Unusual warning with djcelery, billiard, and the django_settings_module

Question

When running manage.py celeryd for async processes, everything works as expected but i'm getting a weird warning at every start-up. It's not causing any errors, but i'm having trouble making it disappear or understanding its meaning.

Here it is:

/home/user/lib/python2.7/billiard-2.7.3.15-py2.7-linux 
-x86_64.egg/billiard/forking.py:455:           
UserWarning: Will add directory '/home/user/webapps/django/proj' to path! 
This is  necessary to accommodate pre-Django 1.4 layouts using setup_environ.
You can skip this warning by adding a DJANGO_SETTINGS_MODULE=settings 
environment variable.

W_OLD_DJANGO_LAYOUT % os.path.realpath(project_dir)

This is unusual because the django settings module has been added to my wsgi, and it works for everything but this. Does it want me to add the settings to httpd.conf or something?

Thanks

Answer 1

Oddly enough, I just ran into the same problem! Looking up the file in question (billiard/forking.py), I found this function:

def _Django_old_layout_hack__save():
    if 'DJANGO_PROJECT_DIR' not in os.environ:
        try:
            settings_name = os.environ['DJANGO_SETTINGS_MODULE']
        except KeyError:
            return  # not using Django.

        try:
            project_name, _ = settings_name.split('.', 1)
        except ValueError:
            return  # not modified by setup_environ

        project = __import__(project_name)
        try:
            project_dir = os.path.normpath(_module_parent_dir(project))
        except AttributeError:
            return  # dynamically generated module (no __file__)
        warnings.warn(UserWarning(
            W_OLD_DJANGO_LAYOUT % os.path.realpath(project_dir)
        ))
        os.environ['DJANGO_PROJECT_DIR'] = project_dir

This function apparently does some sanity checks on os.environ. Notice that, after retrieving DJANGO_SETTINGS_MODULE, it tries to split the module name by a period. This code seems to assume that, if your DJANGO_SETTINGS_MODULE is a top-level module (as it is, by default), then your environment hasn't been modified.

Unfortunately, if it isn't a top-level module, it seems to assume that you used setup_environ, and that it must now add the project directory to the path.

In my case, I had simply moved the simple settings.py module out into its own settings package, splitting it up into the common, and development/production files. Of course, I had to modify manage.py and wsgi.py to point to the correct settings module. Which, of course, started to trigger this warning.

The way I worked around it was by adding the DJANGO_PROJECT_DIR variable directly in my manage.py. I'm not sure if I'll need to add it elsewhere (e.g. in production environments), but that's all I've run into so far.

Here's the relevant line in manage.py:

if __name__ == "__main__":
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "settings.current")

    # Add the project directory to the path, to appease billiard
    os.environ.setdefault("DJANGO_PROJECT_DIR",
        os.path.dirname(os.path.realpath(__file__)))