Google App Engine aborts on missing environment variable DJANGO_SETTINGS_MODULE - django

Question

This is a follow-up question for Google App Engine and Django support:
The tutorial works great for an empty project, however when I try to deploy an existing Django app to Google App Engine, it starts throwing errors:
Traceback (most recent call last):
File "/python27_runtime/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 223, in Handle
result = handler(dict(self._environ), self._StartResponse)
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/core/handlers/wsgi.py", line 219, in __call__
self.load_middleware()
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/core/handlers/base.py", line 39, in load_middleware
for middleware_path in settings.MIDDLEWARE_CLASSES:
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/utils/functional.py", line 184, in inner
self._setup()
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/conf/__init__.py", line 40, in _setup
raise ImportError("Settings cannot be imported, because environment variable %s is undefined." % ENVIRONMENT_VARIABLE)
ImportError: Settings cannot be imported, because environment variable DJANGO_SETTINGS_MODULE is undefined.
And a second, which might be related:
Traceback (most recent call last):
File "/python27_runtime/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 223, in Handle
result = handler(dict(self._environ), self._StartResponse)
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/core/handlers/wsgi.py", line 219, in __call__
self.load_middleware()
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/core/handlers/base.py", line 39, in load_middleware
for middleware_path in settings.MIDDLEWARE_CLASSES:
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/utils/functional.py", line 184, in inner
self._setup()
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/conf/__init__.py", line 42, in _setup
self._wrapped = Settings(settings_module)
File "/python27_runtime/python27_lib/versions/third_party/django-1.4/django/conf/__init__.py", line 95, in __init__
raise ImportError("Could not import settings '%s' (Is it on sys.path?): %s" % (self.SETTINGS_MODULE, e))
ImportError: Could not import settings 'settings' (Is it on sys.path?): No module named settings
I have modified my settings.py as per the tutorial. The app deploys without problems and the syncdb works as well; the database and all required tables are in place.
I found this reference to the error message as shown in the log but its suggested fix did not help.
Any ideas what might be causing this?
EDIT:
To shorten this already lengthy question I removed the previously posted wsgi.py file. I had nothing to do with this issue.
EDIT 2:
I think I made a small improvement and GAE is now complaining:
ImportError: No module named properties
I presume there might be an entry missing in my app.yaml file but I have no clue as to which file that may be. I found some references regarding missing modules but none that reflect this error message...

Answer 1

After much trial and error I managed to solve this, albeit partially:
I did not manage to get my existing PyCharm project deployed (yet). As I was keen to have a version running on GAE I went for a different approach and created a new empty Django project (project 2) on my local machine.
I first deployed the blank project using this tutorial which ran fine. I then copied my models.py file from my existing PyCharm project to project 2 and added an app called properties which uses the models.py file. Initially this went wrong as GAE kept complaining it could not find my properties app. After fiddling about with it, it suddenly appeared in my admin. I'm not sure what caused the initial problem but it's working now.
Things crucial to success for me:
I added the following to the very top of my settings.py:
import os
ROOT_PATH = os.path.dirname(__file__)
... and then replaced the default STATIC_ROOT with:
STATIC_ROOT = ROOT_PATH + os.sep + 'static'
Then I ran:
python manage.py collectstatic
from the dir of project 2. This collects the required static files which Django admin uses (image files, css files etc)
So, I currently have a stripped down version of my original project running on GAE. Things that are missing:
The original project used grappelli for a more styled admin interface. I'm not sure whether this will run on GAE. EDIT: Deploying Grappelli on GAE is reasonbly easy. Just copy the Grappelli package to your project dir and run manage.py collectstatic. Also add grappelli urls as per documention. Redeploy. Done.
The original project uses a module called templated_email to send out templated emails from my properties app. Same as grappelli: I'm not sure whether this is supported by GAE. Hopefully it will run on GAE as it is crucial for my specific app. EDIT: I bumped into this little gem which makes templated_email obsolete and lets me plug into GAE mail system.
To be honest, this approach partially defies the benefits of PyCharm which should fully support Django and GAE out of the box. It will probably require some additional research and tweaking to get that up and running.
Any comments or insights re the above are obviously appreciated!