live-snapshot-auto1.sh

#!/usr/bin/env bash
#
# live-snapshot-auto1.sh

set -x

# Source system needs live-boot* and live-config* 
# Probably does not need refractasnapshot, isolinux, xorriso. Not sure about squashfs-tools.
# 


work_dir="$(pwd)"

# mountpoint or directory containing the system to be copied
# DO NOT USE TRAILING SLASHES HERE
source_system=			

# the rsync copy of the filesystem
myfs="${work_dir}/myfs"

# rsync excludes file					
snapshot_excludes="live-snapshot_exclude.list"			

# source of the isolinux files
# use the iso dir that comes with refractasnapshot
# or point this to your custom iso dir
iso_dir="/usr/lib/refractasnapshot/iso"				# 

# where to put the finished iso
snapshot_dir="$work_dir" 

# name for the iso file, including .iso extension
filename="snapshot_$(date +%Y%m%d_%H%M).iso"				

# kernel and initrd to use in the iso
kernel_image="$source_system"/vmlinuz
initrd_image="$source_system"/boot/initrd.img-3.16.0-4-686-pae		####### symlink doesn't work in mounted system

make_isohybrid="yes"



# Record errors in a logfile.
error_log="$(pwd)/errors_live-snapshot.log"
exec 2>"$error_log"


#copy stuff from the source system to the snapshot.

copy_isolinux () {

if [[ -f /usr/lib/ISOLINUX/isolinux.bin ]] ; then
	isolinuxbin="/usr/lib/ISOLINUX/isolinux.bin"
elif [[ -f /usr/lib/syslinux/isolinux.bin ]] ; then
	isolinuxbin="/usr/lib/syslinux/isolinux.bin"
else
	echo "You need to install the isolinux package."
	exit 1
fi

### Might need to add chain.c32 to this list of copied files:

if [[ -f /usr/lib/syslinux/modules/bios/vesamenu.c32 ]] ; then
	vesamenu="/usr/lib/syslinux/modules/bios/vesamenu.c32"
	rsync -a /usr/lib/syslinux/modules/bios/chain.c32 "$iso_dir"/isolinux/
	rsync -a /usr/lib/syslinux/modules/bios/ldlinux.c32 "$iso_dir"/isolinux/
	rsync -a /usr/lib/syslinux/modules/bios/libcom32.c32 "$iso_dir"/isolinux/
	rsync -a /usr/lib/syslinux/modules/bios/libutil.c32 "$iso_dir"/isolinux/
else
	vesamenu="/usr/lib/syslinux/vesamenu.c32"
fi
rsync -a "$isolinuxbin" "$iso_dir"/isolinux/
rsync -a "$vesamenu" "$iso_dir"/isolinux/

}


# Let iso/, vmlinuz and initrd.img get copied, even if work_dir was saved,
# in case they have changed, unless $nocopy = yes.
copy_kernel () {

rsync -a "$iso_dir"/ "$work_dir"/iso/
cp "$kernel_image" "$work_dir"/iso/live/
cp "$initrd_image" "$work_dir"/iso/live/initrd.img		########### rename initrd so it matches boot menu

}


# rsync exclude list needs items prepended with "$source_system"/
copy_filesystem () {

	rsync -av "$source_system"/  "$myfs"/ --exclude-from="$snapshot_excludes" --delete-before --delete-excluded

}


### THE WORK STARTS HERE ###

cd "$work_dir"

copy_isolinux
copy_kernel
copy_filesystem


# Truncate logs, remove archived logs.
find myfs/var/log -name "*gz" -print0 | xargs -0r rm -f
find myfs/var/log/ -type f -exec truncate -s 0 {} \;
# add static links in /dev


# /etc/fstab should exist, even if it's empty,
# to prevent error messages at boot
touch "$work_dir"/myfs/etc/fstab

# Blank out systemd machine id. If it does not exist, systemd-journald
# will fail, but if it exists and is empty, systemd will automatically
# set up a new unique ID.

if [ -e "$work_dir"/myfs/etc/machine-id ]
then
	rm -f "$work_dir"/myfs/etc/machine-id
	: > "$work_dir"/myfs/etc/machine-id
fi

# add some basic files to /dev
mknod -m 622 "$work_dir"/myfs/dev/console c 5 1
mknod -m 666 "$work_dir"/myfs/dev/null c 1 3
mknod -m 666 "$work_dir"/myfs/dev/zero c 1 5
mknod -m 666 "$work_dir"/myfs/dev/ptmx c 5 2
mknod -m 666 "$work_dir"/myfs/dev/tty c 5 0
mknod -m 444 "$work_dir"/myfs/dev/random c 1 8
mknod -m 444 "$work_dir"/myfs/dev/urandom c 1 9
chown -v root:tty "$work_dir"/myfs/dev/{console,ptmx,tty}

ln -sv /proc/self/fd "$work_dir"/myfs/dev/fd
ln -sv /proc/self/fd/0 "$work_dir"/myfs/dev/stdin
ln -sv /proc/self/fd/1 "$work_dir"/myfs/dev/stdout
ln -sv /proc/self/fd/2 "$work_dir"/myfs/dev/stderr
ln -sv /proc/kcore "$work_dir"/myfs/dev/core
ln -sv /run/shm "$work_dir"/myfs/dev/shm
mkdir -v "$work_dir"/myfs/dev/pts



mksquashfs "$myfs"/ iso/live/filesystem.squashfs -comp xz -noappend

make_iso () {

# If isohdpfx.bin gets moved again, maybe use:   isohdpfx=$(find /usr/lib/ -name isohdpfx.bin)
    if [[ $make_isohybrid = "yes" ]]; then
       if [[ -f /usr/lib/syslinux/mbr/isohdpfx.bin ]] ; then
          isohybrid_opt="-isohybrid-mbr /usr/lib/syslinux/mbr/isohdpfx.bin"
       elif [[ -f /usr/lib/syslinux/isohdpfx.bin ]] ; then
                    isohybrid_opt="-isohybrid-mbr /usr/lib/syslinux/isohdpfx.bin"
       elif [[ -f /usr/lib/ISOLINUX/isohdpfx.bin ]] ; then
          isohybrid_opt="-isohybrid-mbr /usr/lib/ISOLINUX/isohdpfx.bin"
		else
			echo "Can't create isohybrid.  File: isohdpfx.bin not found. The resulting image will be a standard iso file."
		fi
	fi

 
xorriso -as mkisofs -r -J -joliet-long -l ${isohybrid_opt} \
    -partition_offset 16 -V "snapshot-live-cd"  -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot \
    -boot-load-size 4 -boot-info-table -o "$snapshot_dir"/"$filename" iso/

}

make_iso

### md5sum, sha256sum, gpg-sign "$filename"
		md5sum "$snapshot_dir"/"$filename" > "$snapshot_dir"/"$filename".md5
		
		chown 1000:1000 "$snapshot_dir"/"$filename"*

exit 0