Waitress on Heroku giving error - django

Question

I am trying to switch from Gunicorn to Waitress on Heroku. In the logs, I keep getting an error from Waitress:
Error: Bad module 'cardisle'
In my procfile, I have:
web: waitress-serve --port=$PORT cardisle.wsgi:application
If I remove the .wsgi extension, I get a different error:
Error: Bad object name 'application'
I have tried changint the object name to wsgifunc as well since it's in the Waitress doc, but no luck.
Any help would be appreciated. I have a wsgi.py file with the following:
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "cardisle.settings")
import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()

Answer 1

Here's an awful fact about waitress: it is hiding info from you.
If you look at the source, "Bad Module" is code for "There was a failure importing your application from the wsgi module."
To see the error, try:
logging into a dyno with heroku run bash
navigating to the directory with wsgi.py in it (with cd)
opening a shell with python
running import wsgi
When I hit this error and did this, I got:
~/proj/proj $ python
Python 2.7.9 (default, Dec 11 2014, 17:18:51)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import wsgi
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "wsgi.py", line 36, in <module>
application = get_wsgi_application()
File "/app/.heroku/python/lib/python2.7/site-packages/django/core/wsgi.py", line 14, in get_wsgi_application
django.setup()
File "/app/.heroku/python/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
apps.populate(settings.INSTALLED_APPS)
File "/app/.heroku/python/lib/python2.7/site-packages/django/apps/registry.py", line 85, in populate
app_config = AppConfig.create(entry)
File "/app/.heroku/python/lib/python2.7/site-packages/django/apps/config.py", line 86, in create
module = import_module(entry)
File "/app/.heroku/python/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
ImportError: No module named debug_toolbar
Which is a much more helpful error. In my case, I had set DJANGO_SETTINGS_MODULE to 'local' in production, (which did not have the appropriate requirements,) and so the import failed.
The exact nature of your problem will vary, but I'll mention a case that frustrated me when I started out:
If you are running web: waitress-serve --port=$PORT cardisle.wsgi:application, you may need to change your PYTHONPATH environment variable so that PYTHONPATH+cardisle.wsgi is a fully-formed extant path on the machine in question.
I'll open a PR for waitress this evening that tries to bubble up the import error. Best of luck otherwise!

Answer 2

The wsgi.py file should be in the cardisle directory. Waitress is trying to import cardisle.wsgi.

Answer 3

I think I found the answer. If your project is laid out like this (as they are by default):
cardisle/
cardisle/
wsgi.py
app1/
app2/
app3/
Try this Procfile instead:
web: waitress-serve --port=$PORT cardisle.cardisle.wsgi:application
I thought of this because Dave Hall's sample project has a different layout:
projectname/
wsgi.py
apps/
app1/
app2/
app3/
Which has the wsgi.py file at a higher level. You probably followed his tutorial, but as far as I can tell the default Django layout doesn't quite work like that.

Answer 4

Try modifying your WSGI file like this(For Django 1.7):
from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()
I had the same error because before, my Procfile was configured as explained on the Heroku guide:
from django.core.wsgi import get_wsgi_application
from dj_static import Cling
application = Cling(get_wsgi_application())
And this was causing an issue for me.

Answer 5

Try to use:
cardisle:wsgi.application
Not carlisle"."wsgi":"application