umorpha-boxes/bin/mkbootstrapiso

#!/usr/bin/env bash
# Copyright (C) 2023  Umorpha Systems
# SPDX-License-Identifier: AGPL-3.0-or-later

set -euE -o pipefail

main() {
	local arg_rootfs_img arg_iso_img
	arg_rootfs_img=$1
	arg_iso_img=$2

	local basename
	basename=${arg_rootfs_img##*/}
	basename=${basename%%.*}

	SOURCE_DATE_EPOCH=${SOURCE_DATE_EPOCH:-"$(date +%s)"}

	local label
	label="${basename^^}_$(TZ=UTC date --date="@$SOURCE_DATE_EPOCH" +%Y%m%d_%H%M%S)"

	local workdir
	workdir="$(mktemp -dt "${0##*/}.XXXXXXXXXX")"
	trap "rm -rf -- ${workdir@Q}" EXIT

	mkdir -- "$workdir/mnt"
	sudo osi-mount --user -- images/bootstrap.rootfs.img "$workdir/mnt" \
	     cp -T --recursive --dereference -- "$workdir/mnt/boot" "$workdir/iso"

	echo "  APPEND iso=LABEL=${label}" >>"$workdir/iso/isolinux/syslinux.cfg"

	cp -- "$arg_rootfs_img" "$workdir/iso/rootfs.img"


	sudo osi-mount --user -- images/bootstrap.rootfs.img "$workdir/mnt" \
	     xorriso \
		\
		-no_rc \
		-report_about SORRY \
		\
		-as mkisofs \
		\
		-iso-level 3 \
		-full-iso9660-filenames \
		-joliet \
		-joliet-long \
		-rational-rock \
		-volid "$label" \
		-appid "Umorpha ${basename} bootstrap installer" \
		-publisher "Umorpha Systems <https://umorpha.io>" \
		-preparer "prepared by umorpha-boxes mkbootstrapiso" \
		\
		-eltorito-boot    isolinux/isolinux.bin \
		-eltorito-catalog isolinux/boot.cat \
		-no-emul-boot \
		-boot-load-size 4 \
		-boot-info-table \
		\
		-output "$arg_iso_img" \
		"$workdir/iso"
}

main "$@"