#!/bin/bash
# Local backup script, adapted from https://webworxshop.com/centralised-backups-with-restic-and-rsync/
# Place in /usr/sbin/backup.sh
# Enable with `systemctl enable backup.timer`
# Check status with `systemctl status backup.service`
set -e

# Check variables
if [ -z "$BACKUP_DEST" ]; then 
  echo "BACKUP_DEST must be set"
  exit 1
fi

if [ -z "$RESTIC_REPOSITORY" ]; then 
  echo "RESTIC_REPOSITORY must be set"
  exit 1
fi

if [ -z "$RESTIC_PASSWORD_FILE" ]; then 
  echo "RESTIC_PASSWORD_FILE must be set"
  exit 1
fi

if [ -Z "$BACKUP_DIRS" ]; then
  echo "BACKUP_DIRS must be set"
  exit 1
fi

if [! -Z "$EXCLUDE_FILE" ]; then
  EXCLUDES="--exclude-from=$EXCLUDE_FILE"
fi


# Split dirs using semicolons
DIRS=$(echo $BACKUP_DIRS | tr ";" "\n")


function do_rsync() {

    # Write start info to log file
    echo "Starting rsync backup job $1 to $BACKUP_DEST$1 at $(date '+%Y-%m-%d %H:%M:%S')..."

    # Ensure backup directory exists
    mkdir -p $BACKUP_DEST$1

    # Execute rsync
    /usr/bin/rsync -aP --delete $EXCLUDES $1 $BACKUP_DEST

    # Write end-info to log file
    echo "Rsync job finished at $(date '+%Y-%m-%d %H:%M:%S')."

    echo "Done"
}

echo "Starting rsync clone"

for D in $DIRS; do
  do_rsync $D
done

# copy apt list
dpkg --get-selections > $BACKUP_DEST/packages.list


echo "Starting restic backup"

# Check database
restic check


# Execute backups
for D in $DIRS; do
  restic backup $BACKUP_DEST/$D
done


# Clean up old snapshots
restic forget -d 7 -w 4 -m 6 -y 2


# Re-check the database
restic check