#!/bin/bash

VERBOSITY=0
TEMP_D=""
DEF_DISK_FORMAT="raw"
DEF_FILESYSTEM="iso9660"
CR="
"

error() { echo "$@" 1>&2; }
fail() { [ $# -eq 0 ] || error "$@"; exit 1; }

Usage() {
	cat <<EOF
Usage: ${0##*/} [ options ] output user-data [meta-data]

   Create a disk for cloud-init to utilize nocloud

   options:
     -h | --help             show usage
     -d | --disk-format D    disk format to output. default: raw
                             can be anything supported by qemu-img or
                             tar, tar-seed-local, tar-seed-net
     -H | --hostname    H    set hostname in metadata to H
     -f | --filesystem  F    filesystem format (vfat or iso), default: iso9660

     -i | --interfaces  F    write network interfaces file into metadata
     -N | --network-config F write network config file to local datasource
     -m | --dsmode      M    add 'dsmode' ('local' or 'net') to the metadata
                             default in cloud-init is 'net', meaning network is
                             required.
     -V | --vendor-data F    vendor-data file
     -v | --verbose          increase verbosity

   Note, --dsmode, --hostname, and --interfaces are incompatible
   with metadata.

   Example:
    * cat my-user-data
      #cloud-config
      password: passw0rd
      chpasswd: { expire: False }
      ssh_pwauth: True
    * echo "instance-id: \$(uuidgen || echo i-abcdefg)" > my-meta-data
    * ${0##*/} my-seed.img my-user-data my-meta-data
    * kvm -net nic -net user,hostfwd=tcp::2222-:22 \\
         -drive file=disk1.img,if=virtio -drive file=my-seed.img,if=virtio
    * ssh -p 2222 ubuntu@localhost
EOF
}

bad_Usage() { Usage 1>&2; [ $# -eq 0 ] || error "$@"; exit 1; }
cleanup() {
	[ -z "${TEMP_D}" -o ! -d "${TEMP_D}" ] || rm -Rf "${TEMP_D}"
}

debug() {
	local level=${1}; shift;
	[ "${level}" -gt "${VERBOSITY}" ] && return
	error "${@}"
}

has_cmd() {
	command -v "$1" >/dev/null 2>&1
}

short_opts="hH:i:d:f:m:N:o:V:v"
long_opts="disk-format:,dsmode:,filesystem:,help,hostname:,interfaces:,"
long_opts="${long_opts}network-config:,output:,vendor-data:,verbose"
getopt_out=$(getopt --name "${0##*/}" \
	--options "${short_opts}" --long "${long_opts}" -- "$@") &&
	eval set -- "${getopt_out}" ||
	bad_Usage

## <<insert default variables here>>
output=""
userdata=""
metadata=""
vendordata=""
filesystem=""
diskformat=$DEF_DISK_FORMAT
interfaces=_unset
dsmode=""
hostname=""
ncname="network-config"


while [ $# -ne 0 ]; do
	cur=${1}; next=${2};
	case "$cur" in
		-h|--help) Usage ; exit 0;;
		-d|--disk-format) diskformat=$next; shift;;
		-f|--filesystem) filesystem=$next; shift;;
		-H|--hostname) hostname=$next; shift;;
		-i|--interfaces) interfaces=$next; shift;;
		-N|--network-config) netcfg=$next; shift;;
		-m|--dsmode) dsmode=$next; shift;;
		-v|--verbose) VERBOSITY=$((${VERBOSITY}+1));;
		-V|--vendor-data) vendordata="$next";;
		--) shift; break;;
	esac
	shift;
done

## check arguments here
## how many args do you expect?
[ $# -ge 2 ] || bad_Usage "must provide output, userdata"
[ $# -le 3 ] || bad_Usage "confused by additional args"

output=$1
userdata=$2
metadata=$3

if [ -n "$metadata" ]; then
	[ "$interfaces" = "_unset" -a -z "$dsmode" -a -z "$hostname" ] ||
		fail "metadata is incompatible with:" \
			"--interfaces, --hostname, --dsmode"
fi

case "$diskformat" in
	tar|tar-seed-local|tar-seed-net)
		if [ "${filesystem:-tar}" != "tar" ]; then
			fail "diskformat=tar is incompatible with filesystem"
		fi
		filesystem="$diskformat"
		;;
	tar*)
		fail "supported 'tar' formats are tar, tar-seed-local, tar-seed-net"
esac

if [ -z "$filesystem" ]; then
	filesystem="$DEF_FILESYSTEM"
fi
if [ "$filesystem" = "iso" ]; then
	filesystem="iso9660"
fi

case "$filesystem" in
	tar*)
		has_cmd tar ||
			fail "missing 'tar'. Required for --filesystem=$filesystem";;
	vfat)
		has_cmd mkfs.vfat ||
			fail "missing 'mkfs.vfat'. Required for --filesystem=vfat."
		has_cmd mcopy ||
			fail "missing 'mcopy'. Required for --filesystem=vfat."
		;;
	iso9660)
		has_cmd genisoimage ||
			fail "missing 'genisoimage'.  Required for --filesystem=iso9660."
		;;
	*) fail "unknown filesystem $filesystem";;
esac

case "$diskformat" in
	tar*|raw) :;;
	*) has_cmd "qemu-img" ||
		fail "missing 'qemu-img'.  Required for --disk-format=$diskformat."
esac

