监控 Linux 服务器是否宕机并发送邮件的解决方案

摘自: https://ld246.com/article/1568076441812

1.centos 下安装和配置

yum -y install sendmail
yum -y install mailx

2. mail.rc 新增以下内容

set from=your-email@example.com  
set smtp-auth-user=your-email@example.com
set smtp=smtp.example.com
set smtp-auth-password=your-password
set stmp-auth=login

3.说明：

• from: 对方收到邮件时显示的发件人
• smtp: 指定第三方发送邮件的 smtp 服务器地址
• smtp-auth-user: 第三方发邮件的用户名
• smtp-auth-password: 用户名对应密码(邮箱授权码)
• smtp-auth: SMTP 的认证方式。默认是 LOGIN，也可改为 CRAM-MD5 或 PLAIN 方式

4.编写检测脚本 ping.sh

#!/bin/bash

Date=`date -d "today" +"%Y-%m-%dT%H-%M-%S"`
echo "根据当前时间创建日志文件"

mkdir -p /log/Ping/

touch /log/Ping/${Date}.log

servers="192.168.4.9 192.168.4.10 \
192.168.4.11 192.168.4.12 192.168.4.13 192.168.4.14 \
192.168.4.21 192.168.4.22 192.168.4.23 192.168.4.24 \
192.168.4.31 192.168.4.32 192.168.4.33 192.168.4.34 \
192.168.4.41 192.168.4.42 192.168.4.43 192.168.4.44"

for server in ${servers}
do
  ping_result=`/bin/ping -c 4 ${server} | grep % | awk -F[:" "]+ '{print $6}' | tr -d '%'`
  if [[ ${ping_result} -eq "0" ]]
  then
    echo "${server} is ok"
    echo "${server} is ok"  >> /log/Ping/${Date}.log
  elif [[ ${ping_result} -eq "100" ]]
  then
    echo "${server} is down"
    echo "${server} is down" >> /log/Ping/${Date}.log
  else
    echo "${server} is packet loss"
    echo "${server} is packet loss" >> /log/Ping/${Date}.log
  fi
done

/usr/bin/mail -s " Server Status" your-email@example.com < /log/Ping/${Date}.log
#删除log文件
rm -rf /log/Ping/${Date}.log

5.执行结果:

root@ubuntu:~/server_monitor# bash ping.sh
根据当前时间创建日志文件
192.168.4.9 is ok
192.168.4.11 is ok
192.168.4.12 is ok
192.168.4.13 is ok
192.168.4.14 is ok
192.168.4.21 is ok
192.168.4.22 is ok
192.168.4.23 is ok
192.168.4.24 is ok
192.168.4.31 is ok
192.168.4.32 is ok
192.168.4.33 is ok
192.168.4.34 is ok
192.168.4.41 is ok
192.168.4.42 is ok
192.168.4.43 is ok
192.168.4.44 is ok

6.使用 crontab 定时任务每隔半小时执行检测脚本

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
*/30 * * * * /root/server_monitor/ping.sh > /dev/null &

7.优化

若觉得半个小时时间太频繁，可以设置检测到服务器宕机或者丢包的时候发邮件，正常情况下不发

#!/bin/bash

Date=`date -d "today" +"%Y-%m-%dT%H-%M-%S"`
echo "根据当前时间创建日志文件"

mkdir -p /log/Ping/

touch /log/Ping/${Date}_normal.log
touch /log/Ping/${Date}_unnormal.log

servers="192.168.4.9 192.168.4.10 \
192.168.4.11 192.168.4.12 192.168.4.13 192.168.4.14 \
192.168.4.21 192.168.4.22 192.168.4.23 192.168.4.24 \
192.168.4.31 192.168.4.32 192.168.4.33 192.168.4.34 \
192.168.4.41 192.168.4.42 192.168.4.43 192.168.4.44"

for server in ${servers}
do
  ping_result=`/bin/ping -c 4 ${server} | grep % | awk -F[:" "]+ '{print $6}' | tr -d '%'`
  if [[ ${ping_result} -eq "0" ]]
  then
    echo "${server} is ok"
    echo "${server} is ok"  >> /log/Ping/${Date}_normal.log
  elif [[ ${ping_result} -eq "100" ]]
  then
    echo "${server} is down"
    echo "${server} is down" >> /log/Ping/${Date}_unnormal.log
  else
    echo "${server} is packet loss"
    echo "${server} is packet loss" >> /log/Ping/${Date}_unnormal.log
  fi
done

if [ -s /log/Ping/${Date}_unnormal.log ];then
  echo "不为空，发送邮件"
  /usr/bin/mail -s " Server Status" your-email@example.com < /log/Ping/${Date}_unnormal.log
else
  echo "为空，不发送邮件"
fi
#删除log文件
rm -rf /log/Ping/${Date}_*.log

注意：脚本中的判断条件中 0 和 100 的意思分别为服务器的丢包率，0 为不丢包，100 为全丢包，其余数值为部分丢包，下图可看出效果