Passing Environment Variables from .env.dev to tox

You can pass environment variables from your .env.dev file to tox using the passenv or setenv directives in your tox.ini file, combined with a Python package that loads environment variables.

Here are a few approaches:

Option 1: Using python-dotenv in tox

1. First, add python-dotenv to your dependencies:

INICopied
[testenv]
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
    python-dotenv

2. Then modify your commands to load the environment variables before running tests:

INICopied
commands =
    python -c "import os, dotenv; dotenv.load_dotenv(os.path.join(os.path.dirname(os.path.dirname(os.getcwd())), '.env.dev'))"
    python manage.py test

Option 2: Using tox's built-in env file support (tox 4.0+)

If you're using tox 4.0 or newer, you can use the built-in env file support:

INICopied
[testenv]
env_file = ../.env.dev
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
commands =
    python manage.py test

Option 3: Using passenv with Docker

Since you mentioned you're using Docker, you could also pass environment variables from the host to tox via Docker:

1. In your tox.ini, use passenv to allow environment variables to pass through:

INICopied
[testenv]
passenv = *
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
commands =
    python manage.py test

2. Then in your Docker command or docker-compose file, load the environment variables:

BASHCopied
docker run --env-file .env.dev -v $(pwd):/app -w /app/app python:3.10 tox

Choose the approach that best fits your workflow. Option 2 is the most straightforward if you're using a newer version of tox.

Passing Environment Variables from .env.dev to tox

You can pass environment variables from your .env.dev file to tox using the passenv or setenv directives in your tox.ini file, combined with a Python package that loads environment variables.

Here are a few approaches:

Option 1: Using python-dotenv in tox

INICopied
[tox]
envlist =
    py310-django50
    py310-django51
    py312-django50
    py312-django51
skipsdist = True
skip_missing_interpreters = True

[testenv]
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
    python-dotenv
setenv =
    DJANGO_SETTINGS_MODULE = django_project.settings
    DEBUG = False
commands =
    python -c "import dotenv; dotenv.load_dotenv('../.env.dev')"
    python manage.py test

Option 2: Using tox's built-in env file support (tox 4.0+)

If you're using tox 4.0 or newer, you can use the built-in env file support:

INICopied
[tox]
envlist =
    py310-django50
    py310-django51
    py312-django50
    py312-django51
skipsdist = True
skip_missing_interpreters = True
env_file = ../.env.dev

[testenv]
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
setenv =
    DJANGO_SETTINGS_MODULE = django_project.settings
    DEBUG = False
commands =
    python manage.py test

Option 3: Using a custom script to load environment variables

Create a small Python script (e.g., load_env.py) in your app directory:

PYTHONCopied
import os
import sys

def load_env(env_file):
    with open(env_file) as f:
        for line in f:
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            key, value = line.split('=', 1)
            os.environ[key] = value

if __name__ == "__main__":
    load_env('../.env.dev')
    os.execvp(sys.argv[1], sys.argv[1:])

Then update your tox.ini:

INICopied
[testenv]
deps =
    django50: Django==5.0.*
    django51: Django==5.1.*
    sentry_sdk
setenv =
    DJANGO_SETTINGS_MODULE = django_project.settings
    DEBUG = False
commands =
    python load_env.py python manage.py test

Choose the option that best fits your workflow. Option 1 or 2 are generally recommended as they use established methods for handling environment variables.