kryo-discord-bot

A Discord bot to whitelist players on Velocity with multi-proxy support.

Report Bug · Request Feature

About the project

kryo-discord-whitelist is a whitelist where Discord users can add themselves by writing their username into a specific channel.

Prerequisites

kryo-discord-whitelist needs the following services to be installed and configured to function properly:

• MariaDB database
• RabbitMQ message broker

It is not recommended using the root user of the MariaDB server for kryo-discord-whitelist. Please create an extra database with an extra user that is limited to that database.

Setup

The installation and usage of kryo-discord-whitelist needs two separate modules, the Discord bot itself and a Velocity plugin. At the moment you need to build all JAR files yourself because we do not distribute prebuilt JARs.

Discord bot

The Discord bot needs access to the Discord API, therefore a token is needed. To get a token a Discord bot needs to be created in the Discord developer portal.

1. Goto the Discord Developer Portal and create a new Application.
2. Click on "Bot" in the sidemenu and add a new bot.
3. Click "Copy" next to the profile picture of the bot to copy the token.

With the generated token we can now start the discord bot. The discord bot needs two environment variables or Java start parameters to start.

Environment variable	Start parameter	Description
TOKEN	-DTOKEN	Discord Bot token
CONNECTION_STRING	-DCONNECTION_STRING	Connection String for connecting to the MariaDB database

A startup command could look like the following:

java -Xms128M -Xmx512M -DTOKEN=DISCORD_TOKEN -DCONNECTION_STRING=jdbc:mariadb://localhost:3306/database?user=user&password=password -JAR kryo-discord-whitelist-bot.JAR

Velocity plugin

To install the Velocity plugin just copy the JAR-file into the plugin directory.

Furthermore, the Velocity plugin needs some environment variables. Those can also be provided as startup parameters if the usage of environment variables is not possible.

Environment variable	Start parameter	Description
CONNECTION_STRING	-DCONNECTION_STRING	Connection String for connecting to the MariaDB database
RABBITMQ_ADDRESS	-DRABBITMQ_ADDRESS	Address and port of the RabbitMQ message broker
RABBITMQ_USERNAME	-DRABBITMQ_USERNAME	Username of the RabbitMQ message broker
RABBITMQ_PASSWORD	-DRABBITMQ_PASSWORD	Password of the RabbitMQ message broker

A startup command of the Velocity could look like the following:

java -Xms128M -Xmx1024M -XX:+UseG1GC -XX:G1HeapRegionSize=4M -XX:+UnlockExperimentalVMOptions -XX:+ParallelRefProcEnabled -XX:+AlwaysPreTouch -XX:MaxInlineLevel=15 -DCONNECTION_STRING=jdbc:mariadb://127.0.0.1:3306/database?user=user&password=password -DRABBITMQ_ADDRESS=127.0.0.1:5672 -DRABBITMQ_USERNAME=guest -DRABBITMQ_PASSWORD=guest -JAR velocity.JAR

Velocity Commands

Command	Permission	Description
/whitelist add <username>	whitelist	Add a player manually to the whitelist. Manually added players do not have to verify themselves via Discord.
/whitelist remove <username>	whitelist	Remove a player from the whitelist. If the player is online during the command execution the player gets kicked. This is also applicable if the player is on another proxy.

Development

Building

kryo-discord-whitelist is built with Gradle. We recommend using the included wrapper script (./gradlew) to ensure you use the same Gradle version as we do.

To build production-ready JAR files it is sufficient to run ./gradlew shadowJAR. You can find the JAR files in ./module-name/build/libs/*-all.JAR.

Testing

kryo-discord-whitelist uses JUnit 5 and Mockito for testing.

To run all tests just execute ./gradlew test