shell scripting for my automation process.

suboss87 · 02-11-2013, 05:00 AM

Hi,
I need to write a Shell or Perl script for updating iptables on Linux servers, Let me explain the concept.
need to change iptable entries for many our servers located at different countries, so script would be run by any users.
Let us keep it as 3-locations(india, singapore, malaysia) each location has different ip's.

my sample script

Code:

#/bin/bash
india=10.31.0.1
singapore=10.31.0.2
malaysia=10.31.0.3

echo "Enter the country name:"
read country
if [ `$country=$singapore` ]
sed -i /192.168.0.1/$singapore/" /etc/sysconfig/iptables
else
  echo "error"

fi

OUTPUT sample:

./ipchange.sh

Enter the country name: singapore
(after entering the country name, script should verify and update the user required country ip-address. So everything will be embedded with the script)

ipatables updated sucessfully.

Kindly help me out to create a clear script for the same.

Regards,
Subash.

unSpawn · 02-11-2013, 07:05 AM

Quote:

Originally Posted by suboss87

I need to write a Shell or Perl script for updating iptables on Linux servers, Let me explain the concept. need to change iptable entries for many our servers located at different countries, so script would be run by any users. Let us keep it as 3-locations(india, singapore, malaysia) each location has different ip's.

Instead of

Code:

if [ `$country=$singapore` ]

you can use a case statement and for example 'getopts' or 'select' to make a selection.

Instead of

Code:

sed -i /192.168.0.1/$singapore/" /etc/sysconfig/iptables

I suggest you use 'mktemp', work on a copy of 'iptables-save' output and make a backup of the current rule set and allow for restoration (at or cron job) on error.

*More importantly you should think about your "country list". What happens if a country gets a second location added? How about addresses? Does each location have only one, fixed IPv4 address? What happens if it changes? If one gets added? These questions don't only apply script-wise but where the script could or should be retrieved from, how you will keep it up to date between locations and who will be responsible for timely modifications.

Code:

function help() { echo "Bash scripting guides:
http://www.tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html 
http://www.tldp.org/LDP/Bash-Beginners-Guide/html/index.html 
http://www.gnu.org/software/bash/manual/html_node/index.html
http://www.grymoire.com/Unix/Sh.html
http://www.tldp.org/LDP/abs/html/ 
http://mywiki.wooledge.org/BashFAQ
http://mywiki.wooledge.org/BashPitfalls"; }