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keepalived 安装 ​

1、安装 ​

安装依赖库 ​

shell
# 安装libnl环境
yum install -y libnl libnl-devel

下载 ​

shell
wget ...

移动 ​

shell
mv keepalived-2.0.18.tar.gz /usr/local
cd /usr/local

解压 ​

shell
tar -xvf keepalived-2.0.18.tar.gz

进行 configure 配置 ​

shell
#进入源码目录
cd /usr/local/keepalived-2.0.18
# 
./configure --prefix=/usr/local/keepalived --sysconf=/etc

说明

执行 configure 时，可使用的命令

命令解释
–prefix指定 keepalived安装目录
--sysconf指定 keepalived配置目录

编译 ​

shell
# 编译及安装
make && make install

启动命令 ​

shell
/usr/local/keepalived/sbin/keepalived //启动

/usr/local/nginx/sbin/nginx -s stop //关闭

/usr/local/nginx/sbin/nginx -s reload //重启

2、配置文件 ​

主节点配置文件

! Configuration File for keepalived

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，默认1s
    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
    }
}

从节点配置文件

! Configuration File for keepalived

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_172
}
vrrp_instance VI_1 {
    # 表示状态是MASTER主机还是备用机BACKUP
    state BACKUP
    # 该实例绑定的网卡
    interface ens33
    # 保证主备节点一致即可
    virtual_router_id 51
    # 权重低于MASTER
    priority 80
    # 主备之间同步检查时间间隔，单位秒，默认1s
    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 {
        #注意：主备两台的vip都是一样的，绑定到同一个vip
        192.168.1.161
    }
}

3、设置开机自启 ​

复制文件

shell
cp /usr/local/keepalived-2.0.18/keepalived/etc/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived-2.0.18/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
systemctl daemon-reload
shell
#开机自启
systemctl enable keepalived.service
#启动
systemctl start keepalived.service
#关闭
systemctl stop keepalived.service
#重启
systemctl restart keepalived.service

4、Keepalived配置Nginx自动重启 ​

（1）增加Nginx重启检测脚本 ​

shell
vim /etc/keepalived/check_nginx_alive_or_not.sh

填入内容

shell
#!/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

shell
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 ​

shell
systemctl restart keepalived