feature RQ -- Bedrock Worlds backup

[MattrCoUk]

My server's been been working great on my MacMini, thanks to this repo! With few friends we've started building a village, with people connecting at various times. It would be a shame if all wonderful builds they create got destroyed.

Bedrock server has the built-in backup functionality which works as I tested. But it is far from automated.

It involves tying in the server console save hold, save query, copy world files and save resume.

I was wondering if it would be somehow possible to automate it. Run with an interval. Perhaps a shell script in the container sending mentioned commands to the Bedrock console and then copying files to an external volume.

I could work on this but don’t have clue where to start...

Maybe I could use something like Expect?

[itzg]

I agree that it would be really nice to automate that process, but yes it would need to be something that could inspect the save query and react accordingly.

Right now the server process is wrapped by this helper tool I developed
https://github.com/itzg/entrypoint-demoter

That tool is currently generic to any type of containerized process; however, I'm thinking I need to spin off a bedrock server specific version of that. With that it could expose bedrock-specific operations such as doing a backup.

Enhancing that Go-based tool might have been more than what you were offering, but that's where I would see the enhancement happening. I have been wanting to expose console access via a web API anyway, so I might prioritize working on both of these changes soon myself.

[MattrCoUk]

Great stuff! thanks!

[MattrCoUk]

btw.. If you play MC yourself it would be a pleasure to invite u to our lil server, it’s great fun. Let me know!

[itzg]

I'm kind of a solitary LAN-server player, but yeah I should really get out there in the "world" ;) Shoot me your server address in email (itzgeoff@gmail.com) or DM me on Discord and I'll jump on sometime.

[MattrCoUk]

I’ve created a little script that seems to be working fine on 1.16.1, thought I share.
It requires expect and can be run with cron or lunchd every half hour or so.
(You might need to verify your docker path by running which docker)

#!/usr/bin/expect --

set world_dir <dirs>/worlds
set docker_container <container name>
set world_name <world name>
set backup_dest “<dirs>"
set timestamp [timestamp -format {%Y-%m-%d--%H-%M}]
set world_compress_timeout 240
set world_arch_mv_timeout 30
# log_file <path>backup-world.log  # the log file might get large quickly!

spawn /usr/local/bin/docker attach --detach-keys=Q $docker_container
expect "DEBU*”


while true {
  
  send "save hold\r"
  expect "Saving...*" { break }
  expect "The command is already running*" { break }
}
sleep 1

while true {
  
  send "save query\r"
  expect "Data saved.*" { break }
}

while true {
  
  send "Q"
  expect eof { break }
}

spawn bash
send "cd \"$world_dir\"\r"
expect "*$ "

set timeout $world_compress_timeout
send "tar -zcf $world_name.$timestamp.tgz $world_name\r"
expect "*$ "

set timeout $world_arch_mv_timeout
send "mv $world_name.$timestamp.tgz \"$backup_dest\"\r"
expect "*$ "
send "exit\r"
expect eof

set timeout 10
spawn /usr/local/bin/docker attach --detach-keys=Q $docker_container
expect "DEBU*"
while true {
  
  send "save resume\r"
  expect "Changes to the level are resumed.*" { break }
}

while true {
  
  send "Q"
  expect eof { break }
}
exit

[DocBrown101]

Here is my simple backup-script. Works since one year!

#!/bin/bash
docker-compose -f "/home/daniel/dropbox/data/docker/3-minecraft/docker-compose.yml" down

_day="$(date +'%A')"
_file="minecraft-data-${_day}.tar"
_path="/home/daniel/dropbox/data/docker-backup/${_file}"

tar -P -cf ${_path} --exclude='bedrock_server*' /home/daniel/docker-data/minecraft --overwrite

docker-compose -f "/home/daniel/dropbox/data/docker/3-minecraft/docker-compose.yml" up -d --build

[wedgef5]

I'm sort of new to Minecraft, and I'm investigating setting up a Bedrock server to run on our LAN for our kids and a few of their friends. I don't have a clear understanding of the process of backing up worlds. When you speak of commands like "save hold" and "save query", is that to facilitate backing up a running server? Would it be an acceptable workaround to periodically stop the server, make a backup of the worlds folder and then start the server, assuming this is done when the server is definitely not in use?

[itzg]

@wedgef5 yes, doing the backup while the server is stopped would be a great alternative.

[Kaiede]

Just wanted to comment that I've been playing around with a tool that can do these sort of backups. I started by creating a CLI tool I could run via systemd on the docker host, and I recently containerized it with a bit of help from reading through the docker-mc-backup scripts. It is able to backup a running server just fine, but it does require access to the host's docker.sock file in order to accomplish this.

It's a bit rough around the edges at the moment because it's not what I'd consider fully containerized and so the config file contains values it doesn't actually need, but it is what I've been using for about 3 weeks now (via systemd) and the last few days (via docker) on my own two-server host.

Docker Hub: https://hub.docker.com/r/kaiede/minecraft-bedrock-backup
GitHub: https://github.com/Kaiede/docker-minecraft-bedrock-backup
CLI Tool: https://github.com/Kaiede/BedrockifierCLI

[itzg]

Awesome. @Kaiede when you're ready for it, I would be happy to add a "Backups solutions" section to the README that links to your image.

[Kaiede]

I've done the cleanup I want to do around the configuration. I think I've managed to get it to the "minimum viable product" state that I'm happy with, and the changes have shown to be stable on my home server. So feel free to add the reference.

Mostly worried that the documentation needs some revision, but at this point, will have to see where folks get hung up on configuring things.

[itzg]

There it is:

https://github.com/itzg/docker-minecraft-bedrock-server#solutions-for-backing-up-data

[MattrCoUk]

This is awesome. I’m just wondering how that compares performance-wise vs just making dumps of a world via MC server’s CLI and just tar-ing them? My server runs on a quite low-RAM machine stretched up to limit so wondering if another docker container would take-up much resources.

[itzg]

Containers don't add any memory overhead, so @Kaiede 's backup container would only occupy the memory for the bash script to sleep most of the time. Since the tool is compiled from Swift, I'm guessing it has very low memory footprint for those moments it runs.