live-build/scripts/build/chroot_tmpfs

#!/bin/sh

## live-build(7) - System Build Scripts
## Copyright (C) 2016-2020 The Debian Live team
## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
##
## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
## This is free software, and you are welcome to redistribute it
## under certain conditions; see COPYING for details.


set -e

# Including common functions
[ -e "${LIVE_BUILD}/scripts/build.sh" ] && . "${LIVE_BUILD}/scripts/build.sh" || . /usr/lib/live/build.sh

# Setting static variables
DESCRIPTION="Use tmpfs to speedup the build"
USAGE="${PROGRAM} {install|remove} [--force]"

# Processing arguments and configuration files
Init_config_data "${@}"

if [ "${LB_BUILD_WITH_TMPFS}" != "true" ]
then
	exit 0
fi

# Requiring stage file
Require_stagefiles config bootstrap

case "${1}" in
	install)
		Echo_message "Configuring tmpfs for /var/lib/dpkg"

		# Checking stage file
		Check_stagefile

		# Acquire lock file
		Acquire_lockfile

		mv chroot/var/lib/dpkg chroot/var/lib/dpkg.tmp
		mkdir chroot/var/lib/dpkg
		mount -t tmpfs -o x-gvfs-hide tmpfs chroot/var/lib/dpkg
		mv chroot/var/lib/dpkg.tmp/* chroot/var/lib/dpkg
		rm -rf chroot/var/lib/dpkg.tmp

		# Creating stage file
		Create_stagefile
		;;

	remove)
		Echo_message "Deconfiguring tmpfs for /var/lib/dpkg"

		# Acquire lock file
		Acquire_lockfile

		mkdir -p chroot/var/lib/dpkg.tmp
		mv chroot/var/lib/dpkg/* chroot/var/lib/dpkg.tmp
		umount chroot/var/lib/dpkg
		rm -rf chroot/var/lib/dpkg
		mv chroot/var/lib/dpkg.tmp chroot/var/lib/dpkg

		# Removing stage file
		Remove_stagefile
		;;

	*)
		Usage --fail
		;;
esac