service_hue_collector/README.md

# Hue RRD Flask dashboard

A lightweight Flask application for Raspberry Pi that reads the Philips Hue v2 API,
stores history in fixed-size RRDtool databases, and serves a local web dashboard.

The dashboard contains:

- One graph for every room and zone. Unavailable, off, and on lights form a stacked
  percentage area, with average intensity of shining lights drawn as a line.
- Temperature and illuminance graphs for every Hue sensor.
- 6-hour, 24-hour, 7-day, and 30-day time ranges.

RRD storage remains bounded automatically: raw samples are retained for 7 days,
approximately five-minute averages for 90 days, and hourly averages for two years.

## Install on Raspberry Pi OS or Debian

Install Python's virtual-environment support and the native headers needed to build
the RRDtool package, then install every Python dependency into `.venv`:

```bash
sudo apt update
sudo apt install python3 python3-venv python3-dev build-essential librrd-dev fonts-dejavu-core
python3 -m venv .venv
. .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -r requirements.txt
```

Create the Hue application key if you do not have one yet. Press the bridge link
button immediately before running:

```bash
curl -k -X POST https://BRIDGE_IP/api \
  -H 'Content-Type: application/json' \
  -d '{"devicetype":"local-hue-collector"}'
```

The returned `username` is the application key.

Configure and run the Flask application from the project directory:

```bash
cp .env.example .env
# Edit .env with the bridge IP and application key.
set -a
. ./.env
set +a
python -m hue_collector
```

Open `http://PI_ADDRESS:8000`. The RRD files are written to `DATA_DIR`, which defaults
to the project's `data/` directory.

## Run continuously with systemd

The included unit expects this repository at `/srv/service_hue_collector`, including
its `.venv` and `.env` files:

```bash
sudo chmod 600 /srv/service_hue_collector/.env
sudo cp hue-collector.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now hue-collector
```

The included unit uses a restricted dynamic service account and stores RRD files in
`/var/lib/hue-collector`. Inspect it with:

```bash
systemctl status hue-collector
journalctl -u hue-collector -f
```

After updating the application files, restart it with:

```bash
sudo systemctl restart hue-collector
```

## Configuration

- `HUE_BRIDGE_HOST`: Hue bridge IP or hostname; required.
- `HUE_APPLICATION_KEY`: Hue v2 application key; required.
- `HUE_VERIFY_TLS`: verify the bridge certificate; defaults to `false` because Hue
  bridges normally use a self-signed certificate.
- `COLLECT_INTERVAL_SECONDS`: sampling interval; defaults to 30 seconds. Changing it
  after RRD files have been created does not change those existing files' step.
- `LISTEN_HOST`: Flask bind address; defaults to `0.0.0.0` for LAN access.
- `LISTEN_PORT`: dashboard port; defaults to `8000`.
- `DATA_DIR`: RRD directory; defaults to `data`.

The application is intended for a trusted home network and does not provide
authentication or TLS. Restrict access with the Pi firewall if the network is not
trusted.

## Development

Create the virtual environment and install all application dependencies from the
requirements file:

```bash
sudo apt install python3-venv python3-dev build-essential librrd-dev fonts-dejavu-core
python3 -m venv .venv
. .venv/bin/activate
python -m pip install -r requirements.txt
python -m unittest discover -s tests
```