Hetzner backup hook to mount Hetzner backup space

proxmox-backup-hook.sh

#!/bin/bash
# vzdump hook script that handles mounting of [Hetzner] backup space
# [over SFTP] and then mounting an FS image stored there.
# After backup is done backup image is remounted to ensure data synced.
# Relies on /etc/fstab entries for backup mount points and pub key auth
# for SFTP.
#
# Corresponding fstab enties:
# uXXXXXX@uXXXXXX.your-backup.de: /mnt/backup-space fuse.sshfs defaults,noauto,allow_root,_netdev 0 0
# /mnt/backup-space/image         /mnt/backup       ext4      noauto,defaults,loop                0 0

PHASE="$1"; shift
MODE="$1"; shift
VMID="$1"; shift
## other available variables
#DUMPDIR
#HOSTNAME
#TARFILE
#LOGFILE

if [ -n "$DEBUG" ]
then
	echo " =============="
	echo "PHASE ${PHASE}"
	echo "MODE ${MODE}"
	echo "VMID ${VMID}"
	echo "DUMPDIR ${DUMPDIR}"
	echo "HOSTNAME ${HOSTNAME}"
	echo "TARFILE ${TARFILE}"
	echo "LOGFILE ${LOGFILE}"
	echo " =============="
fi

case $PHASE in
job-start)
	echo "Making sure backup space and image are mounted"
	mount -v /mnt/backup-space
	mount -v /mnt/backup
	# give FS some extra time
	sleep 2
	;;

backup-end|backup-abort)
	echo "$(date) Force sync to backup image fs..."
	umount -v /mnt/backup
	mount -v /mnt/backup
	echo "$(date) done"
	;;

job-end)
	echo "Unmount backup storage"
	umount -v /mnt/backup
	umount -v /mnt/backup-space
	;;

*)
	exit 0
	;;
esac

exit 0

based off http://www.blunix.org/howto-use-hetzner-backup-space-with-rsync/ and https://www.dim13.org/Backup-Proxmox-Containers-to-FTP

this way differential backups from https://ayufan.eu/projects/proxmox-ve-differential-backups/ work fine