Keepalived - 主

1. 通过命令 vim keepalived.conf 打开配置文件

   global_defs {
   # 路由id：当前安装keepalived的节点主机标识符，保证全局唯一
   router_id keep_171
   }
   vrrp_instance VI_1 {
   # 表示状态是MASTER主机还是备用机BACKUP
   state MASTER
   # 该实例绑定的网卡
   interface ens33
   # 保证主备节点一致即可
   virtual_router_id 51
   # 权重，master权重一般高于backup，如果有多个，那就是选举，谁的权重高，谁就当选
   priority 100
   # 主备之间同步检查时间间隔，单位秒
   advert_int 2
   # 认证权限密码，防止非法节点进入
   authentication {
   auth_type PASS
   auth_pass 1111
   }
   # 虚拟出来的ip，可以有多个（vip）
   virtual_ipaddress {
   192.168.1.161
   }
   }

   附：查看网卡名称
   

2. 启动 Keepalived
   在sbin目录中进行启动（同nginx），如下图：
   

---

配置 Keepalived - 备

1. 通过命令 vim keepalived.conf 打开配置文件

   global_defs {
   router_id keep_172
   }
   vrrp_instance VI_1 {
   # 备用机设置为BACKUP
   state BACKUP
   interface ens33
   virtual_router_id 51
   # 权重低于MASTER
   priority 80
   advert_int 2
   authentication {
   auth_type PASS
   auth_pass 1111
   }
   virtual_ipaddress {
   # 注意：主备两台的vip都是一样的，绑定到同一个vip
   192.168.1.161
   }
   }

2. 启动 Keepalived

   # 启动keepalived
   systemctl start keepalived
   # 停止keepalived
   systemctl stop keepalived
   # 重启keepalived
   systemctl restart keepalived

3. 查看进程

   ps -ef|grep keepalived

   

---

Keepalived配置Nginx自动重启

1. 增加Nginx重启检测脚本

   vim /etc/keepalived/check_nginx_alive_or_not.sh

   #!/bin/bash
   A=`ps -C nginx --no-header |wc -l`
   # 判断nginx是否宕机，如果宕机了，尝试重启
   if [ $A -eq 0 ];then
   /usr/local/nginx/sbin/nginx
   # 等待一小会再次检查nginx，如果没有启动成功，则停止keepalived，使其启动备用机
   sleep 3
   if [ `ps -C nginx --no-header |wc -l` -eq 0 ];then
   killall keepalived
   fi
   fi

   增加运行权限

   chmod +x /etc/keepalived/check_nginx_alive_or_not.sh

2. 配置keepalived监听nginx脚本

   vrrp_script check_nginx_alive {
   script "/etc/keepalived/check_nginx_alive_or_not.sh"
   interval 2 # 每隔两秒运行上一行脚本
   weight 10 # 如果脚本运行失败，则升级权重+10
   }

3. 在 vrrp_instance 中新增监控的脚本

   track_script {
   check_nginx_alive # 追踪 nginx 脚本
   }

4. 重启Keepalived使得配置文件生效

   systemctl restart keepalived

---

配置Keepalived双主热备
规则：以一个虚拟ip分组归为同一个路由
主节点配置：

global_defs {
router_id keep_171
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.161
}
}
vrrp_instance VI_2 {
state BACKUP
interface ens33
virtual_router_id 52
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.162
}
}

备用节点配置

global_defs {
router_id keep_172
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.161
}