DiscordModBot

A Discord bot that helps with managing a Discord server/guild.

The current purpose of this project is to provide services to the Fairy tail guild and Re: zero guild.

You are free to modify the code to make it work on your own guild, but right now no support will be offered. The plan is to make things less hard coded in the future where possible and make everything more configurable.

Configuration

Spring Boot configuration can be provided through application.properties, environment variables, or command-line args. For environment variables, convert property names to uppercase and replace ./- with _.

Required bot properties

These are bound from discord-mod-bot.* and the application will fail to start if they are missing.

Property	Environment Variable	Required	Description
discord-mod-bot.owner-id	DISCORD_MOD_BOT_OWNER_ID	Yes	Discord user ID for the bot owner (used for owner-only actions).
discord-mod-bot.bot-token	DISCORD_MOD_BOT_BOT_TOKEN	Yes	Discord bot token used to connect to the Discord gateway.

Default runtime properties

These defaults are defined in src/main/resources/application.properties.

Property	Default	Description
spring.profiles.active	production	Active Spring profile.
logging.level.root	info	Root logging level.
spring.h2.console.enabled	false	Enables/disables H2 web console.
spring.h2.console.path	/h2	Path for H2 web console.
spring.datasource.url	jdbc:h2:file:./discordModBot;MODE=MySQL;DATABASE_TO_LOWER=TRUE	Default datasource URL (file-based H2).
spring.datasource.username	sa	Database username.
spring.datasource.password	(empty)	Database password.
spring.datasource.driver-class-name	org.h2.Driver	JDBC driver class.
spring.jpa.hibernate.ddl-auto	none	Hibernate schema management mode.

Example (environment variables)

export DISCORD_MOD_BOT_OWNER_ID=123456789012345678
export DISCORD_MOD_BOT_BOT_TOKEN=your-token-here
export SPRING_DATASOURCE_URL=jdbc:mariadb://127.0.0.1:3306/discordmodbot
export SPRING_DATASOURCE_USERNAME=spring
export SPRING_DATASOURCE_PASSWORD=test
export SPRING_DATASOURCE_DRIVER_CLASS_NAME=org.mariadb.jdbc.Driver

Running on Linux (systemd, jar)

Spring Boot 4 removed embedded launch scripts. The recommended replacement for autostart is a systemd service that runs the fat jar directly with java -jar.

Build the jar

./gradlew bootJar

The jar will be at build/libs/DiscordModBot.jar.

Install on a server

sudo useradd --system --no-create-home --shell /usr/sbin/nologin discordbot
sudo mkdir -p /opt/discordmodbot
sudo cp build/libs/DiscordModBot.jar /opt/discordmodbot/DiscordModBot.jar
sudo chown -R discordbot:discordbot /opt/discordmodbot

Create the systemd unit

Create /etc/systemd/system/discordmodbot.service with:

[Unit]
Description=DiscordModBot
After=network.target

[Service]
Type=simple
User=discordbot
Group=discordbot
WorkingDirectory=/opt/discordmodbot
ExecStart=/usr/bin/java -jar /opt/discordmodbot/DiscordModBot.jar
Restart=on-failure
RestartSec=5
SuccessExitStatus=143
Environment="JAVA_OPTS=-Xms256m -Xmx1g"
# If you want env vars in a file:
# EnvironmentFile=/etc/discordmodbot/discordmodbot.env

[Install]
WantedBy=multi-user.target

If you want JVM args, either add them directly to ExecStart or change it to: ExecStart=/usr/bin/java $JAVA_OPTS -jar /opt/discordmodbot/DiscordModBot.jar

Enable and start

sudo systemctl daemon-reload
sudo systemctl enable discordmodbot
sudo systemctl start discordmodbot
sudo systemctl status discordmodbot

Logs

journalctl -u discordmodbot -f

Running with Docker or Podman (Boot Build Image)

Spring Boot can build an OCI image using buildpacks via the bootBuildImage task.

Build the image

./gradlew bootBuildImage

By default the image name is derived from the Gradle project name and version: docker.io/library/${project.name}:${project.version}.

If you want a custom image name:

./gradlew bootBuildImage --imageName=discordmodbot:latest

Run with Docker

docker run --rm -it --name discordmodbot \
  -e JAVA_TOOL_OPTIONS="-Xms256m -Xmx1g" \
  discordmodbot:latest

Run with Podman

podman run --rm -it --name discordmodbot \
  -e JAVA_TOOL_OPTIONS="-Xms256m -Xmx1g" \
  discordmodbot:latest

Persisting configuration and data

If you need to provide config files or persist data, mount a volume and reference it in your app configuration:

docker run --rm -it --name discordmodbot \
  -v /opt/discordmodbot:/opt/discordmodbot \
  -e SPRING_CONFIG_ADDITIONAL_LOCATION=/opt/discordmodbot/ \
  discordmodbot:latest

Note on Podman rootless

Podman rootless runs with a different UID mapping. If you write to a mounted host directory, ensure it is writable by the container user or use --userns=keep-id when appropriate.

Run container as a systemd service

You can run the container under systemd using either Docker or Podman. Adjust paths, env vars, and ports as needed.

Docker systemd unit

Create /etc/systemd/system/discordmodbot-docker.service:

[Unit]
Description=DiscordModBot (Docker)
After=network-online.target docker.service
Wants=network-online.target
Requires=docker.service

[Service]
Type=simple
Restart=on-failure
RestartSec=5
ExecStartPre=-/usr/bin/docker rm -f discordmodbot
ExecStart=/usr/bin/docker run --name discordmodbot \
  -e JAVA_TOOL_OPTIONS="-Xms256m -Xmx1g" \
  discordmodbot:latest
ExecStop=/usr/bin/docker stop discordmodbot

[Install]
WantedBy=multi-user.target

Enable and start:

sudo systemctl daemon-reload
sudo systemctl enable discordmodbot-docker
sudo systemctl start discordmodbot-docker

Podman systemd unit

Create /etc/systemd/system/discordmodbot-podman.service:

[Unit]
Description=DiscordModBot (Podman)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
Restart=on-failure
RestartSec=5
ExecStartPre=-/usr/bin/podman rm -f discordmodbot
ExecStart=/usr/bin/podman run --name discordmodbot \
  -e JAVA_TOOL_OPTIONS="-Xms256m -Xmx1g" \
  discordmodbot:latest
ExecStop=/usr/bin/podman stop discordmodbot

[Install]
WantedBy=multi-user.target

Enable and start:

sudo systemctl daemon-reload
sudo systemctl enable discordmodbot-podman
sudo systemctl start discordmodbot-podman