# Drop In URL previews server

A simple python server that handles /_matrix/media/*/preview_url requests, for servers like Dendrite.

## Installation
Just use docker.

Or you can run it yourself, but that's your choice.
```bash
pip install -r requirements.txt
PREVIEW_HOMESERVER=https://example.com python3 server.py
```

### Example docker-compose.yml
```yaml
version: "3"
services:
  url_previews:
    environment:
      - "PREVIEW_HOMESERVER=https://matrix.nexy7574.co.uk"
      - "FORWARDED_ALLOW_IPS=*"
    ports:
      - "2226:2226"
    restart: "unless-stopped"
    container_name: "dendrite-url-previews"
    volumes:
      - url_previews:/app/data/
    build: .  # there's no pre-built image

volumes:
  url_previews:
```

## Configuration

| Environment Variable  | Description                                                                                        | Example                         | Default                           |
|-----------------------|----------------------------------------------------------------------------------------------------|---------------------------------|-----------------------------------|
| `PREVIEW_HOMESERVER`  | The homeserver to use for the previews.                                                            | `https://matrix.nexy7574.co.uk` | The host name of the request URL. |
| `PREVIEW_HOST`        | The host IP/Name to listen to.                                                                     | `192.168.0.2`                   | `0.0.0.0`                         |
| `PREVIEW_PORT`        | The port to listen to.                                                                             | `8080`                          | `2226`                            |
| `PREVIEW_PROXY`       | A HTTP/HTTPS/SOCKS4/SOCKS5 proxy to use for all network requests.
| `FORWARDED_ALLOW_IPS` | The list of reverse proxy IPs to trust. See [Uvicorn docs](https://www.uvicorn.org/settings/#http) | *                               | `127.0.0.1`                       |