borg-create.sh

#/bin/bash

# encrypted USB stick by uuid
UUID=a20ec820-de7d-40ec-ac29-4595a10c38e7
PASS=xxxxxxxx
EXCLUDE=$HOME/.config/borg/exclude.list

# helpers
info() { notify-send "$*"; }
trap 'echo $( date ) Backup interrupted >&2; disk_unmount; exit 2' INT TERM

disk_mount() {
  udisksctl unlock \
    --key-file=<(echo -n "$PASS") \
    --block-device=/dev/disk/by-uuid/$UUID && \
  udisksctl mount \
    --block-device=/dev/mapper/luks-$UUID
}

disk_unmount() {
  udisksctl unmount \
    --block-device=/dev/mapper/luks-$UUID && \
  udisksctl lock \
    --block-device=/dev/disk/by-uuid/$UUID
}

# main
info "Starting backup"
disk_mount
export BORG_REPO=$(ls -d1 /run/media/$USER/*/borg-backup 2> /dev/null | head)

if [ ! -d "$BORG_REPO" ] ; then
  info "Borg repository is unavailable"
  exit 2
fi

borg create \
  --stats --show-rc \
  --exclude-from $EXCLUDE \
  ::'{hostname}-{now}' \
  $HOME

backup_exit=$?

borg prune \
  --stats --show-rc \
  --prefix '{hostname}-' \
  --save-space --keep-daily 7

prune_exit=$?

# use highest exit code as global exit code
global_exit=$(( backup_exit > prune_exit ? backup_exit : prune_exit ))

if [ ${global_exit} -eq 0 ]; then
  info "Backup and Prune finished successfully"
elif [ ${global_exit} -eq 1 ]; then
  info "Backup and/or Prune finished with warnings"
else
  info "Backup and/or Prune finished with errors"
fi

disk_unmount

exit ${global_exit}