bundlewrap/bundles/zfs/files/backup-pre-hook

#!/bin/bash

errors=0

run-parts --exit-on-error -- /etc/zfs-snapshot-backup-pre.d || errors=1


% for dataset in sorted(node.metadata.get('zfs/filesystems_with_backup_snapshots')):
mountpoint="/mnt/backup-snapshot${node.metadata['zfs']['datasets'][dataset]['mountpoint']}"

if findmnt "$mountpoint" >/dev/null
then
    umount -R "$mountpoint" || errors=1
fi

if zfs get type "${dataset}@snapshot-backup" >/dev/null 2>&1
then
    zfs destroy "${dataset}@snapshot-backup" || errors=1
fi

zfs snapshot "${dataset}@snapshot-backup" || errors=1

mkdir -p "$mountpoint" || errors=1
mount -t zfs "${dataset}@snapshot-backup" "$mountpoint" || errors=1


% endfor
run-parts --exit-on-error -- /etc/zfs-snapshot-backup-post.d || errors=1

if (( errors ))
then
    # We can't use 'set -e' in here, because this could result in services
    # not getting started, if they need to get stopped before creating a
    # consistent backup snapshot.
    exit 1
fi