Little script to create a minimal ubuntu using debootstrap and bring it up to date

strapwrap.sh

#!/bin/bash
set -e
DEFAULT_PACKAGES=ssh,language-pack-en-base
DEFAULT_COMPONENTS=main,universe
DEBOOTSTRAP=/usr/sbin/debootstrap
DEFAULT_MIRROR=http://archive.ubuntu.com/ubuntu
DEFAULT_VARIANT=minbase

MIRROR=${STRAP_MIRROR:-$DEFAULT_MIRROR}
ROOTFS=$1
PACKAGES=${STRAP_PACKAGES:-$DEFAULT_PACKAGES} 
COMPONENTS=${STRAP_COMPONENTS:-$DEFAULT_COMPONENTS}
SUITE=${STRAP_SUITE:-precise}
VARIANT=${STRAP_VARIANT:-$DEFAULT_VARIANT}

type $DEBOOTSTRAP >/dev/null
if [ $? -ne 0 ]; then
    echo "debootstrap not installed"
    exit 1
fi

if [ "x$ROOTFS" == "x" ]; then 
    echo "Usage: $0 <path_to_root>"
    exit 1
fi

$DEBOOTSTRAP --include $PACKAGES --components $COMPONENTS --variant $VARIANT $SUITE $ROOTFS $MIRROR

cat > $ROOTFS/etc/apt/sources.list << EOF
deb $MIRROR $SUITE ${COMPONENTS//,/ }
deb $MIRROR $SUITE-updates ${COMPONENTS//,/ }
deb $MIRROR $SUITE-security ${COMPONENTS//,/ }
EOF

chroot $ROOTFS mount -t proc /proc /proc
chroot $ROOTFS apt-get update
chroot $ROOTFS apt-get dist-upgrade -y
umount $ROOTFS/proc