Script to create a bootable system-stick out of a borg backup. <3 EFI

howard-stick.sh

#!/bin/bash

if [ -z "$1" ]; then
	echo "Usage: $0 <device> [borg repository]" >&2
	echo "WARNING: <device> will receive a new partition table and be erased completely" >&2
	exit 2
fi

if [ -e /dev/disk/by-partlabel/howard-esp -o -e /dev/disk/by-partlabel/howard-root ]; then
	echo "Failure: Partlabels howard-esp and/or howard-root already taken." >&2
	exit 3
fi

REPO="borg@backup.prauscher.de:howard"
[ -n "$2" ] && REPO="$2"

export BORG_PASSPHRASE="ARE-YOU-SERIOUS?!"
export BORG_RSH="ssh -i ~prauscher/.ssh/id_ed25519"

# Create Partition layout
parted --script "$1" -a optimal \
	mklabel gpt \
	mkpart howard-esp fat32 1MiB 538MiB \
	mkpart howard-root ext4 538MiB 100% \
	set 1 esp on

# wait for the devices to be ready
sleep 2

# Create partitions
# specify uuids for grub (mainly), fstab could use PARTLABEL=
mkfs.vfat -i 3E9CF97B /dev/disk/by-partlabel/howard-esp
mkfs.ext4 -U a9b3c40f-69a5-471d-a2cc-2055435e4f07 /dev/disk/by-partlabel/howard-root

trap "umount -R /mnt" EXIT

# Mount partitions
mount /dev/disk/by-partlabel/howard-root /mnt
mkdir -p /mnt/boot/efi
mount /dev/disk/by-partlabel/howard-esp /mnt/boot/efi

# create temporary folders not contained in the backup (excludes)
mkdir -p /mnt/tmp /mnt/var/tmp /mnt/dev /mnt/proc /mnt/sys /mnt/run /mnt/mnt /mnt/media /mnt/host
chmod +t /tmp
chmod +t /var/tmp

# get latest
ARCHIVE=$(borg list --short --last 1 "$REPO")

echo "Restoring from archive $REPO::$ARCHIVE"

# restore files
cd /mnt
borg extract --list --numeric-owner --exclude pp:host "$REPO::$ARCHIVE"

# copy bootloader
[ -d /mnt/boot/efi/EFI/boot ] || mkdir -p /mnt/boot/efi/EFI/boot
cp /mnt/boot/efi/EFI/debian/grubx64.efi /mnt/boot/efi/EFI/boot/grubx64.efi
cp /mnt/boot/efi/EFI/debian/shimx64.efi /mnt/boot/efi/EFI/boot/bootx64.efi

# wait for copy process to be done
sync
sleep 2

# unmount partitions is done in trap