Files
ledgrab/server
alexei.dolgolyov 0e3ae78de7 fix(devices): address pre-merge review findings
Closes the issues surfaced by the pre-merge code review of the
expand-device-support branch.

CRITICAL #2 -- update_device double-encrypts secrets in memory.
storage/device_store.py round-tripped through device.to_dict() which
encrypts hue_username / hue_client_key / ble_govee_key / nanoleaf_token
via _enc(), but Device.__init__ does not decrypt. The cached
self._items[device_id] thus held ciphertext where plaintext belonged,
breaking runtime auth for paired devices on any update -- even an
innocuous rename. Sourcing kwargs from vars(device) directly avoids
the round-trip. Regression tests cover Nanoleaf and Hue.

HIGH #3 -- secrets leaked in GET /api/v1/devices response.
DeviceResponse previously returned nanoleaf_token / hue_username /
hue_client_key in plaintext (decrypted server-side from storage),
defeating the encryption-at-rest. Replaced with nanoleaf_paired and
hue_paired booleans. ble_govee_key intentionally stays -- it's a
user-managed value pasted from a third-party tool, must remain visible
for edit. Frontend types.ts + the one nanoleaf_token reader updated to
the boolean.

HIGH #4 -- SSRF surface. validate_lan_host() added to net_classify.py;
called from each new driver's validate_device (DDP / Yeelight / WiZ /
LIFX / Govee / OPC / Nanoleaf) and from pair_device. Rejects literal
public IPs with a descriptive ValueError; non-IP hostnames pass
through (mDNS labels, bare hostnames). RFC6890 ranges (documentation,
former class E) are accepted as LAN-like since Python's
ipaddress.is_private treats them so -- correct policy for LedGrab.

HIGH #5 -- decrypt failure deletes the device row. _dec() now catches
the exception, logs an error, and returns "" instead of propagating.
Without the fix, a regenerated data/.secret_key would silently make
every Hue / Nanoleaf / BLE-Govee device disappear from the device list
on next startup. Regression test asserts a corrupt envelope leaves the
device hydratable.

HIGH #6 -- update_device route does not rstrip("/") for non-WLED.
Moved the trim before the WLED-specific scheme inference so every
device type gets consistent URL normalization between create and
update.

MEDIUM #7 -- Govee discovery port 4002 collision. Added a lazily-
initialized module-level asyncio.Lock that serializes concurrent
discover_govee_devices() calls; the previous behavior had the second
parallel scan silently return [] when the first still held port 4002.
Error message also clarified to mention another Govee tool.

MEDIUM #8 -- Nanoleaf discover() leaked browser tasks on cancellation.
Moved the browser cancel loop into the finally block so an interrupted
mDNS scan still tears them down.

MEDIUM #9 -- pair endpoint logged user-supplied URL with exc_info=True.
Added _sanitize_url_for_log() that strips userinfo + fragment, and
demoted the log from exc_info to type(exc).__name__ + str(exc) so a
hostile receiver's response body can't end up in the log file.

LOW -- Nanoleaf was the only client without a .port property. Added
one (returns NANOLEAF_PORT, fixed) for cross-driver symmetry.

LOW -- no end-to-end pair-then-create coverage. Added
TestPairThenCreateFlow.test_pair_then_create_persists_encrypted_token
which exercises the full path: POST /api/v1/devices/pair returned
fields, store.create_device, then asserts (a) in-memory plaintext,
(b) to_config() plaintext, (c) persisted ciphertext, (d) API response
strip + paired-boolean.

Tests: 1379 pass (was 1358 -- 21 new regression tests added).
ruff clean. TypeScript clean.
2026-05-16 11:06:10 +03:00
..
2026-05-10 23:57:47 +03:00

LedGrab - Server

High-performance FastAPI server that captures screen content and controls WLED devices for ambient lighting.

Overview

The server component provides:

  • 🎯 Real-time Screen Capture - Multi-monitor support with configurable FPS
  • 🎨 Advanced Processing - Border pixel extraction with color correction
  • 🔧 Flexible Calibration - Map screen edges to any LED layout
  • 🌐 REST API - Complete control via 25+ REST endpoints
  • 💾 Persistent Storage - JSON-based device and configuration management
  • 📊 Metrics & Monitoring - Real-time FPS, status, and performance data

Quick Start

# Start server
docker-compose up -d

# View logs
docker-compose logs -f

# Stop server
docker-compose down

Server runs on: http://localhost:8080

Option 2: Python

# Create virtual environment
python -m venv venv

# Activate
source venv/bin/activate  # Linux/Mac
venv\Scripts\activate      # Windows

# Install dependencies
pip install .

# Set PYTHONPATH
export PYTHONPATH=$(pwd)/src  # Linux/Mac
set PYTHONPATH=%CD%\src       # Windows

# Run server
uvicorn ledgrab.main:app --host 0.0.0.0 --port 8080

Installation

Requirements

  • Python 3.11+ (for Python installation)
  • Docker & Docker Compose (for Docker installation)
  • WLED device on your network

See ../INSTALLATION.md for comprehensive installation guide.

Configuration

Configuration File

Edit config/default_config.yaml:

server:
  host: "0.0.0.0"
  port: 8080
  log_level: "INFO"

processing:
  default_fps: 30        # Target frames per second
  max_fps: 60           # Maximum allowed FPS
  border_width: 10      # Pixels to sample from edge

wled:
  timeout: 5            # Connection timeout (seconds)
  retry_attempts: 3     # Number of retries

storage:
  devices_file: "data/devices.json"

logging:
  format: "json"
  file: "logs/ledgrab.log"

Environment Variables

# Server configuration
export LEDGRAB_SERVER__HOST="0.0.0.0"
export LEDGRAB_SERVER__PORT=8080
export LEDGRAB_SERVER__LOG_LEVEL="INFO"

# Processing configuration
export LEDGRAB_PROCESSING__DEFAULT_FPS=30
export LEDGRAB_PROCESSING__BORDER_WIDTH=10

# WLED configuration
export WLED_WLED__TIMEOUT=5

Usage

WLED Device Setup

Important: Configure your WLED device using the official WLED web interface before connecting it to this controller:

  1. Access WLED Interface: Open http://[wled-ip] in your browser
  2. Configure Device Settings:
    • Set LED count and type
    • Configure brightness, color order, and power limits
    • Set up segments if needed
    • Configure effects and presets

This controller only sends pixel color data - it does not manage WLED settings like brightness, effects, or segments. All WLED device configuration should be done through the official WLED interface.

API Documentation

Quick Example

# 1. Add device
curl -X POST http://localhost:8080/api/v1/devices \
  -H "Content-Type: application/json" \
  -d '{"name":"Living Room","url":"http://192.168.1.100","led_count":150}'

# 2. Start processing
curl -X POST http://localhost:8080/api/v1/devices/{device_id}/start

# 3. Check status
curl http://localhost:8080/api/v1/devices/{device_id}/state

Testing

# Run all tests
pytest

# Run with coverage
pytest --cov=ledgrab --cov-report=html

# Run specific test
pytest tests/test_screen_capture.py -v

Development

Project Structure

src/ledgrab/
├── main.py              # FastAPI application
├── config.py            # Configuration
├── api/                 # API routes
├── core/                # Core functionality
│   ├── screen_capture.py
│   ├── wled_client.py
│   ├── calibration.py
│   └── processor_manager.py
├── storage/             # Data persistence
└── utils/               # Utilities

Code Quality

# Format code
black src/ tests/

# Lint code
ruff check src/ tests/

License

MIT - see ../LICENSE

Support