Heroku Minecraft Buildpack

This is a Heroku Buildpack for running a Minecraft server in a dyno.

Usage

Create a free ngrok account and copy your Auth token. Then create a new Git project with a eula.txt file:

$ echo 'eula=true' > eula.txt
$ git init
$ git add eula.txt
$ git commit -m "first commit"

Then, install the Heroku toolbelt. Create a Heroku app, set your ngrok token, and push:

$ APP_NAME=heroku-minecraft
$ heroku create $APP_NAME
$ heroku buildpacks:add --app=$APP_NAME heroku/python
$ heroku buildpacks:add --app=$APP_NAME heroku/jvm
$ heroku buildpacks:add --app=$APP_NAME jameswberry/minecraft
$ heroku config:set --app=$APP_NAME NGROK_API_TOKEN="xxxxx"
$ git push heroku master

Finally, open the app:

$ heroku open

This will display the ngrok logs, which will contain the name of the server (really it's a proxy, but whatever):

Server available at: 0.tcp.ngrok.io:17003

Copy the 0.tcp.ngrok.io:17003 part, and paste it into your local Minecraft app as the server name.

Syncing to S3

The Heroku filesystem is ephemeral, which means files written to the file system will be destroyed when the server is restarted.

Minecraft keeps all of the data for the server in flat files on the file system. Thus, if you want to keep you world, you'll need to sync it to S3.

First, create an AWS account and an S3 bucket. Then configure the bucket and your AWS keys like this:

$ echo 's3cmd' > requirements.txt
$ git add requirements.txt
$ heroku config:set --app=$APP_NAME AWS_BUCKET=your-bucket-name
$ heroku config:set --app=$APP_NAME AWS_ACCESS_KEY=xxx
$ heroku config:set --app=$APP_NAME AWS_SECRET_KEY=xxx
$ git commit -m "S3 config redeploy"
$ git push heroku master

The buildpack will sync your world to the bucket every 60 seconds, but this is configurable by setting the AWS_SYNC_INTERVAL config var.

$ heroku config:set --app=$APP_NAME AWS_SYNC_INTERVAL=xxx
$ git commit -m "S3 sync interval update redeploy"
$ git push heroku master

Connecting to the server console

The Minecraft server runs inside a screen session. You can use Heroku Exec to connect to your server console.

Once you have Heroku Exec installed, you can connect to the console using

$ heroku ps:exec
Establishing credentials... done
Connecting to web.1 on ⬢ lovely-minecraft-2351...
$ screen -r minecraft

WARNING You are now connected to the Minecraft server. Use Ctrl-A Ctrl-D to exit the screen session. (If you hit Ctrl-C while in the session, you'll terminate the Minecraft server.)

Customizing

ngrok

You can customize additional ngrok settings throuigh the NGROK_OPTS config variable. For example:

$ heroku config:set --app=${APP_NAME} NGROK_OPTS="--remote-addr 9.tcp.ngrok.io:25565"
$ heroku restart
$ heroku open

NOTE The Mincraft Port Number will be automatically added to the end of the ngroc command.

Minecraft Port Number

You can choose the Minecraft port by setting the MINECRAFT_PORT like so:

$ heroku config:set --app=$APP_NAME MINECRAFT_PORT="99999"
$ git commit -m "redeploy"
$ git push heroku master

NOTE: Make sure to update your new port number in `server.properties'.

Minecraft Version

You can choose the Minecraft version by setting the MINECRAFT_VERSION like so:

$ heroku config:set MINECRAFT_VERSION="1.16.4"

Minecraft Server Configuration

You can also configure the server properties by creating a server.properties file in your project and adding it to Git. This is how you would set things like Creative mode and Hardcore difficulty. The various options available are described on the Minecraft Wiki.

You can add files such as banned-players.json, banned-ips.json, ops.json, whitelist.json to your Git repository and the Minecraft server will pick them up.

Minecraft Build: Forge

You can choose the Minecraft Forge build by setting the FORGE_VERSION like so:

$ heroku config:set FORGE_VERSION="1.16.4-35.1.37"

NOTE: Forge versions MUST include both the Server Version and the Build Version separated by a '-' dash/hyphen.

You can find a list of all available forge versions at the following URL: http://files.minecraftforge.net/maven/net/minecraftforge/forge/