A small Flask service that polls Netatmo's Weather API every ten minutes, stores the readings in RRDtool databases, and serves a responsive graph dashboard.

What it stores

The service creates outdoor.rrd, wind.rrd, bedroom.rrd, study.rrd, and living.rrd. Each has ten-minute archives for the last two weeks and six-hour archives covering a year. Day, two-week, and year PNG graphs are rendered on demand. The wind graph splits average wind into 12 colored direction bands and draws gusts as a line.

The Outdoor module does not contain a pressure sensor, so outdoor.rrd combines its temperature/humidity with pressure from the main station. A module without dashboard_data is skipped until it becomes reachable again.

Prerequisites and setup

Install the RRDtool Python binding and native library using your operating system package manager (for example apt install python3-rrdtool on Debian or Ubuntu), then set up the Python application. If your distribution does not provide the binding, pip install -r requirements.txt installs its PyPI package but may require the RRDtool development headers and a C compiler.

python3 -m venv .venv
.venv/bin/pip install -r requirements.txt
cp .env.example .env

Add the client ID and secret for the Netatmo application GetNetatmoData v2 to .env. Ensure NETATMO_REDIRECT_URI exactly matches a redirect URI configured for that application, then perform the initial read_station authorization:

set -a
. ./.env
set +a
.venv/bin/python scripts/get_netatmo_token.py

The helper opens Netatmo's consent page. After approval, paste the complete URL from the browser's address bar back into the prompt. This works even if the local callback page itself cannot be reached. The script exchanges the authorization code and writes the token file with mode 0600.

The service loads NETATMO_TOKEN_FILE at startup. Before an access token expires, it refreshes it and atomically saves both the new access token and any rotated refresh token. Values in the token file take precedence over initial token values in .env. Client credentials remain environment-only and are never written to the token file or an RRD.

Export the file and run Flask:

set -a
. ./.env
set +a
.venv/bin/flask --app wsgi run --host 0.0.0.0

Open http://localhost:5000/. Keep one application worker because the polling scheduler runs inside the service process. Alternatively set START_COLLECTOR=false in web workers and invoke this from a system timer:

.venv/bin/flask --app wsgi collect-now

RRD_FOLDER configures the database directory (default ./rrd). The module variables in .env.example allow the five Netatmo display names to be changed. Set URL_PREFIX=/w to mount the dashboard, static assets, and every API endpoint below /w; leave it empty to serve from the site root. When a prefix is set, open http://localhost:5000/w/ instead.

HTTP API

GET /last/<rrd-name>/<data-point>
GET /graph/<rrd-name>/<period>
GET /graph/<rrd-name><period>       # compact compatibility form
GET /health

Periods are day, 2weeks, and year. Examples:

curl http://localhost:5000/last/outdoor/humidity
curl --output wind.png http://localhost:5000/graph/wind/2weeks

Data points are:

outdoor: min_temp, max_temp, humidity, pressure
wind: gust, average, angle
bedroom, study, living: temperature, co2, humidity

The service creates missing RRDs at startup but deliberately does not alter an existing RRD schema. If a schema is changed in code, migrate or archive the old files before restarting.