Ubuntu安装keepalive

前言

nginx使用docker部署；keepalived使用传统部署。准备两台服务器：192.168.1.6 和192.168.1.7

部署keepalived

keepalived可以将多个无状态的单点通过虚拟IP(VIP)漂移的方式搭建成一个高可用服务

官网

下载

这里下载最新的版本V2.2.7：

先决条件-安装基础依赖

#RHEL/CentOS

yum install curl gcc openssl-devel libnl3-devel net-snmp-devel


# Ubuntu
apt-get install curl gcc libssl-dev libnl-3-dev libnl-genl-3-dev libsnmp-dev

tar -xzvf keepalived-2.2.7.tar.gz

cd keepalived-2.2.7

./configure --prefix=/usr/local/keepalived-2.2.7 --sysconf=/etc

prefix：keepalived安装位置
sysconf：keepalived配置文件位置，默认/etc

编译

make

安装

sudo make install

配置

创建/etc/keepalived/keepalived.conf配置文件：

主节点(MASTER)的配置：


global_defs {
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 1
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
}

子节点(BACKUP)的配置：

global_defs {
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 2
    priority 90
    advert_int 1
    nopreemt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
}

解释：

state MASTER 表示该节点为主节点；

virtual_router_id 1 虚拟路由id，取值范围0-255，主节点(MASTER)和子节点(BACKUP)不要设置一致；

interface ens33 指定网卡名称，使用ip addr查看；

advert_int 1 主、子节点心跳频率，单位为秒

mcast_src_ip 192.168.1.6 指定节点的IP地址；

authentication 用户名密码，主节点(MASTER)和子节点(BACKUP)设置一致；

virtual_ipaddress { 192.168.1.100 }虚拟IP（VIP）地址，待会测试就是使用该IP地址访问；最好跟服务器同一个网段；主节点(MASTER)和子节点(BACKUP)设置一致；

添加到系统服务

创建 keepalived.service 文件

[Unit]
Description=Keepalived
After=network.target

[Service]
ExecStart=/usr/local/keepalived-2.2.7/sbin/keepalived -D
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
Type=forking

[Install]
WantedBy=multi-user.target

请确保将 ExecStart 的路径 /usr/local/keepalived-2.2.7/sbin/keepalived 替换为你 Keepalived 实际安装的路径

将创建的 keepalived.service 文件移动到 /etc/systemd/system/ 目录中：

sudo mv keepalived.service /etc/systemd/system/

重新加载 systemd 配置

sudo systemctl daemon-reload

启动 Keepalived 服务

sudo systemctl start keepalived

重启

systemctl restart keepalived

停止

systemctl stop keepalived

查看运行状态

systemctl status keepalived

开机自启

systemctl enable keepalived

主节点和子节点都启动keepalived，通过VIP访问，默认访问到主节点

检测Nginx状态

设置检测Nginx状态防止一个NGINX不可用导致整个keepalive不可用

编写脚本，通过脚本来检测nginx的启用状态，nginx停止了则尝试重启nginx，若重启失败则停止keepalived

创建/etc/keepalived/nginx_check.sh脚本：

#!/bin/bash

A=$(docker inspect --format='{{.State.Status}}' keep-nginx)

if [ "$A" == "exited" ]; then
    echo "nginx死掉了！正在重启"
    docker restart keep-nginx
    echo "重启完成，检测重启结果...."
    sleep 4
    B=$(docker inspect --format='{{.State.Status}}' keep-nginx)
    if [ "$B" == "exited" ]; then
        echo "nginx重启失败！正在停止keepalived...."
        systemctl stop keepalived
        echo "keepalived停止成功！"
    else
        echo "nginx重启成功！"
    fi
else
    echo "nginx正常运行！"
fi

A=$(docker inspect --format='{{.State.Status}}' keep-nginx) 使用 docker inspect 命令获取名为 "keep-nginx" 的容器的状态，并将其赋值给变量 A

假设你的 Docker 容器名称为 "keep-nginx"，请根据你实际的容器名称进行调整

修改nginx_check.sh权限

chmod +x nginx_check.sh

修改keepalived.conf配置文件

主节点(MASTER)的配置：

global_defs {
   router_id LVS_DEVEL
}

vrrp_script chk_nginx {
   script "/etc/keepalived/nginx_check.sh"
   interval 2
   weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 1
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
    
    track_script {
        chk_nginx 
   }
}

vrrp_script chk_nginx定义一个脚本名为chk_nginx， track_script 用于定义跟踪脚本

子节点(BACKUP)的配置：

global_defs {
   router_id LVS_DEVEL
}

vrrp_script chk_nginx {
   script "/etc/keepalived/nginx_check.sh"
   interval 2
   weight -20
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 2
    priority 90
    advert_int 1
    nopreemt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
    track_script {
        chk_nginx 
   }
}

重启主、子节点的keepalived