uWSGI + virtualenv 'No module named site'

Question

So this seems to be a really common problem with this setup, but I can't find any solutions that work on SO. I've setup a very new Ubuntu 15.04 server, then installed nginx, virtualenv (and -wrapper), and uWSGI (via apt-get, so globally, not inside the virtualenv).

My virtualenv is located at /root/Env/example. Inside of the virtualenv, I installed Django, then at /srv/www/example/app ran Django's startproject command with the project name example, so I have vaguely this structure:

-root
  -Env
    -example
      -bin
      -lib
-srv 
  -www
    -example
      -app
        -example
          manage.py
          -example
            wsgi.py
            ...

My example.ini file for uWSGI looks like this:

[uwsgi]
project = example

plugin = python

chdir = /srv/www/example/app/example
home = /root/Env/example
module = example.wsgi:application

master = true
processes = 5

socket = /run/uwsgi/app/example/example.socket
chmod-socket = 664
uid = www-data
gid = www-data
vacuum = true

But no matter whether I run this via uwsgi --ini /etc/uwsgi/apps-enabled/example.ini or via daemon, I get the exact same error:

Python version: 2.7.9 (default, Apr  2 2015, 15:37:21)  [GCC 4.9.2]
Set PythonHome to /root/Env/example
ImportError: No module named site

I should note that the Django project works via the built-in development server ./manage.py runserver, and that when I remove home = /root/Env/example the thing works (but is obviously using the global Python and Django rather than the virtualenv versions, which means it's useless for a proper virtualenv setup).

Can anyone see some obvious path error that I'm not seeing? As far as I can tell, home is entirely correct based on my directory structure, and everything else in the ini too, so why is it not working with this ImportError?

Answer 1

In my case, I was seeing this issue because the django app I was trying to run was written in python 3 whereas uwsgi was configured for python 2. I fixed the problem by:

1. recompiling uwsgi to support both python 2 and python 3 apps (I followed this guide)
2. adding this to my mydjangoproject_uwsgi.ini:

plugins         = python35 # or whatever you specified while compiling uwsgi 

For other folks using Django, you should also make sure you are correctly specifying the following:

# Django dir that contains manage.py
chdir           = /var/www/project/myprojectname
# Django wsgi (myprojectname is the name of your top-level project)
module          = myprojectname.wsgi:application
# the virtualenv you are using (full path)
home            = /home/ubuntu/Env/mydjangovenv
plugins         = python35