In summary, I use my ratcraft script to manage a Minecraft server in the "cloud".
Virtual hardware
I have a Linode shared virtual instance with the following specs: 4 GB RAM, 2 Cores, 80 GB SSD, at $20 per month. Cheaper instances may work, but we’ve had no problem with four or more people playing on this instance.
Hosting on an in-house computer works great (and would be cheaper after about a year or so), but having the "cloud" instance is so much easier to manage and getting friends outside of the house connected is 100% easier.
The instance runs Slackware Linux and I do all server management at the command line through SSH.
I also gave it a DNS subdomain so it’s real easy to tell friends how to access it.
Minecraft Server
We’ve experimented with mods (and creating them), so we’ve run Spigot servers locally. But on the always-on family server, we run the so-called "vanilla" Minecraft server (Java Edition).
Launching the server
The server is a Java executable that needs to be kept running in a process.
I’ve opted to manage the process with the GNU terminal multiplexer screen.
The start command would look something like this:
# screen -S session_name -dm bash -c "cd worlddir; java -Xms512M -Xmx1024M -XX:ParallelGCThreads=1 -jar serverxxx.jar nogui"
Obviously I’m not going to type that more than once, so I wrote a little application (a wee Bash script) to manage this for me called ratcraft.
It’s about 130 lines of Bash and has a handful of commands:
# Usage: ratcraft ( start | stop | status | backup | watch | cmd <command> )
Server upgrades
The Minecraft clients automatically update to the latest version as soon as it’s out.
Getting the latest server to match is as simple as grabbing the tarball link from minecraft.net/download/server and downloading it on the host:
# wget https://launcher.mojang.com/v1/objects/1b55...73ced/server.jar # mv server.jar minecraft_server.1.16.5.jar # ls bin/ minecraft_server.1.16.1.jar minecraft_server.1.16.4.jar old_server/ mcserver/ minecraft_server.1.16.2.jar minecraft_server.1.16.5.jar minecraft_server.1.15.2.jar minecraft_server.1.16.3.jar minecraft_server.1.16.jar
UPDATE: I no longer manually rename the server to the version number and keep the old ones around.
Instead, I let the downloaded server.jar overwrite the previous. Saves a step and I haven’t had
any need to downgrade (yet).
So I no longer do this step: manually edit the ratcraft script to update the server version:
jar=~/minecraft_server.1.16.5.jar
Then I just restart (stop and start) the server with ratcraft:
# ratcraft stop Stopping server... [20:03:24] [Server thread/INFO]: ThreadedAnvilChunkStorage (world2): All chunks are saved [20:03:24] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM-1): All chunks are saved [20:03:24] [Server thread/INFO]: ThreadedAnvilChunkStorage (DIM1): All chunks are saved Server stopped # ratcraft start Starting server... To see how it's going, try: ratcraft watch
In a few moments, the server is ready for the updated clients.
It’s not a commercial-grade solution, but it’s:
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Simple enough for me to understand when I come back to it every couple months
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Automated enough to not be a total pain to use
Backups
The ratcraft script has a backup feature.
I call it daily via a cron job in Slackware’s /etc/cron.daily directory.
The script simply calls:
/theuserdir/bin/ratcraft backup
The backup tells the Minecraft server to stop saving, makes a .tgz with tar -cpvzf of the "world" directory and saves it in a "backups" directory.
The backup command also performs simple backup rotation so the server doesn’t fill up. Occasionally we might want to save an important epoch in our world, so I just rename one of the backups so it doesn’t get removed in the rotation.
Getting/Upgrading the JDK
Maybe you can just use the java executable on your system and update with a package manager.
But in my universe, it’s a little more manual.
The Minecraft server upgrades seem to require newer and newer versions of the JVM. I don’t keep up with the Java world at all any more, but it looks like the current best place to get the JVM is:
I don’t see where you can get just the JRE (runtime environment with JVM, which is all that should be needed to run the Minecraft server). But not a big deal. The JDK is just a bigger download since it’s a superset of JRE plus compiler and libraries, etc.
The last time I did this looked like this:
$ wget wget https://download.java.net/...linux-x64_bin.tar.gz
$ tar -xf openjdk-17.0.1_linux-x64_bin.tar.gz
$ jdk-17.0.1/bin/java --version
openjdk 17.0.1 2021-10-19
OpenJDK Runtime Environment (build 17.0.1+12-39)
OpenJDK 64-Bit Server VM (build 17.0.1+12-39, mixed mode, sharing)
$ vim bin/ratcraft
start_cmd="<new path to java> -Xms512M blah blah..."
Hope that helps!