Creating a busybox image for lxd

make_busybox

image=$1

if [ -f $image ]; then
    exit 0
fi
path=$(mktemp --directory lxdapi.busybox.XXXXXXXX)
arch=$(uname --machine)

mkdir -p $path/rootfs/{bin,dev,etc,mnt,proc,root,sys,tmp}

# Add an /etc/inittab; this is to work around:
# http://lists.busybox.net/pipermail/busybox/2015-November/083618.html
# Basically, since there are some hardcoded defaults that misbehave, we
# just pass an empty inittab so those aren't applied, and then busybox
# doesn't spin forever.
touch /rootfs/etc/inittab

cat > $path/metadata.yaml <<EOF
architecture: $arch
creation_date: $(date +%s)
properties:
    os: Busybox
    architecture: $arch
    description: Busybox $arch
    name: Busybox-$arch
EOF
cat > $path/metadata.yaml <<EOF
{
    "architecture": "x86_64",
    "creation_date": 1463647974,
    "properties": {
        "architecture": "x86_64",
        "description": "Busybox x86_64",
        "name": "busybox-x86_64",
        "obfuscate": "<function uuid4 at 0x7f7e75833488>",
        "os": "Busybox"
    }
}
EOF

cp $(which busybox) $path/rootfs/bin
$path/rootfs/bin/busybox --install -s $path/rootfs/bin

pushd $path
tar cvJf ../$image .
popd
rm -rf $path