This is a modification of the original Upstart script. It is intended for those that get the latest binary downloads.

docker.conf

description "Docker daemon"

start on filesystem
stop on runlevel [!2345]

respawn

pre-start script
  # see also https://github.com/tianon/cgroupfs-mount/blob/master/cgroupfs-mount
  if grep -v '^#' /etc/fstab | grep -q cgroup \
    || [ ! -e /proc/cgroups ] \
    || [ ! -d /sys/fs/cgroup ]; then
    exit 0
  fi
  if ! mountpoint -q /sys/fs/cgroup; then
    mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
  fi
  (
    cd /sys/fs/cgroup
    for sys in $(awk '!/^#/ { if ($4 == 1) print $1 }' /proc/cgroups); do
      mkdir -p $sys
      if ! mountpoint -q $sys; then
        if ! mount -n -t cgroup -o $sys cgroup $sys; then
          rmdir $sys || true
        fi
      fi
    done
  )
end script

script
  docker -d
end script