VPN (PPTP) EC2 Setup

#!/bin/bash

# Original steps from: http://www.yzhang.net/blog/2013-03-07-pptp-vpn-ec2.html
#
# Run this in a root bash environment. This assumes a setting similar to Amazon EC2 Linux.
# Otherwise replace the lines that start with "yum" with whatever package manager is used.
# The script will ask for username and password, but if you want to do this programmatically,
# you can set environment variables $vpn_username and $vpn_password, then run with --no-prompt.
#
# After this is all set you should be able to connect to your new machine using VPN. Make
# sure to pick PPTP as the protocol, and use the username/password you have selected.

if [ "$1" != "--no-prompt" ]
then
    echo -n "Username: "
    read vpn_username
    echo -n "Password: "
    read -s vpn_password
    echo
fi


yum -y update
wget http://poptop.sourceforge.net/yum/stable/rhel6/x86_64/pptpd-1.4.0-1.el6.x86_64.rpm
yum -y localinstall pptpd-1.4.0-1.el6.x86_64.rpm
echo localip 192.168.9.1 >> /etc/pptpd.conf
echo remoteip 192.168.9.11-30 >> /etc/pptpd.conf
echo ms-dns    8.8.8.8 >> /etc/ppp/options.pptpd
echo ms-dns    8.8.4.4 >> /etc/ppp/options.pptpd
echo "$vpn_username pptpd $vpn_password *" >> /etc/ppp/chap-secrets
echo net.ipv4.ip_forward = 1 >> /etc/sysctl.conf
/sbin/sysctl -p
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
echo "iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE" >> /etc/rc.local
/sbin/service pptpd start
chkconfig pptpd on