livecd-rootfs/live-build/lb_chroot_layered

#!/bin/sh

## live-build(7) - System Build Scripts
## Copyright (C) 2006-2012 Daniel Baumann <daniel@debian.org>
##
## 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.

## This is a fork of lb_chroot for layered live system.
## We don't want leaking host configuratino in each layer, and so,
## we clean and setup the chroot each time.
## In addition, we create the squashfs for each layer, but top one (live)
## which still can be configured after lb chroot call.

set -e

# Including common functions
( . "${LIVE_BUILD}/scripts/build.sh" > /dev/null 2>&1 || true ) || . /usr/lib/live/build.sh

# Automatically populating config tree
if [ -x auto/config ] && [ ! -e .build/config ]
then
	Echo_message "Automatically populating config tree."
	lb config
fi

# Setting static variables
DESCRIPTION="$(Echo 'customize the Debian system')"
HELP=""
USAGE="${PROGRAM} [--force]"

Arguments "${@}"

# Reading configuration files
Read_conffiles config/all config/common config/bootstrap config/chroot config/binary config/source
Set_defaults

# Setup cleanup function
Setup_cleanup

. config/functions

teardownPath="config/teardown_chroot_layered"
cat >> $teardownPath << EOF
#!/bin/sh
set -e
EOF
chmod +x $teardownPath

PASSES="${PASSES:-install live}"
CURPASS=1
LASTPASS=$(echo $PASSES|wc -w)
for _PASS in $PASSES
do

	if [ $CURPASS -gt 1 ]; then
		mkdir chroot.${_PASS}
		mount_overlay chroot/ "chroot.${_PASS}/" chroot/
		cat >> $teardownPath << EOF		
umount chroot/
EOF
	fi

	# Configuring chroot
	lb chroot_cache restore ${*}
	lb chroot_devpts install ${*}
	lb chroot_proc install ${*}
	lb chroot_selinuxfs install ${*}
	lb chroot_sysfs install ${*}
	lb chroot_debianchroot install ${*}
	lb chroot_dpkg install ${*}
	lb chroot_tmpfs install ${*}
	lb chroot_sysv-rc install ${*}
	lb chroot_upstart install ${*}
	lb chroot_hosts install ${*}
	lb chroot_resolv install ${*}
	lb chroot_hostname install ${*}
	lb chroot_apt install ${*}
	lb chroot_archives chroot install ${*}

	# Customizing chroot
	lb chroot_linux-image ${*}
	lb chroot_preseed ${*}
	lb chroot_early_hooks ${*}

	lb chroot_package-lists ${_PASS} ${*}
	lb chroot_install-packages ${_PASS} ${*}

	# Kernel should be in first layer
	if [ $CURPASS -eq 1 ]; then
		Chroot chroot "dpkg -l linux-headers-3* linux-headers-4*" 2>/dev/null \
			| awk '/^i/ {print $2}' > chroot.headers
		for i in $(cat chroot.headers); do
			Chroot chroot "apt-mark auto $i"
		done
	fi

	Chroot chroot "apt-get --purge -y autoremove"

	# Add live packages to top layer
	if [ $CURPASS -eq $LASTPASS ]; then
		lb chroot_live-packages ${*}
	fi

	lb chroot_includes ${*}
	# TODO: look if this is what copies distro hooks
	lb chroot_hooks ${*}
	lb chroot_hacks ${*}
	lb chroot_interactive ${*}

	Chroot chroot "dpkg-query -W" > chroot.packages.${_PASS}

	# Deconfiguring chroot
	lb chroot_archives chroot remove ${*}
	lb chroot_apt remove ${*}
	lb chroot_hostname remove ${*}
	lb chroot_resolv remove ${*}
	lb chroot_hosts remove ${*}
	lb chroot_sysv-rc remove ${*}
	lb chroot_upstart remove ${*}
	lb chroot_tmpfs remove ${*}
	lb chroot_dpkg remove ${*}
	lb chroot_debianchroot remove ${*}
	lb chroot_sysfs remove ${*}
	lb chroot_selinuxfs remove ${*}
	lb chroot_proc remove ${*}
	lb chroot_devpts remove ${*}
	lb chroot_cache save ${*}

	if [ $CURPASS -eq 1 ]; then
		cp -a chroot chroot.${_PASS}
	fi
	
	CURPASS=$(( CURPASS + 1 ))
done

# Remove unused chroot binary corresponding to bottom layer (once everything is unmount)
cat >> $teardownPath << EOF		
rm -rf chroot/
EOF