Error using mod_wsgi, Django and MongoEngine

Question

I have set up a Django site with MongoEngine and I am trying to run it using Apache and mod_wsgi with a virtualenv.

It runs fine in development, but under Apache (on ubuntu 14.04.2) I get the following errors in the apache log:

mod_wsgi (pid=16130): Exception occurred processing WSGI script '/data/.../.../wsgi.py'.
Traceback (most recent call last):
  File "/data/.../.../wsgi.py", line 22, in application
    return get_wsgi_application()(environ, start_response)
  File "/data/venv/lib/python3.4/site-packages/django/core/wsgi.py", line 14, in get_wsgi_application
    django.setup()
  File "/data/venv/lib/python3.4/site-packages/django/__init__.py", line 17, in setup
    configure_logging(settings.LOGGING_CONFIG, settings.LOGGING)
  File "/data/venv/lib/python3.4/site-packages/django/conf/__init__.py", line 48, in __getattr__
    self._setup(name)
  File "/data/venv/lib/python3.4/site-packages/django/conf/__init__.py", line 44, in _setup
    self._wrapped = Settings(settings_module)
  File "/data/venv/lib/python3.4/site-packages/django/conf/__init__.py", line 92, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/data/.../.../settings.py", line 15, in <module>
    import mongoengine
  File "/data/venv/lib/python3.4/site-packages/mongoengine/__init__.py", line 1, in <module>
    from . import document
  File "/data/venv/lib/python3.4/site-packages/mongoengine/document.py", line 51
    class EmbeddedDocument(BaseDocument, metaclass=DocumentMetaclass):
                                                  ^
SyntaxError: invalid syntax

Any ideas why this might occur? This is particularly strange to me as I can't find the offending line in the mongoengine source.

My packages are:

dj-database-url==0.3.0
dj-static==0.0.6
Django==1.8
django-toolbelt==0.0.1
gunicorn==19.3.0
mongoengine==0.9.0
psycopg2==2.6
pymongo==2.8
static3==0.5.1

I'm not sure if it's related, but why is it using importlib from python2.7 and not python3.4?

My copy of mongoengine/document.py (installed using pip install) does not match the version in git, and has the following:

class EmbeddedDocument(BaseDocument, metaclass=DocumentMetaclass):
    ...
    # The __metaclass__ attribute is removed by 2to3 when running with Python3
    # my_metaclass is defined so that metaclass can be queried in Python 2 & 3

I'm new to python so I don't understand this, but it seems like a python 3 incompatibility?

mod_wsgi is somehow using Python 2 instead of Python 3; that syntax is not valid in Python 2. Can you show your Apache configuration and WSGI file? — Daniel Roseman, Apr 07 '15 at 11:34
Yes, you are right. I was using the ubuntu `libapache2-mod-wsgi` package with a virtualenv set up for python 3.4. Changing to `libapache2-mod-wsgi-py3` fixed it. Thank you for pointing me in the right direction. — zelanix, Apr 07 '15 at 11:39

score 0 · Accepted Answer · answered Apr 07 '15 at 14:02

The problem was that I was using the ubuntu libapache2-mod-wsgi package version of mod_wsgi which is built for Python 2.7 but my virtualenv was built around python 3.4.

The issue was resolved by uninstalling libapache2-mod-wsgi and installing libapache2-mod-wsgi-py3 which is built for Python 3.4.

Error using mod_wsgi, Django and MongoEngine

1 Answers1

Linked