#!/bin/bash

# This script is used by the CRON Daemon to check backups for consistency
# and optionally integrity via the Restic backup utility


# Load restic variables
source /etc/restic.d/backblaze.conf

# WARNING: Checking the backup integrity can be a costly procedure when using
# cloud data storage. This is because in order to verify integrity we must
# download the blobs and verify them. If the cloud storage provider charges
# more for download than upload (e.g, Cold Storage Plan) this can rack up
# expenses very quickly.
#
# Thankfully this does not need to be done very often BUT IT STILL NEEDS TO
# BE DONE. You wouldn't want to have your backups not working when you
# actually need to restore something would you? This does not normally need
# to be done very often, but if you would rather have the checks
# only perform consistency checking, not integrity checks you can remove
# the '--read-data' from the command.

# NOTE: When repositories get fairly large checking them can generate large
# cache directories. It can also take a very long time to complete. Because
# of this we split the operation into 255 parts that run individually.

# Check backup repository consistency (and integrity if --read-data is used)
counter=1
while [ "$counter" -le 255 ] ; do
	restic check \
		"$RESTIC_COMMON_OPTS" \
		--read-data-subset="$counter""/""255" 
	((counter++))
done