Boot Strap : MySQL

Here is a user data boot strap script for installing and starting Oracle MySQL:

#!/bin/sh 

yum -y install mysql-server 

/etc/init.d/mysqld start 

echo -e '\n\nsudo /etc/init.d/mysqld start' >> /etc/rc.d/rc.local

Boot strap : NAT Instance

This is the user data boot strap script which 'makes' your EC2 instance into a NAT instance:
#!/bin/sh

echo 1 > /proc/sys/net/ipv4/ip_forward

echo 0 > /proc/sys/net/ipv4/conf/eth0/send_redirects

/sbin/iptables -t nat -A POSTROUTING -o eth0 -s 0.0.0.0/0 -j MASQUERADE

/sbin/iptables-save > /etc/sysconfig/iptables

mkdir -p /etc/sysctl.d/

cat <<EOF > /etc/sysctl.d/nat.conf

net.ipv4.ip_forward = 1

net.ipv4.conf.eth0.send_redirects = 0

EOF

Boot strap PHP and ELB examples

Here is strap script that can be used to install and start Apache along with PHP.  It will then download and unzip the AWS ELB examples.

yum -y install httpd php

chkconfig httpd on

/etc/init.d/httpd start

cd /var/www/html

wget http://bootstrapping-assets.s3.amazonaws.com/examplefiles-elb.zip

unzip examplefiles-elb.zip

Packer for single source AMI configuration

I talk about boot strapping on this blog post:
http://cloudconclave.blogspot.com/2013/08/boot-strapping-with-user-data-and.html

Another method of single source configuration for EC2 instances without getting into the dilemma of 'AMI sprawl' is to use Packer. More on the use of Packer here:
http://blog.controlgroup.com/2013/10/21/packer-cloudformation-power-couple/