lunchbot

Bot that scrapes the daily lunch menus from the DESY canteen (Alsterfood) and Cafe CFEL, generates AI preview images for each dish, and posts everything as a formatted table to a Mattermost channel.

Example:

Each execution scrapes the menu, generates images (skipping dishes that already have a cached image in the cloud), uploads them, and posts a single message. To run the bot periodically, use e.g. cron.

Usage

Requirements

Install uv:

curl -LsSf https://astral.sh/uv/install.sh | sh

Configuration

Create a .env file in the project root. All variables are listed below:

Image generation

Variable	Required	Description
API_TO_USE	yes	Which image generation backend to use: "openai" or "huggingface"
OPENAI_API_KEY	if using OpenAI	Your OpenAI API key
HUGGINGFACE_API_URL	if using HF	HF Inference API endpoint, e.g. https://router.huggingface.co/hf-inference/models/black-forest-labs/FLUX.1-schnell
HUGGINGFACE_API_TOKEN	if using HF	Your Hugging Face API token
IMAGE_PROMPT_PREFIX	no	Style prefix prepended to every image prompt for consistent visuals (e.g. "Professional food photography, overhead shot: ")
USE_OPENAI_IMAGE_URL	no	If "true", use the temporary OpenAI image URL directly instead of uploading to the cloud (expires after 1 hour)

Menu sources

Variable	Required	Description
ALSTERFOOD_WEBSITE_URL	yes	URL of the DESY Alsterfood canteen menu page
CFEL_WEBSITE_URL	no	URL of the Cafe CFEL menu page (iMensa)

Image cloud storage

Images are uploaded to a WebDAV-compatible cloud so they remain available indefinitely. Not needed if USE_OPENAI_IMAGE_URL="true".

Variable	Required	Description
IMAGE_CLOUD_UPLOAD_URL	yes*	WebDAV upload base URL
IMAGE_CLOUD_UPLOAD_TOKEN	yes*	Credentials for the upload (user:password)
IMAGE_CLOUD_DOWNLOAD_URL	yes*	Public download base URL for the uploaded images

Mattermost

Variable	Required	Description
MATTERMOST_WEBHOOK_URL	yes	Incoming webhook URL for posting the daily menu
MATTERMOST_WEBHOOK_URL_ALERT	no	Separate webhook URL for error alerts
MATTERMOST_USERNAME	no	Display name for the bot (default: "Lunchbot")
ALERT_PREFIX	no	Text prepended to error alert messages (e.g. "ALERT @someone ")

Message content

Variable	Required	Description
MESSAGE_PREFIX	no	Text prepended to the daily message
MESSAGE_SUFFIX_MON ... MESSAGE_SUFFIX_SUN	no	Day-specific suffix appended to the message

For different messages in even/odd weeks, use MESSAGE_SUFFIX_MON_EVEN, MESSAGE_SUFFIX_MON_ODD, etc. These take precedence over the base day suffix when set.

Other

Variable	Required	Description
HOSTNAME	no	Identifier logged at startup (default: "unknown_host")

Run the bot

uv run scripts/run_lunchbot.py

This runs the bot once. Use cron or a similar scheduler to run it daily.

Run with Docker

docker build -t lunchbot .
docker run -it --env-file .env lunchbot uv run scripts/run_lunchbot.py

Development

uv sync --dev
uv run pre-commit install