#!/bin/bash
# Copyright (c) 2012 - OpenSLX GmbH
#
# This program is free software distributed under the GPL version 2.
# See http://openslx.org/COPYING
#
# If you have any feedback please consult http://openslx.org/feedback and
# send your feedback to feedback@openslx.org
#
# General information about OpenSLX can be found at http://openslx.org
#
# Server side script to generate stage3.1,2 initial ramfses for OpenSLX Linux
# stateless clients
#############################################################################

# first parameter is a hash pointing to the target directory
# /srv/openslx/build

# in the future the prefix should be set via slxsettings ...

MODULE_DIR=${ROOT_DIR}/server

STAGE31_STATIC_DIR=${ROOT_DIR}/data/stage3.1
STAGE31_DIR=${MODULE_DIR}/stage3.1
STAGE32_DIR=${ROOT_DIR}/remote/stage3.2

# initial checks
initial_checks() {
	if [ ! -d ${STAGE32_DIR} ];
	then
		echo "No stage3.2 directory found. Please run \"./mltk tools build\" first."
		exit 1
	fi

	if [ ! -e ${STAGE32_DIR}/openslx/bin/busybox ];
	then
		echo "Busybox not found, run 'setup_tools busybox' first."
		exit 1
	fi
	# shouldn't squashfs-tools be automatically installed as we need them nevertheless!?
	# what if it is already on the machine? faster to check with which than the apt-get check?
	if [ -z $(which mksquashfs) ];
	then
		echo "mksquashfs not found, please install squashfs-tools first."
		exit 1
	fi
	#check for kernel modules, if not present copy from system
	if [ ! -d ${STAGE32_DIR}/lib/modules ];
	then
		echo "Couldn't find kernel modules in stage3.2."
		echo "Copying modules for kernel $(uname -r)..."
		mkdir -p ${STAGE32_DIR}/lib/modules
		cp -r /lib/modules/$(uname -r) ${STAGE32_DIR}/lib/modules/
	fi

	# TODO: check for aufs and squaskfs modules
}

generate_rootfs() {

	# produce stage3.1
	[ ! -d ${STAGE31_DIR} ] && mkdir -p ${STAGE31_DIR}

	# create basic directory structure
	mkdir -p ${STAGE31_DIR}/{bin,dev,proc,run,lib/modules,etc,mnt,sys}

	# copy device files from running system
	cp -a /dev/{console,kmsg,mem,null,tty,tty0,tty1,tty9,urandom,zero} \
		${STAGE31_DIR}/dev

	# copy busybox, its libs and static data to stage3.1
	cp -r ${STAGE32_DIR}/openslx/* ${STAGE31_STATIC_DIR}/* ${STAGE31_DIR}

	# fix for aufs & squashfs modules needed for stage 3.1
	cp /lib/modules/$(uname -r)/kernel/fs/squashfs/squashfs.ko ${STAGE31_DIR}/lib/modules/
	cp /lib/modules/$(uname -r)/kernel/ubuntu/aufs/aufs.ko ${STAGE31_DIR}/lib/modules/

	# fetch the libraries needed for busybox
	BASICLIBS=""
	for i in $(ldd ${STAGE31_DIR}/bin/busybox);
	do
		if [ $(echo $i | grep '^/' | grep -c ld) -eq 1 \
		-o  $(echo $i | grep '^/' | grep -c libc.so) -eq 1 ];
        	then
	                BASICLIBS="$BASICLIBS $i $(readlink -f "$i")"
        	fi	
	done
	(tar cpv $BASICLIBS | tar xpv -C ${STAGE31_DIR}) &>/dev/null

}

generate_squashfs() {

	# finalize the initramfs target
	[ -e ${STAGE31_DIR}/mnt/openslx.sqfs ] && rm ${STAGE31_DIR}/mnt/openslx.sqfs 

	mksquashfs ${STAGE32_DIR} ${STAGE31_DIR}/mnt/openslx.sqfs -comp xz -b 1M -no-recovery 2>/dev/null

}

generate_initramfs() {

	cd ${STAGE31_DIR}
	find . | cpio --format="newc" --create | gzip -9 > ${MODULE_DIR}/initramfs
	cd -  &>/dev/null
}

generate_stage31() {
	initial_checks
	generate_rootfs
	generate_squashfs
	generate_initramfs

	# TODO better kernel copy
	cp /boot/vmlinuz-$(uname -r) ${MODULE_DIR}/kernel
}

clean_core() {
	echo -n "Cleaning ${STAGE31_DIR}..."
	[ -d ${STAGE31_DIR} ] && rm -rf ${STAGE31_DIR}
	echo " done."
	echo -n "Cleaning ${MODULE_DIR}/initramfs..."
	[ -e ${MODULE_DIR}/initramfs ] && rm ${MODULE_DIR}/initramfs
	echo " done."
}