dab-rs

Discord Announcement Bot, implemented in Rust

A bot that lets users set a chime that is played every time they connect to a channel. Reminiscing that good old "User joined your channel" from Teamspeak-times; But this time, customizable!

Features

Slash-commands

After setting the name of the base command, the following commands will be available:

/base set url       # sets chime of user to given url (that links to an audio-file)
/base set file      # sets chime of user to given attachment
/base clear         # clears chime of user, if present
/base admin forbid  # sets role whose user's chimes are not played

Behaviour

If some user connects to a channel, the bot will join that channel and play the chime of the user, if configured. The bot will leave after a configured timespan, if no other user joins.

When multiple users connect at the same time, their chimes will be queued and played in FCFS-order, also considering different channels in the same guild.

Localization

This bot is implemented to have full support for localization. This is achieved by using .ftl resources with fluent-rs.

How to get started

Packages

Available on the AUR.

Compilation

Ensure that ffmpeg and opus are installed. The package names to install them on your distro my differ. For arch-based distros, the following commands will get you started:

$ sudo pacman -S opus ffmpeg cargo && git clone https://github.com/Sir-Photch/dab-rs.git && cd dab-rs && cargo build --release

Cross-compile Raspberry Pi

If you want to run the bot on a raspberry, you I suggest using the Cross toolchain to cross-compile. You can set it up as follows:

Docker

If you haven't already set up docker, you can do it as follows:

$ sudo pacman -S docker && sudo groupadd docker && sudo usermod -aG docker $USER

You may need to reboot for changes to apply. After that, verify a working docker installation with docker run hello-world.

Cross

Assuming you have the rust toolchain installed.

$ cargo install cross

Compilation

Ensure that docker.service is running:

$ systemctl start docker

Then, depending on your raspberry installation, run

$ cross build --release --target <target>

For a RPI4 with a 64-bit kernel, use aarch64-unknown-linux-gnu. Note that for cross-compilation, dab-rs statically links to openssl; Updates to your systems libssl are not incorporated unless recompiled.

Further reading

• Docker post-installation
• Cross on github

Database

This bot needs a database connection to run. Create a database that is to be used and specify the connection details in Settings.toml. You do not need to create any tables, this will be ensured at runtime.

You need to setup a postgres-database though:

create database dab_rs;
create user INSERT_USERNAME_HERE with password 'INSERT_PASSWORD_HERE';
grant all privileges on database dab_rs to INSERT_USERNAME_HERE;
alter database dab_rs owner to INSERT_USERNAME_HERE;

Configuration

There needs to be a Settings.toml inside the directory of the executable. Consider the following template:

USERDATA_DIR = "/path/to/userdata/dir"
API_TOKEN = "foo bar baz"
BUS_SIZE = 200
COMMAND_ROOT = "dab"
CHIME_DURATION_MAX_MS = 3000
FILE_SIZE_LIMIT_KILOBYTES = 5000
CONNECTION_TIMEOUT_MILLISECONDS = 10000
RESOURCE_DIR = "/path/to/resource/dir"
DEFAULT_LOCALE = "en-US"
DB_HOSTNAME = "localhost"
DB_USERNAME = "your username"
DB_PASSWORD = "your password"
DB_NAME = "dab_rs"
LOG_PATH = "/path/to/log.file"

• USERDATA_DIR specifies the path where the chimes will be saved.
• API_TOKEN is your unique token from discord.
• BUS_SIZE is the queuesize for joins, globally.
• COMMAND_ROOT is the name of the base command. This may be reconfigured, depending on other bots in your guild(s).
• CHIME_DURATION_MAX_MS is the maximum duration of a users chime, in milliseconds.
• FILE_SIZE_LIMIT_KILOBYTES is the maximum size of a users chime on disk, in KB.
• CONNECTION_TIMEOUT_MILLISECONDS is the duration that the bot will remain connected to a channel, after no other user joins a channel in the guild, in milliseconds.
• RESOURCE_DIR is the path to the directory containing the folder structure for localization.
• DEFAULT_LOCALE is the fallback locale that is to be used when translations for a users locale are not available.
• DB_* are the credentials and connection details to the postgresql-database that dab-rs will use.
• LOG_PATH is the file where logs will be saved to.

Commandline options

• -c, --config: specifies path to configuration file
• -v, --verbose: enables verbose logging in stdout
• -b, --beats: explicitly enables verbose heartbeat logging

Localization

By default, this repository contains translations in resources. To be able to use them, reference this folder in the configuration for your setup. Localizations are dynamically loaded at startup, as long as the folder names obey the Unicode Language Identifier standards, e.g. en-US or de.

Systemd service

Consider this unit as an example for a systemd-service. Depending on your distro, you may place it in /etc/systemd/system:

dab-rs.service:
--------------------------------------
[Unit]
Description=dab-rs Discord Bot
Wants=network-online.target
Requires=postgresql.service
After=network-online.target postgresql.service
[Service]
WorkingDirectory=/path/to/working/directory
ExecStart=/path/to/working/directory/dab-rs
[Install]
WantedBy=multi-user.target

Note that you may need to modify WorkingDirectory and ExecStart based on your setup.

Known issues

Won't work on systems with only one CPU-core.