EC2 Allocation Script

allocate.bash

#!/bin/bash


# This script is used to allocate a large number of IP addresses on EC2
# and associate them with network interfaces
#
# It gets the list of network interfaces

#TODO: You don't actually need instance_id, i don't think
if [ $# -eq 0 ] ; then
echo "Usage: $0 <instance_id>"
exit 1
fi

#Instance id
instance_id=$1

#Number of IPs to register
ips=1

#Maximum number of IPs per interface. I believe this is 30. I could be wrong.
max_ip_per_interfaces=30

#Get a list of ENIs
eni_list=( $(ec2-describe-network-interfaces | grep eni | nawk -F"\\t" '{print $2}') )

#Get the number of ENIs
eni_count=${#eni_list[@]}

echo "EC2 IP Allocation Script Starting.."
echo ""
echo "[+] Using instance_id: ${instance_id}"
echo "[+] Got ENIs: ${eni_list[*]}"

assigned_count=-1

for ((i = 0; i < ips; i++))
do

	if [ $[$i % $max_ip_per_interfaces] == 0 ]; then
		((assigned_count++))
		echo "[+] Using network interface: ${eni_list[$[assigned_count]]}"
	fi

	#Assign ip
	output=($(ec2-allocate-address -d vpc | nawk -F"\\t" '{print $2 " " $5}'))
	
	eip="${output[1]}"
	ip="${output[0]}"

	echo "[+] Allocated ( eip , ip ) : ( ${eip} , ${ip} ) "

	echo "[+] Associating.."
	ec2-associate-address -n ${eni_list[$[assigned_count]]}  -a ${eip}

	if [ "${?}" -gt 0 ]; then
		echo "[-] Error occurred. See above, fix it and run again. You may need to delete and start over."
		exit 1
	fi

	echo "[+] Association completed without error"
done

echo "Done!"