Minecraft server backup script.

minecraft_server_backup.sh

#!/usr/bin/sh
# minecraft_server_backup.sh
# Minecraft server backup script.

# Before using this script, make sure that you install
# Minecraft server according to this guide:
# https://www.lessavin.ru/blog/minecraft-server.html

# Configuration.
# Minecraft server directory.
MINECRAFT_DIRECTORY="/srv/minecraft-server"
# Backup directory.
BACKUP_DIRECTORY="$HOME/Documents/archive"
# Backup filename date format.
# ISO 8601 by default.
DATE_FORMAT="%Y-%m-%d"

set -e

# Directory setup.
mkdir -p "$MINECRAFT_DIRECTORY" "$BACKUP_DIRECTORY"

# According to Minecraft Wikipedia:
# https://minecraft.wiki/w/Tutorial:Server_maintenance

# Save the world before closing server.
mcrcon save-all

# Close Minecraft server.
sudo systemctl stop minecraft-server

# Make sure that server is fully stopped.
until ! systemctl is-active --quiet minecraft-server
do
    sleep 5
done

# Sometimes Minecraft server creates .dat files with wrong permissions.
# This line allows reading them.
sudo chmod 660 "$MINECRAFT_DIRECTORY/world/*.dat" \
	"$MINECRAFT_DIRECTORY/world/*.dat_old" \
	"$MINECRAFT_DIRECTORY/world/playerdata/*.dat" \
	"$MINECRAFT_DIRECTORY/world/playerdata/*.dat_old"

backup="$BACKUP_DIRECTORY/minecraft-server_$(date +$DATE_FORMAT).tar"

# Creating archive in backup directory.
tar cfv "$backup" "$MINECRAFT_DIRECTORY"

# Now start the server.
sudo systemctl start minecraft-server

# Compress archive.
# lrzip is the best way to compress large-scale data.
lrzip --delete "$backup"

backup="$backup.lrz"

# Create archive checksum.
cd "$BACKUP_DIRECTORY"
sha256sum "$backup" > "$backup".sha256