Linux基础-Shell脚本

任务一目标：自动部署、初始配置、并启动nginx反向代理服务

把任务拆分来看-自动部署部分，就是先下载安装Nginx

首先建立一个很NB霸气的目录还有一个同样NB霸气的.sh文件

/NBshell/MissionOne.sh

自动化部署代码如下：

#/bin/bash
systemctl status nginx
if(($?==))
        then
        yum install -y nginx
        if(($?==))
                then
                #echo 'Yes!'
                systemctl start nginx
                if(($?==))
                        then
                        echo "Congratulations!! Nginx start OK!!"
                else
                        echo "Sorry is Fail!!!"
                fi
        else
                echo"sorry install is Fail!!!"

        fi
elif(($?==))
        then
        systemctl start nginx
        if(($?==))
                then
                echo "Congratulations!! Nginx start OK!!!"
        else
                echo "sorry!!"
        fi
elif(($?==))
        then
        echo "OKOKOK!!!"
else
        echo "I am so sorry"
fi

检测系统是否安装nginx如果没有，就安装nginx，并启动

如果已安装未启动，就启动，如果已启动，就万事大吉了！

其次是初始化配置成反向代理，也就是对/etc/nginx/nginx.config进行编辑

使用sed流式编辑工具

 echo "config writing...."
 sed -ri '/^http/a upstream Yanlong {' /etc/nginx/nginx.conf
 sed -ri '/^upst/a server yanlongweb1\;' /etc/nginx/nginx.conf
 sed -ri '/^server yanlongweb1/a server yanlongweb2\;' /etc/nginx/nginx.conf
 sed -ri '/^server yanlongweb2/a \}' /etc/nginx/nginx.conf
 sed -ri '/^(\ +)(location)(\ )(\/)/a proxy_pass http:\/\/Yanlong\;' /etc/nginx/nginx.conf
 echo"config write is OK!"
 systemctl reload nginx
 if(($?==))
         then
         echo "HTTP load balancer is OK!"
 else
         echo "Sorry!!"
 fi

脚本执行成功！服务器配置完成！

任务二目标：自动部署、初始配置、并启动三台web

由于物理环境的限制，只能开启两台WEB服务器分别为yanlongweb1和yanlongweb2

并执行以下脚本对nginx进行安装部署配置，并启动

#/bin/bash
systemctl status nginx
if(($?==))
        then
        yum install -y nginx
        if(($?==))
                then
                #echo 'Yes!'
                systemctl start nginx
                if(($?==))
                        then
                        echo "Congratulations!! Nginx start OK!!"
                else
                        echo "Sorry is Fail!!!"
                fi
        else
                echo"sorry install is Fail!!!"

        fi
elif(($?==))
        then
        systemctl start nginx
        if(($?==))
                then
                echo "Congratulations!! Nginx start OK!!!"
        else
                echo "sorry!!"
        fi
elif(($?==))
        then
        echo "OKOKOK!!!"
else
        echo "I am so sorry"
fi
echo "config writing...."
sed -ri '/^(\ +)(location)(\ )(\/)/a root\ \/nginxwebservice\;' /etc/nginx/nginx.conf
sed -ri '/^root\ \/nginxwebservice/a index\ web.html\;' /etc/nginx/nginx.conf
echo "config write is OK!"
systemctl reload nginx
if(($?==))
        then
        echo "HTTP load balancer YanlongWEBservice is OK!"
else
        echo "Sorry!!"
fi

脚本执行完成，检查服务启动状态

现在进行访问web1

访问web2

任务一中搭建的反向代理：

访问反向代理服务器：192.168.16.119

脚本执行成功！服务器搭建成功

任务三目标：监控脚本：监控每台机器的内存使用率>70%,则输出报警信息

#/bin/bash
bu=`free | awk 'NR==2{print $6}'`
to=`free | awk 'NR==2{print $2}'`
mem=`expr "scale=2;$bu/$to" |bc -l | cut -d. -f2`
while true
do
        if(($mem >= ))
                then
                echo "目前内存使用率是:${mem}%"
                sleep
        fi
done

后台运行./LookMem.sh &

为了实现效果，我将内存的报警阈值调为15%

请看效果