A monitor script for checking security of servers聲牙在職期間所寫的一個

checkServer a shell script to check whether the Cpu or Memory of a server is normal, which will send emails to notify when it's not. Before using it, you have to set up some tools before.

1. Mutt

This script has used Mutt server to send emails, so you must setup it first.
Mutt: mutt is an email client for linux in terminal, which supports POP and IMAP.

Ubuntu

Install Mutt

The system name can be set any name as like as you are.

Set Configuration

set .muttrc in the ~ directory of root user.

# .mutttrc file
# sudo vi ~/.muttrc or /root/.muttrc
set envelope_from=yes
# the name of who sent the mail
set from=xxx@soundtooth.cn
# the real name of who send the mail
set realname="VoiceIn Website"
set use_from=yes
set rfc2047_parameters=yes
set charset="utf-8"

Send Emails

echo "Email Contents" | `which mutt` -s "Title" aleen42@vip.qq.com

Fedora/CentOS

more details in www.wilf.cn/post/centos…

2. Crontab

If you want to run the script at a fixed time, you can use Crontab.

Set tasks in crontab

# crontab -e
# if the terminal asks you to choose an editor, I recommend the third one, 'vim-baic'.
# Edit this file to introduce tasks to be run by cron.
# 
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
# 
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').# 
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
# 
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
# 
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
# 
# For more information see the manual pages of crontab(5) and cron(8)
# 
# m h  dom mon dow   command
# excute each 9pm every day to give general notification when set "true"
0 21 * * * sh /home/checkServer/checkServer.sh true
# excute each hour to give special notification like 'memory warning' when set "false"
0 * * * * sh /home/checkServer/checkServer.sh false

3. Shell

Parameters

MAX_mem(%): the upper edge of physical memory warning.
MAX_cpu(%): the upper edge of physical cpu warning.
DELAY(s): update every [delay] seconds.
COUNT: update [count] times.
NORMAL_CHECK: to identify whether it's normal check each day.
sh_command: point out where sh command is.
top_command: point out where top command is.
sar_command: point out where sar command is.
iostat_command: point out where iostat command is.
free_command: point out where free command is.

Methods

checkServer(): generate system info and send emails to the specifical email address.

Extract Number

get the row 3 and column 3 of top command:

`free | sed -n "3, 1p" | awk '{print int($3)}'`

Attention

sar command need to set ENABLED to be true in /etc/default/sysstat.

#
# Default settings for /etc/init.d/sysstat, /etc/cron.d/sysstat
# and /etc/cron.daily/sysstat files
#

# Should sadc collect system activity informations? Valid values
# are "true" and "false". Please do not put other values, they
# will be overwritten by debconf!
ENABLED="true"

# Additional options passed to sa1 by /etc/init.d/sysstat
# and /etc/cron.d/sysstat
# By default contains the `-S DISK' option responsible for
# generating disk statisitcs.
SA1_OPTIONS="-S DISK"

# Additional options passed to sa2 by /etc/cron.daily/sysstat.
SA2_OPTIONS=""

if ENABLED is not true, you may get the following result when runing sar

root@xxx:/home/checkServer# sar
Cannot open /var/log/sysstat/sa16: No such file or directory
Please check if data collecting is enabled in /etc/default/sysstat

4. MySQL

This script also monitor the mysql.log whether there're some unexpected operations like DELETE and DROP TABLE. Before you run this script, you have to enable log of your MySQL by following the tutorial. If there're some problems about mysql.log, you can check it on your server, or just check the email of operations item. clearMySQLManually is a shell script for cleanning mysql.log safely in manual.

5. How to use

Clone

git clone https://github.com/SoundTooth/checkServer.git

Check commands

Excute

# options:
#   true: normal check
#   false: warning check
# email_addr: the email you want to receive infos of the server
sh ./checkServer/checkServer.sh

Check with crontab

# Normal Check at 9 pm.
0 21 * * * sh ~/checkServer/checkServer.sh true aleen42@vip.qq.com

# Clear MySQLLog automatically if there are not exceptions
0 21 * * * sh ~/checkServer/clearMySQLLog.sh

# Warning Check within each 10 minutes
*/10 * * * * sh ~/checkServer/checkServer.sh false aleen42@vip.qq.com

⛽ How to contribute

Have an idea? Found a bug? See how to contribute.

A monitor script for checking security of servers