papermc-backup.crontab

# m h  dom mon dow   command
*/5 *    *   *   *   /home/jmkim/papermc-backup.sh

papermc-backup.sh

#!/usr/bin/env bash

set -e

PAPER_DIR='/home/jmkim/papermc'
WORLDS_DIR=('world' 'world_nether' 'world_the_end')
BACKUP_DIR='/home/jmkim/papermc-backups'

mkdir -p "$BACKUP_DIR"

latest_backup="$(ls -1tr "$BACKUP_DIR" | tail -n 1)"
if [[ -n "$latest_backup" ]]; then
  latest_md5sum="$(md5sum "$BACKUP_DIR/$latest_backup" | awk '{ print $1 }')"
fi

newtar_tmp="$(mktemp)"
tar -Jcf "$newtar_tmp" -C "$PAPER_DIR" "${WORLDS_DIR[@]}"
newtar_md5sum="$(md5sum "$newtar_tmp" | awk '{ print $1 }')"

if [[ "$latest_md5sum" != "$newtar_md5sum" ]]; then
  mv "$newtar_tmp" "$BACKUP_DIR/$EPOCHREALTIME.tar.xz"
else
  rm "$newtar_tmp"
fi