关于keepalived:Keepalived

Keepalived 装置部署

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. 解压后进入到解压进去的目录，看到会有 configure，那么就能够做配置了（配置装置和 nginx 截然不同）
   

配置 Keepalived – 主

1. 通过命令 vim keepalived.conf 关上配置文件

   global_defs {
   # 路由 id：以后装置 keepalived 的节点主机标识符，保障全局惟一
   router_id keep_171
   }
   vrrp_instance VI_1 {
   # 示意状态是 MASTER 主机还是备用机 BACKUP
   state MASTER
   # 该实例绑定的网卡
   interface ens33
   # 保障主备节点统一即可
   virtual_router_id 51
   # 权重，master 权重个别高于 backup，如果有多个，那就是选举，谁的权重高，谁就入选
   priority 100
   # 主备之间同步查看工夫距离，单位秒
   advert_int 2
   # 认证权限明码，避免非法节点进入
   authentication {
   auth_type PASS
   auth_pass 1111
   }
   # 虚构进去的 ip，能够有多个（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 关上配置文件

   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 {
   # 留神：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
   # 进行 keepalived
   systemctl stop keepalived
   # 重启 keepalived
   systemctl restart keepalived

3. 查看过程

   ps -ef|grep keepalived

Keepalived 配置 Nginx 主动重启

1. 减少 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
   # 期待一小会再次查看 nginx，如果没有启动胜利，则进行 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

   减少运行权限

   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，则降级权重 +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 使得配置文件失效

   systemctl restart keepalived

配置 Keepalived 双主热备
规定：以一个虚构 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}