Updates AWS Security Group adding or updating your current IP address therefore allowing you to access sg restricted stuff

aws-grant-access.sh

#!/bin/bash
 
# By Ed Wiget; 
# Modified by Rafael Cintra (artnic)
# This run via cron whenever my ip address changes in order to update aws security group
# Or you can put it before accessing anything restricted
 
# 20131120 - original script
# 20150325 - artnic custom; pointing to bitsforest ;)

##### VARIABLES TO SET ##########################
 
# set our home directory which holds our ip file
HOMEDIR=~
 
# set the name of the security group as show in aws console
SEC_GROUP=webservers-default
 
##### END VARIABLES TO SET ######################
 
# here we check for the aws binary and if it dont exist we bail cause sysadmin silly to try to run this script
 
which aws
if [ $? = 0 ]; then
	echo ""
else
	echo "Silly rabbit, sysadmin ain't for kids. Just a tip: awscli"
	exit 1
fi
 
# first we check for existing file
if [ -f ${HOMEDIR}/.amazonip ]; then
	# if it exists, we create a backup for comparison
	cp ${HOMEDIR}/.amazonip ${HOMEDIR}/.amazonip.old
	# then grab the current ip
	WAN=`curl -s http://bitsforest.com/ip.php`
	# and populate the new file
	echo ${WAN} > ${HOMEDIR}/.amazonip
 
	# here we need to check if the files differ
	diff ${HOMEDIR}/.amazonip ${HOMEDIR}/.amazonip.old
		if [ $? = 0 ]; then
			echo "No IP update required"
			exit 1
		else
			echo "IP update required.... stand by"
			# here we get the value to revoke
			REVOKE=`cat ${HOMEDIR}/.amazonip.old`
			echo "Revoking access to your old IP ${REVOKE}"
			# then revoke the old ip
			aws ec2 revoke-security-group-ingress --group-name ${SEC_GROUP} --protocol tcp --port 22 --cidr ${REVOKE}/32
			# next we set the new ip to allow ssh access
			NEWIP=`cat ${HOMEDIR}/.amazonip`
			# and set the new ip address for ssh access
			echo "Granting access to ${NEWIP}"
			aws ec2 authorize-security-group-ingress --group-name ${SEC_GROUP} --protocol tcp --port 22 --cidr ${NEWIP}/32
			echo "All done!"
		fi
else
 
	# our file didnt exist, so it must be a new system, so lets set it up
	# get the ip
	WAN=`curl -s http://bitsforest.com/ip.php`
	# create the file
	echo ${WAN} > ${HOMEDIR}/.amazonip
	# set the variable so we can add the ip to the systems security group
	NEWIP=`cat ${HOMEDIR}/.amazonip`
	echo "Granting access to ${NEWIP}"
	# and set the new ip address for ssh access
	aws ec2 authorize-security-group-ingress --group-name ${SEC_GROUP} --protocol tcp --port 22 --cidr ${NEWIP}/32
	echo "All done!"
fi