[ "$interfaces" = "_unset" -o -r "$interfaces" ] ||
	fail "$interfaces: not a readable file"

TEMP_D=$(mktemp -d "${TMPDIR:-/tmp}/${0##*/}.XXXXXX") ||
	fail "failed to make tempdir"
trap cleanup EXIT

files=( "${TEMP_D}/user-data" "${TEMP_D}/meta-data" )
if [ -n "$metadata" ]; then
	cp "$metadata" "$TEMP_D/meta-data" || fail "$metadata: failed to copy"
else
	instance_id="iid-local01"
	iface_data=""
	[ "$interfaces" != "_unset" ] &&
		iface_data=$(sed ':a;N;$!ba;s/\n/\\n/g' "$interfaces")

	# write json formatted user-data (json is a subset of yaml)
	mdata=""
	for kv in "instance-id:$instance_id" "local-hostname:$hostname" \
		"interfaces:${iface_data}" "dsmode:$dsmode"; do
		key=${kv%%:*}
		val=${kv#*:}
		[ -n "$val" ] || continue
		mdata="${mdata:+${mdata},${CR}}\"$key\": \"$val\""
	done
	printf "{\n%s\n}\n" "$mdata" > "${TEMP_D}/meta-data"
fi

if [ -n "$netcfg" ]; then
	cp "$netcfg" "${TEMP_D}/$ncname" ||
		fail "failed to copy network config"
	files[${#files[@]}]="$TEMP_D/$ncname"
fi

if [ -n "$vendordata" ]; then
	cp "$vendordata" "${TEMP_D}/vendor-data" ||
		fail "failed to copy vendor data"
	files[${#files[@]}]="$TEMP_D/vendor-data"
fi

files_rel=( )
for f in "${files[@]}"; do
	files_rel[${#files_rel[@]}]="${f#${TEMP_D}/}"
done

if [ "$userdata" = "-" ]; then
	cat > "$TEMP_D/user-data" || fail "failed to read from stdin"
else
	cp "$userdata" "$TEMP_D/user-data" || fail "$userdata: failed to copy"
fi

## alternatively, create a vfat filesystem with same files
img="$TEMP_D/seed-data"
tar_opts=( --owner=root --group=root )

case "$filesystem" in
	tar)
		tar "${tar_opts[@]}" -C "${TEMP_D}" -cf "$img" "${files_rel[@]}" ||
			fail "failed to create tarball of ${files_rel[*]}"
		;;
	tar-seed-local|tar-seed-net)
		if [ "$filesystem" = "tar-seed-local" ]; then
			path="var/lib/cloud/seed/nocloud"
		else
			path="var/lib/cloud/seed/nocloud-net"
		fi
		mkdir -p "${TEMP_D}/${path}" ||
			fail "failed making path for seed files"
		mv "${files[@]}" "${TEMP_D}/$path" ||
			fail "failed moving files"
		tar "${tar_opts[@]}" -C "${TEMP_D}" -cf "$img" "${path}" ||
			fail "failed to create tarball with $path"
		;;
	iso9660)
		genisoimage -output "$img" -volid cidata \
			-joliet -rock "${files[@]}" > "$TEMP_D/err" 2>&1 ||
			{ cat "$TEMP_D/err" 1>&2; fail "failed to genisoimage"; }
		;;
	vfat)
		truncate --size 128K "$img" || fail "failed truncate image"
		out=$(mkfs.vfat -n cidata "$img" 2>&1) ||
			{ error "failed: mkfs.vfat -n cidata $img"; error "$out"; }
		mcopy -oi "$img" "${files[@]}" :: ||
			fail "failed to copy user-data, meta-data to img"
		;;
esac

[ "$output" = "-" ] && output="$TEMP_D/final"
if [ "${diskformat#tar}" != "$diskformat" -o "$diskformat" = "raw" ]; then
	cp "$img" "$output" ||
		fail "failed to copy image to $output"
else
	qemu-img convert -f raw -O "$diskformat" "$img" "$output" ||
		fail "failed to convert to disk format $diskformat"
fi

[ "$output" != "$TEMP_D/final" ] || { cat "$output" && output="-"; } ||
	fail "failed to write to -"

debug 1 "wrote ${output} with filesystem=$filesystem and diskformat=$diskformat"
# vi: ts=4 noexpandtab