# MiniDiscovery

MiniDiscovery is a minimal, self-contained service discovery tool inspired by Consul, built with Python (FastAPI, Twisted, SQLite).

It provides basic service registration, health checking, and discovery via both an HTTP API and a DNS interface.

## Core Features

*   **Service Registration/Deregistration:** Register services with address, port, tags, and metadata via an HTTP API.
*   **Health Checking:** Automatically performs simple TCP health checks on registered services.
*   **HTTP API Discovery:** Query for services (including filtering by tags and health status).
*   **DNS Discovery:** Query for healthy services using DNS A, SRV, and TXT records (e.g., `_web._tcp.laiska.local`, `api.laiska.local`).
*   **Authentication:** API endpoints are protected using HMAC-signed API tokens.
*   **Persistence:** Uses a simple SQLite database (`.db` file) for storing service and token information.

## Components

The script runs three main components as separate processes:

1.  **FastAPI Server:** Handles the HTTP API requests.
2.  **Twisted DNS Server:** Responds to DNS queries for registered services.
3.  **Health Checker:** Periodically checks the health of registered services.

## Quick Start

### 1. Prerequisites

*   Python 3.8+
*   Dependencies listed in `requirements.txt` (`pip install -r requirements.txt`)

### 2. Running Directly

```bash
# First run: Set the initial admin token environment variable
export MINIDISCOVERY_ADMIN_TOKEN="your_very_secret_admin_token_here"

# Run the script (uses default ports and file paths)
python MiniDiscovery.py
```

*   An HMAC key file (`minidiscovery.key`) will be generated if it doesn't exist.
*   A database file (`minidiscovery_data.db`) will be created.

### 3. Running with Docker (Recommended)

(Requires the provided `Dockerfile` and `requirements.txt`)

```bash
# Build the image
docker build -t minidiscovery:latest .

# Create a directory on host for persistent data (key and db)
mkdir ./md_data
# !!! If you have an existing minidiscovery.key, place it in ./md_data !!!

# Run the container
docker run -d --name minidiscovery \
  -p 8500:8500/tcp \
  -p 10053:10053/tcp \
  -p 10053:10053/udp \
  -v ./md_data:/data \
  -e MINIDISCOVERY_ADMIN_TOKEN="your_very_secret_admin_token_here" \
  minidiscovery:latest
```

*   The container expects the database and HMAC key in the `/data` volume.
*   The `MINIDISCOVERY_ADMIN_TOKEN` is required on the first run to create the initial admin token.

## Configuration

*   **Database Path:** `--db-path` argument or `MINIDISCOVERY_DB_PATH` environment variable. (Defaults to `minidiscovery_data.db`, or `/data/minidiscovery_data.db` in Docker).
*   **HMAC Key File:** `--hmac-key-file` argument. (Defaults to `minidiscovery.key`, or `/data/minidiscovery.key` in Docker).
*   **Ports:** `--api-port`, `--dns-port`.
*   **Initial Admin Token:** `MINIDISCOVERY_ADMIN_TOKEN` environment variable (needed for first run only).