案例五：shell脚本实现定时监控http服务的运行状态

注意：监控方法可以为端口、进程、URL模拟访问方式，或者三种方法综合。

说明：由于截止到目前仅讲了if语句，因此，就请大家用if语句来实现。

　　[root@oldboy-B scripts]# cat apachemon

　　#!/bin/sh

　　#created by oldboy 20110523

　　. /etc/init.d/functions

　　HTTPPRONUM=`ps -ef|grep http|grep -v grep|wc -l`

　　#if [ $HTTPPRONUM -lt 1 ];then

　　if [[ $HTTPPRONUM -lt 1 ]];then

　　action “httpd is not running” /bin/false

　　action “httpd is not running” /bin/false >/tmp/httpd.log

　　httpdctl restart >/dev/null 2>&1

　　action “httpd is restart” /bin/true

　　mail -s “`uname -n`’s httpd restarted at `(date)`” 31333741@qq.com

　　exit 1

　　else

　　action “httpd is running” /bin/true

　　exit 0

　　fi

　　[root@oldboy-B scripts]# apachemon

　　httpd is running [确定]

　　[root@oldboy-B scripts]# pkill httpd

　　[root@oldboy-B scripts]# ps -ef |grep http |grep -v grep

　　[root@oldboy-B scripts]# apachemon

　　httpd is not running [失败]

　　httpd is restart [确定]

　　[root@oldboy-B scripts]# ps -ef|grep http|grep -v grep

　　root 5845 1 1 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5852 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5853 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5854 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5855 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5856 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5857 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5858 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart

　　apache 5859 5845 0 15:59 ? 00:00:00 /usr/sbin/httpd -k restart
 

脚本改进

　　[root@oldboy-B /]# echo oldboytest >/var/www/html/index.htm

　　[root@oldboy-B /]# wget –quiet –spider http://10.0.0.161/index.htm

　　[root@oldboy-B /]# echo $?

　　0

　　[root@oldboy-B /]# ll index.htm

　　ls: index.htm: 没有那个文件或目录

　　[root@oldboy-B scripts]# cat apachemon1

　　#!/bin/sh

　　#created by oldboy 20110523

　　

　　. /etc/init.d/functions

　　#HTTPPRONUM=`ps -ef|grep http|grep -v grep|wc -l` #=====>这个是基于http方式进行判断

　　wget –quiet –spider http://10.0.0.161/index.htm #=====>这个是基于WGET URL方式进行判断

　　if [ $? -ne 0 ];then

　　action “httpd is not running” /bin/false >/tmp/httpd.log

　　httpdctl restart >/dev/null 2>&1

　　action “httpd is restart” /bin/true >>/tmp/httpd.log

　　mail -s “`uname -n`’s httpd restarted at `(date)`” mail@qq.com

　　exit 1

　　else

　　action “httpd is running” /bin/true

　　exit 0

　　fi

真正使用时，有些输出是不需要的就去掉

　　[root@oldboy-B scripts]# cat apachemon1

　　#!/bin/sh

　　#created by oldboy 20110523

　　#

　　. /etc/init.d/functions

　　wget –quiet –spider http://10.0.0.161/index.htm #=====>这个是基于WGET URL方式进行判断

　　if [ $? -ne 0 ];then

　　action “httpd is not running” /bin/false >/tmp/httpd.log

　　httpdctl restart >/dev/null 2>&1

　　action “httpd is restart” /bin/true >>/tmp/httpd.log

　　mail -s “`uname -n`’s httpd restarted at `(date)`” 31333741@qq.com

　　exit 1

　　fi

多条件判断的写法

　　[root@oldboy-B scripts]# cat apachemon1

　　#!/bin/sh

　　#created by oldboy 20110523

　　#

　　. /etc/init.d/functions

　　HTTPPORTNUM=`netstat -lnt|grep 80|grep -v grep|wc -l`

　　HTTPPRONUM=`ps -ef|grep http|grep -v grep|wc -l`

　　wget –quiet –spider http://10.0.0.161/index.htm && RETVAL=$?

　　if [ $RETVAL -ne 0 ] || [ $HTTPPORTNUM -ne 1 ] || [ $HTTPPRONUM -lt 1 ] ;then

　　#if [ "$RETVAL" != "0" -o "$HTTPPORTNUM" != "1" -o "$HTTPPRONUM" \< "1" ] ;then

　　action “httpd is not running” /bin/false

　　action “httpd is not running” /bin/false >/tmp/httpd.log

　　httpdctl restart >/dev/null 2>&1

　　action “httpd is restart” /bin/true

　　mail -s “`uname -n`’s httpd restarted at `(date)`” 31333741@qq.com

　　exit 1

　　else

　　action “httpd is running” /bin/true

　　exit 0

　　fi