Signal LaTeX bot

A Signal bot that replies to incoming messages with LaTeX PNGs via JLaTeXMath.

Try it out by messaging +14046091473 on Signal (https://signal.me/#p/+14046091473).

The bot can also be added to group chats (you'll have to add the bot to contacts first), where it will generate LaTeX PNGs only for messages started with !latex, !tex, /latex, or /tex.

Installation

These are installations for a Debian-based installation.

Add an .env file containing the following:

DEPLOY_REMOTE=root@<IP or hostname of server to host the bot>

As root on a server, run the following:

# Run these three lines if you haven't installed signald already.
echo "deb https://updates.signald.org unstable main" > /etc/apt/sources.list.d/signald.list
curl https://updates.signald.org/apt-signing-key.asc | apt-key add -
apt update && apt install -y signald

useradd -m -s /bin/bash -g signald -b /var/lib signallatexbot
mkdir -p /opt/signallatexbot/deploy /opt/signallatexbot/images
chown signallatexbot /opt/signallatexbot/images

Ensure you have an account registered with signald already. Then, we will need to generate the bot configuration. On your local machine, build the bot with ./gradlew installDist. After that, run build/install/signal-latex-bot/bin/signal-latex-bot update-config --local and follow the prompts. Use /opt/signallatexbot/images for the output photo directory.

Then, upload the resulting config.json file to /var/lib/signallatexbot and ensure that it is owned by the signallatexbot user.

Copy signallatexbot.service to /etc/systemd/system/signallatexbot.service

Then on your local machine, run

./deploy-bot.sh

Finally, to ensure the bot starts on boot, run on the server, as root:

systemctl enable signallatexbot

You can run the following on the server as root to configure the bot's profile:

# Be the bot
su - signallatexbot
/opt/signallatexbot/deploy/bin/signal-latex-bot update-profile