Using additional command line arguments with gunicorn

Question

Assuming I'm starting a Flask app under gunicorn as per http://gunicorn.org/deploy.html#runit, is there a way for me to include/parse/access additional command line arguments?

E.g., can I include and parse the foo option in my Flask application somehow?

gunicorn mypackage:app --foo=bar

Thanks,

Answer 1

You can't pass command line arguments directly but you can choose application configurations easily enough.

$ gunicorn 'mypackage:build_app(foo="bar")'

Will call the function "build_app" passing the foo="bar" kwarg as expected. This function should then return the WSGI callable that'll be used.

Answer 2

I usually put it in __init.py__ after main() and then I can run with or without gunicorn (assuming your main() supports other functions too).

# __init__.py

# Normal entry point
def main():
  ...

# Gunicorn entry point generator
def app(*args, **kwargs):
    # Gunicorn CLI args are useless.
    # https://stackoverflow.com/questions/8495367/
    #
    # Start the application in modified environment.
    # https://stackoverflow.com/questions/18668947/
    #
    import sys
    sys.argv = ['--gunicorn']
    for k in kwargs:
        sys.argv.append("--" + k)
        sys.argv.append(kwargs[k])
    return main()

That way you can run simply with e.g.

gunicorn 'app(foo=bar)' ...

and your main() can use standard code that expects the arguments in sys.argv.