微服务实战系列（十）-网关高可用之中间件Keepalived

た入场券 2022-12-11 10:24 27阅读 0赞

### 1.场景描述 ###

因为要做网关的高可用，用到了keepalived+nginx，来保证nginx的高可用，如下图：

![29181bf64f3c8e34d112893319bb8e86.png][]

安装了keepavlived，走了一些弯路，记录下吧，nginx的安装就不多说了，博客已经介绍了好几篇了。

### 2. 解决方案 ###

#### 2.1 安装keepalived ####

##### 2.1.1 安装相关依赖包 #####

[root@t-ruanjianlaowang ~]# yum install -y libnl*
    [root@t-ruanjianlaowang ~]#  yum install -y libnfnetlink-devel zlib zlib-devel gcc gcc-c++ openssl openssl-devel openssh

假如连不了，网上也有这些包的下载，下载后tar解压也行。

##### 2.1.2 下载并安装keepalived #####

官网地址：[https://www.keepalived.org/download.html][https_www.keepalived.org_download.html]

我们使用的最新版本：keepalived-2.0.18.tar.gz，993k

tar -zxvf keepalived-2.0.18.tar.gz
    cd keepalived-2.0.18/
    ./configure --prefix=/usr/local/keepalived
    make
    make install

##### 2.1.3 添加keepavlived为系统服务 #####

[root@t-ruanjianlaowang ~]#  cp /usr/local/keepalived/etc/sysconfig/keepalived  /etc/sysconfig/keepalived 
    
    [root@t-ruanjianlaowang ~]#  cp /usr/local/keepalived/sbin/keepalived /usr/sbin/keepalived
    
    [root@t-ruanjianlaowang ~]# cp /root/tools/keepalived-2.0.18/keepalived/etc/init.d/keepalived   /etc/init.d/keepalived
    
    #/etc/keepalived下好像有了keepalived文件夹，有了就不用mkdir了，软件老王
    [root@t-ruanjianlaowang ~]# mkdir /etc/keepalived  
    [root@t-ruanjianlaowang ~]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf

##### 2.1.4 设置开机启动 #####

# 设置开机启动
    [root@t-ruanjianlaowang ~]# chkconfig keepalived on
    
    [root@t-ruanjianlaowang ~]# service keepalived start|stop|restart

到这里仅仅是keepalived安装完成，接下来还要根据项目项目配置keepalived.conf信息。

如果你觉得文章对你有些帮助，欢迎微信搜索「软件老王」第一时间阅读或交流！

#### 2.2 配置文件修改 ####

##### 2.2.1 master的conf配置文件 #####

vi cd /etc/keepalived/keepalived.conf

!Configuration File for keepalived
    global_defs {
       router_id RUANJIANLAOWANG_MASTER
    }
    
    vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh"
    interval 2
    weight -20
    }
    
    vrrp_instance VI_1 {
    state MASTER
    interface ens666    #这里必须非常注意，软件老王刚开始没太注意，这里是你的网卡名称
    virtual_router_id 81  #这个会在backup机器上用到
    priority 100
    advert_int 1
    authentication {
    auth_type PASS
    auth_pass 1111
    }
    
    track_script {
    chk_nginx
    }
    virtual_ipaddress {
    10.192.168.21
    }
    }

##### 2.2.2 还有个检查nginx是否挂掉的sh，也上传下 #####

vi nginx_check.sh

#!/bin/bash
    counter=$(ps -C nginx --no-heading|wc -l)
    if [ "${counter}" = "0" ]; then
        /usr/sbin/nginx
        sleep 2
        counter=$(ps -C nginx --no-heading|wc -l)
        if [ "${counter}" = "0" ]; then
            /etc/init.d/keepalived stop
        fi
    fi

##### 2.2.3 backup机器上conf文件 #####

/bin/bash: Configuration: command not found
    bal_defs {
     router_id RUANJIANLAOWANG2
    }
    vrrp_script chk_nginx {
    script "/etc/keepalived/nginx_check.sh" ## 检测 nginx 状态的脚本路径
    interval 2 ## 检测时间间隔
    weight -20 ## 如果条件成立，权重-20
    }
    
    vrrp_instance VI_1 {
    state BACKUP
    interface ens168
    virtual_router_id 81
    
    priority 90
    advert_int 1
    authentication {
    auth_type PASS
    auth_pass 111track_script {
               chk_nginx ## 执行 Nginx 监控的服务，软件老王
     }
    virtual_ipaddress {
    10.192.168.21
        }
    }

这里记着也把检查nginx的sh文件上传上，跟master上的一样。

#### 2.3 启动 ####

（1）配置完成后开始启动

[root@t-ruanjianlaowang ~]# service keepalived start

（2）启动过程中，打开日志看一下（刚开始可能会有问题，看下日志啥都明白了）

[root@t-ruanjianlaowang ~]# tail -f  /var/log/messages

（3）假如启动不了，可以尝试以下方式。

[root@t-ruanjianlaowang ~]# systemctl daemon-reload
    
    #上面试过后，不行再重新注册服务
    [root@t-ruanjianlaowang ~]#chkconfig --del keepalived
    [root@t-ruanjianlaowang ~]# cd /usr/lib/systemd/system/
    [root@t-ruanjianlaowang ~]#rm -rf keepalived.service
    [root@t-ruanjianlaowang ~]# chkconfig --add keepalived

#### 2.4 验证 ####

[root@t-ruanjianlaowang ~]#ip addr show ens666
    [root@t-ruanjianlaowang ~]#ip addr show ens168
    ens666、ens168为网卡名称
    
    假如绑定成功，软件老王机器里显示的信息里面会有：10.192.168.21的显示

--------------------

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![在这里插入图片描述][20200918154804757.jpg_pic_center]

[29181bf64f3c8e34d112893319bb8e86.png]: /images/20221123/5c2df36059904d1ca3df2ef1125e502b.png
[https_www.keepalived.org_download.html]: https://www.keepalived.org/download.html
[20200918154804757.jpg_pic_center]: /images/20221123/08c9d6ee0f9d4dc6ab8eb824a723ad1d.png