Create a custom AMI using Canonical provided images

custom-ubuntu-ami.sh

#!/bin/bash

## Refer: http://alestic.com/2010/01/ec2-ebs-boot-ubuntu ##

# create directory structure
mkdir -p $HOME/image

# download, extract and mount image
cd $HOME
wget "http://cloud-images.ubuntu.com/releases/precise/release/ubuntu-12.04-server-cloudimg-amd64.tar.gz"
tar xf ubuntu-12.04-server-cloudimg-amd64.tar.gz
sudo mount -o loop precise-server-cloudimg-amd64.img $HOME/image

# define some variables
IMGDIR="$HOME/image"
ARCH="x86_64"
SIZE=8 # root disk size in gigs
NOW=$(date +%Y%m%d-%H%M)
PREFIX="ubuntu-12.04-precise-server-amd64-$NOW"
DESCRIPTION="Ubuntu 12.04 Precise Server amd64 $NOW"
EBSOPTS="--block-device-mapping /dev/sdb=ephemeral0 --kernel=aki-88aa75e1"

# export ec2 creds
export EC2_CERT=$(echo /home/ubuntu/.ec2/cert-*.pem)
export EC2_PRIVATE_KEY=$(echo /home/ubuntu/.ec2/pk-*.pem)

# create & attach volume with ext4 fs
VOLUMEID=$(ec2-create-volume --size $SIZE --availability-zone us-east-1b | cut -f2)
INSTANCEID=$(wget -qO- http://instance-data/latest/meta-data/instance-id)
ec2-attach-volume --device /dev/sdc --instance "$INSTANCEID" "$VOLUMEID"
while [ ! -e /dev/xvdc ]; do echo -n .; sleep 1; done
sudo mkfs.ext4 -F /dev/xvdc # 12.04 FS image is ext4

# mount newly created volume and put 12.04 image on it
EBSIMAGE=$IMGDIR-ebs
mkdir -p $EBSIMAGE
sudo mount /dev/xvdc $EBSIMAGE
sudo tar -Svcf - -C $IMGDIR . | sudo tar xvf - -C $EBSIMAGE
sudo umount $EBSIMAGE

# detach volume and create a snapshot
ec2-detach-volume "$VOLUMEID"
SNAPID=$(ec2-create-snapshot "$VOLUMEID" | cut -f2)
ec2-delete-volume "$VOLUMEID"

while ec2-describe-snapshots "$SNAPID" | grep -q pending
do
  echo -n .
  sleep 1
done

# create ami using snapshot
ec2-register --architecture $ARCH --name "$PREFIX" --description "$DESCRIPTION" $EBSOPTS --snapshot "$SNAPID"