RHCE第六次作业

1、判断当前磁盘剩余空间是否有20G，如果小于20G，则将报警邮件发送给管理员，每天检查一次磁盘剩余空间。

 （1）、服务端和客户端安装mailx和postfix

#服务端
[root@server ~]# yum install postfix -y
[root@server ~]# systemctl enable postfix --now
 
#客户端
[root@client ~]# yum install sendmail -y

（2）、编写脚本

[root@redhat9 shellwenjian]# vim ade.sh
#!/bin/bash
mb=`df -m / | awk 'NR==2{print $4}'`
gb=$[mb/1024]
if [ "$gb" -lt 20 ]
then
        echo "您最近的磁盘空间已经小于20G，请及时查看！" |  mail -s "WORNING!" root@localhost
fi
[root@redhat9 shellwenjian]# cat /etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
 
# For details see man 4 crontabs
 
# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name  command to be executed
0 0 * * * root /shellwenjian/ade.sh

2、判断web服务是否运行 

（1）、查看进程的方式判断该程序是否运行

（2）、通过查看端口的方式判断该程序是否运行），如果没有运行，则启动该服务。

        （1）、下载httpd包

[root@server ~]# yum install httpd -y

        （2）、编写脚本

[root@server ~]# vim httpd.sh
 
#!/bin/bash
##############################################################
# File Name: httpd.sh
# Version: V1.0
# Author: xx
# Email: xx@163.com
# Organization: http://www.xx.com/xx/
# Created Time : 2023-05-21 16:20:15
# Description:
##############################################################
ps_httpd=`ps -ef | grep httpd | grep -v grep | wc -l`
if [[ $ps_httpd > 0 ]];then
  echo "httpd.server is runing"
else
  systemctl start httpd
  systemctl stop firewalld
fi
                                             

        （3）、运行检测

[root@server ~]# bash httpd.sh 
httpd.server is runing

3、使用curl命令访问第二题的web服务，看能否正常访问，如果能正常访问，则返回web server is running；如果不能正常访问，返回12状态码。

（1）、编写脚本

[root@server ~]# vim web.sh
 
#!/bin/bash
##############################################################
# File Name: web.sh
# Version: V1.0
# Author: xx
# Email: xx@163.com
# Organization: http://www.xx.com/xx/
# Created Time : 2023-05-21 16:27:01
# Description:
##############################################################
curl -s 192.168.186.139 > /dev/null
if [[ $? = 0 ]];then
  echo "web server is runing"
else
  exit 12
fi

  （  2）、运行测试

[root@server ~]# systemctl restart httpd
[root@server ~]# systemctl status httpd
● httpd.service - The Apache HTTP Server
     Loaded: loaded (/usr/lib/systemd/system/httpd.service; disabled; ven>
     Active: active (running) since Sun 2023-05-21 16:31:37 CST; 8s ago
       Docs: man:httpd.service(8)
   Main PID: 5895 (httpd)
     Status: "Started, listening on: port 80"
      Tasks: 213 (limit: 10756)
     Memory: 47.9M
        CPU: 82ms
     CGroup: /system.slice/httpd.service
             ├─5895 /usr/sbin/httpd -DFOREGROUND
             ├─5896 /usr/sbin/httpd -DFOREGROUND
             ├─5897 /usr/sbin/httpd -DFOREGROUND
             ├─5898 /usr/sbin/httpd -DFOREGROUND
             └─5899 /usr/sbin/httpd -DFOREGROUND
 
5月 21 16:31:35 server.hostname.com systemd[1]: Starting The Apache HTTP >
[root@server ~]# bash web.sh 
web server is runing
[root@server ~]# systemctl stop httpd
[root@server ~]# bash web.sh 
[root@server ~]# echo $?
12
[root@server ~]#