borg backup cron script

backup.sh

#!/bin/bash -e

if [[ $# < 2 ]]; then
  echo "usage: backup REPO check | list | PREFIX SRC [--force] [borg_opts]"
  exit
fi

if [[ "$USER" != "root" ]]; then
   exec sudo -H systemd-inhibit "$0" "$@"
fi

export LANGUAGE=C
export LC_ALL=C.UTF-8
export BORG_REPO="$1"
shift

if [[ "$1" = "check" ]]; then
  shift
  borg check $*
  exit
fi

if [[ "$1" = "list" ]]; then
  shift
  borg list $*
  exit
fi

PREFIX=$1
SRC=$2
shift 2
SNAP=$SRC/backup
REPOHASH=$(echo "$SRC $BORG_REPO" |md5sum |cut -d" " -f1)
MARKER="$HOME/.cache/borg/$REPOHASH.marker"

if [[ "$1" = "--force" ]]; then
  shift
else
  on_ac_power || exit 1
  [[ ! -f $MARKER || "$(find $MARKER -mmin +240)" ]] || exit 2
fi

borg with-lock :: true

test ! -d $SNAP || btrfs su de $SNAP 
btrfs su sn -r $SRC $SNAP 

[ ! -t 1 ] || P="--progress"

cd $SNAP
borg info
borg create --stats --exclude-caches --exclude-if-present .nobackup --keep-exclude-tags $P $* ::$PREFIX-{now} .
borg prune  --stats --prefix $PREFIX --keep-last 3 --keep-within 7d --keep-daily 14 --keep-weekly 4 --keep-monthly 30 
borg list 

cd $SRC
btrfs su de $SNAP

echo "$SRC $BORG_REPO $(date -Is)" >$MARKER