labsync/imagesync.sh

#!/bin/sh

case $1 in
prereqs)
	##
	# GET EXECUTED WHEN BUILDING INITRAMFS
	#
	. /usr/share/initramfs-tools/hook-functions
	copy_exec /usr/bin/aria2c
	copy_exec /sbin/sfdisk
	copy_exec /sbin/mke2fs
	copy_exec /sbin/e2fsck
	copy_file cert /etc/ssl/certs/ca-certificates.crt
        exit 0
        ;;
esac

##
# FUNCTION DEFINITIONS
##

print_waiting() {
	echo -en "\033[36m${1}... \033[0m"
}

print_warning() {
	echo -e "\n\033[31mWARNING: ${1}\033[0m"
}

print_done() {
	echo -e "\033[32mdone.\033[0m"
}

error_fatal() {
	print_warning "$1; interrupting startup"
	while sleep 3600;do sleep 3600;done
}

##
# SHOW BRANDING
##

echo -e '
Starting
 ""#           #
   #     mmm   #mmm    mmm   m   m  m mm    mmm
   #    "   #  #" "#  #   "  "m m"  #"  #  #"  "
   #    m"""#  #   #   """m   #m#   #   #  #
   "mm  "mm"#  ##m#"  "mmm"   "#    #   #  "#mm"
                              m"
                             ""
https://gitlab.jalr.de/fablab/initramfs
'

##
# READ CONFIGURATION PARAMETERS FROM KERNEL PARAMETERS
##

print_waiting "Reading configuration parameters"
set -- $(cat /proc/cmdline)
for x in "$@"; do
	case "$(echo $x | cut -d= -f1)" in
		disk)
		disk="$(echo $x | cut -d= -f2)"
		;;
		root)
		root="$(echo $x | cut -d= -f2)"
		;;
		partsize)
		partsize="$(echo $x | cut -d= -f2)"
		;;
		torrent)
		torrent="$(echo $x | cut -d= -f2)"
		;;
		qemu)
		qemu="$(echo $x | cut -d= -f2)"
		;;
	esac
done

# Check if mandatory parameters are missing

if [ -z "$disk" ];then
	error_fatal "The disk parameter is missing"
fi
if [ -z "$root" ];then
	error_fatal "The root parameter is missing"
fi
if [ -z "$partsize" ];then
	error_fatal "The partsize parameter is missing"
fi
if [ -z "$torrent" ];then
	error_fatal "The torrent parameter is missing"
fi
print_done

##
# PARTITIONING OF DISK
##

size_part_1=$(($partsize * 1024 * 1024 / 512))

parttable="label: dos
label-id: 0xdeadbeef
device: $disk
unit: sectors

$root : start=        2048, size=     $size_part_1, type=83"

readtable="$(sfdisk -d $disk)" # wtf? but it is needed

print_waiting "Checking partition tables"
if [ "$parttable" != "$readtable" ];then
	print_done
	print_waiting "Partition tables do not match; partitioning disk"
	rewrite_rootfs=true
sfdisk -q $disk << PARTTABLE
$parttable
PARTTABLE
	print_done
else
	print_done
fi

print_waiting "Checking root filesystem"
e2fsck -y $root &> /dev/null
fsck=$?
if [ "$fsck" != 0 ] && [ "$fsck" != 1 ] || [ "$rewrite_rootfs" == "true" ];then
	print_done
	print_waiting "Creating root filesystem"
	mke2fs -q -F -t ext4 $root
	print_done
else
	print_done
fi

##
# TEMPORARY NETWORK CONFIG (only for qemu)
##

if ! [ -z "$qemu" ];then
	print_waiting "Setting up temporary network config"
	ip addr add 10.2.2.2/24 dev ens3
	ip link set ens3 up
	print_done
else
	print_waiting "Setting up interfaces with DHCP"
	ipconfig all
	print_done
fi

##
# MOUNT TEMPORARY ROOTFS
##

print_waiting "Mounting temporary root filesystem"
mkdir -p /tmp_root
mount -t ext4 $root /tmp_root
cd /tmp_root
print_done

##
# DOWNLOAD FS IMAGE
##

print_waiting "Downloading root filesystem image"
# --allow-overwrite: do not rename the torrent file
# --check-integrity: verify downloaded file and do not complain about missing controll file
# --seed-time=0: do not wait until ratio 1, we seed when we’re booted
# --summary-interval=0: do not show summary while downloading
# --console-log-level=error: Only show errors
# --download-result=hide: Do not show download results
download=true
while [ "$download" == true ];do
	aria2c \
		--allow-overwrite \
		--check-integrity \
		--seed-time=0 \
		--summary-interval=0 \
		--console-log-level=error \
		--download-result=hide \
		$torrent 2>&1 | grep -v 'DHT routing table'
	if [ $? == 0 ];then
		download=false
	else
		rm rootfs.tar.gz rootfs.torrent
	fi
done
print_done

print_waiting "Comparing installed and remote image"
if [ -f /tmp_root/.build_uuid ];then
	cd /tmp
	tar xzf /tmp_root/rootfs.tar.gz .build_uuid
	if [ "$(cat .build_uuid)" == "$(cat /tmp_root/.build_uuid)" ];then
		sync=false
		print_done
	else
		sync=true
		print_done
		print_waiting "Deleting old filesystem"
		cd /tmp_root
		rm -rf $(tar tzf rootfs.tar.gz|grep '^[^/]*/$' )
		cd /tmp
		print_done
	fi
	rm .build_uuid
	cd /tmp_root
else
	sync=true
	print_done
fi

if [ "$sync" == "true" ];then
	print_waiting "Extracting root filesystem image"
	tar xzf rootfs.tar.gz
	print_done
fi

##
# UNMOUNT TEMPORARY ROOTFS
##

print_waiting "Unmounting temporary root filesystem"
cd /
umount /tmp_root
print_done