[Flix6x]

Description

Since v1.1.0, every container of the Docker image logs WARNING: python-dotenv could not parse statement starting at line 1 on startup.

• get_flexmeasures_env() looked up FLEXMEASURES_ENV in flexmeasures.cfg with dotenv_values(). That file is Python, so python-dotenv warns about any line that is not a plain KEY = value assignment, such as from datetime import timedelta on line 1. Spaces around = are fine for dotenv; imports and other statements are not.
• The bug is old (Drop need for .env #1759), but it only showed up now: between Speed up container startup and app boot (Docker, gunicorn, altair) #2512 and Docker image: read the mounted config again, restore gunicorn's logs, and let pip install into the venv #2811 the image did not find the config mounted at /app/instance, so there was nothing to parse. Docker image: read the mounted config again, restore gunicorn's logs, and let pip install into the venv #2811 (in v1.1.0) fixed that.
• Now the cfg is parsed with ast, without running it. Only a top-level string literal assigned to FLEXMEASURES_ENV counts, and the last one wins, as it does when the file runs. An expression is no longer mistaken for a string; a missing or unparsable file sets nothing here, and loading the config reports what is wrong with it, as before.
• The cfg is now only read when no FLEXMEASURES_ENV environment variable is set and the app is not in testing mode.
• The generate-openapi-specs hook stamped the spec with the dev version (1.1.1).
• Added changelog item in documentation/changelog.rst

How to test

pytest flexmeasures/utils/tests/test_config_utils.py

• test_flexmeasures_env_from_a_python_cfg_raises_no_dotenv_warning fails on main with the very warning from the logs (dotenv.main, "python-dotenv could not parse statement starting at line %s"), and passes here.
• test_read_flexmeasures_env_from_cfg covers plain and annotated assignments, last-one-wins, expressions, an absent setting and a file that is not Python.

Further Improvements

python-dotenv stays a dependency: the flask CLI uses it to read .flaskenv.
This could go into a v1.1.1 patch release.

Related Items

Regression surfaced by #2811.

🤖 Generated with Claude Code

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Documentation build overview

📚 flexmeasures | 🛠️ Build #35752641 | 📁 Comparing fa6b1cb against latest (055d54d)

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4 files changed

± changelog.html
± genindex.html
± _autosummary/flexmeasures.utils.config_utils.html
± api/v3_0.html