Script for running docker in Chrome OS

docker-from-chromeos.sh

#!/bin/sh
## Requires custom kernel to be installed in Chrome OS
## Copies files from my archlinux chroot into a temp folder and runs docker from there.
## Running this on boot of Chrome OS so my version of the docker daemon is upgraded by
## pacman in the chroot.

set -e
chroot=/usr/local/chroots/arch
run=/usr/local/tmp/docker

[ -f /etc/init/crouton.conf -a `whoami` = root ] || {
        echo "$0: must be run as root from Chrome OS"
        exit 2
}
egrep -q '^docker:' /etc/group || {
        echo "$0: group docker not found, add something like 'docker:x:996:chronos' to /etc/group - as GID use same as docker group in the chroot"
        exit 2
}
pgrep -x docker > /dev/null && {
        echo "$0: docker is already running"
        exit 1
}
[ -d /sys/fs/cgroup/cpuset ] || {
        mkdir -p /sys/fs/cgroup/cpuset
        mount -t cgroup none /sys/fs/cgroup/cpuset -o cpuset
}
mkdir -p $run
cp -v $chroot/usr/bin/docker $chroot/usr/lib/docker/dockerinit $chroot/usr/lib/libdevmapper* $run
export LD_LIBRARY_PATH=$run
$run/docker -D -d -H unix:///tmp/docker.sock "$@" > $chroot/var/log/docker.log 2>&1