A Matrix bot written in Rust. It shows the weekly lunch menu for Mensa Furtwangen (HFU) and monitors websites for changes, sending a notification whenever a tracked value updates.

• Mensa menu — fetches the current week's menu from swfr.de; show today, a specific day, or the full week
• Website alerts — monitor any element on any page; get notified when its text, HTML, or any attribute changes
• Access control — admin users (set via env) plus a mutable allow-list
• Works in DMs and group rooms — no prefix needed in DMs; prefix with the bot name in group rooms
• Auto-join — accepts room invites automatically
• Persistent session — login is saved to disk; no new device created on redeploy
• E2EE — end-to-end encryption via matrix-sdk

Copy .env.example to .env and fill in your values:

MATRIX_HOMESERVER=https://matrix.example.com
MATRIX_USERNAME=@bot:example.com
MATRIX_PASSWORD=your-password

# Optional — defaults to the local part of MATRIX_USERNAME
BOT_NAME=bot

# Comma-separated list of Matrix IDs that always have full access
ADMIN_USERS=@you:example.com,@other:example.com

# Template for change notifications — all placeholders are optional
ALERT_TEMPLATE=Alert {name} changed\n\nOld: {old}\nNew: {new}

# Log level
RUST_LOG=info,matrix_sdk_crypto=error

Template placeholders: {name}, {url}, {old}, {new}, {css}, {property}

• Docker + Docker Compose
• Git

1. Clone the repository:

   git clone https://github.com/DMeurer/Matrix-Bot.git /opt/matrix-bot
   cd /opt/matrix-bot

2. Create and fill in your .env:

   cp .env.example .env
   $EDITOR .env

3. Start the bot:

   docker compose up -d

The bot logs in, saves its session to ./session/, and starts listening. The session/ directory is bind-mounted so it survives container rebuilds.

A cron job polls for new commits every minute and rebuilds automatically with zero downtime.

1. Make sure the current user can run docker without sudo:

   sudo usermod -aG docker $USER
   newgrp docker          # activates the group without logging out

2. Add to crontab (crontab -e):

   * * * * * sh /opt/matrix-bot/deployment/cronjob.sh
   

When a new commit lands on main, the job pulls the changes and runs docker compose up -d --no-deps --build. Concurrent runs are prevented by a lockfile. Logs are written to deployment/logs/cronjob.log.

git pull
docker compose up -d --build

cp .env.example .env   # fill in credentials
cargo run

cargo test