How do I use a conda environment with mod_wsgi?

Question

My first post, and I'm new to both Python and Apache, so please go easy on me. I have a Python web application in a conda environment that serves up content just fine using Flask. Now I need to serve everything with Apache instead of Flask. I can get Apache to run Python with mod_wsgi, but only with virtualenv. I tried installing virtualenv with Anaconda, but I received a warning that such a setup is unsupported and not recommended. So my question is this:

How do I set up Apache to run my application in a conda environment?

Here, there's a section on working with virtual environments, and it says I need to enter a line into my wsgi file showing where to find activate_this.py. A virtualenv virtual environment has activate_this.py, but a conda environment does not. It seems that without the right instructions for activating the virtual environment, I'm just getting error 500 in my browser and "Import error: no module named flask" in my httpd error_log.

This is in my httpd.conf file:

<VirtualHost *:80>
     DocumentRoot /var/www
     WSGIScriptAlias / var/www/tsm.wsgi
     <Directory /var/www/tsm>
     Order allow,deny
     Allow from all
     </Directory>
</VirtualHost>

And here is tsm.wsgi:

import sys
import site
site.addsitedir('~/.conda/envs/tsm/lib/python2.7/site-packages')
sys.path.insert(0, '/var/www/tsm/server/time_series_machine')
sys.stdout = sys.stderr
from app import app as application

Any ideas? Thanks for any help you can provide.

Answer 1

Your mod_wsgi would need to be compiled against Anaconda Python to start with and not your system Python. In other words you cannot use the system supplied mod_wsgi packages but would need to compile it yourself. Then follow what it says in:

• http://blog.dscpl.com.au/2014/09/using-python-virtual-environments-with.html

That is, use daemon mode and use the python-home option to WSGIDaemonProcess.

Do note that there have been reports suggesting that Anaconda Python is broken in some way and will not work with systems that want to embed Python. So may not work anyway.

BTW, you cannot use '~' in the path in your WSGI script file anyway with the way you were doing it. It would not be expanded to be the home directory. But then, follow that post and you will not need that.

Answer 2

I'm late to the party on this but I was having the same problem. For what its worth, I didn't have to recompile anything and was able to get this to work by including something like this in my VirtualHost configuration using the system-installed mod_wsgi:

WSGIDaemonProcess mysite python-path=/path/to/anaconda2/lib/python2.7/site-packages

Note that this points to the site-packages directory.

Answer 3

To add to @dino's answer, you can also install mod_wsgi into your root conda environment:

# Instal `mod_wsgi`
$ pip install mod_wsgi

# Find the full path to installed `mod_wsgi`
$ which mod_wsgi-express

# Install and register the `mod_wsgi` module with Apache
$ sudo /full/path/to/installed/mod_wsgi-express install-module

You can then create conda environments for multiple sites:

# Create 3 conda environments
conda create -n mysite1 python django
conda create -n mysite2 python django
conda create -n mysite3 python django

And set WSGIDaemonProcess in the Apache site configuration file to use the appropriate environment for each site:

# /etc/apache2/sites-enabled/mysite1.conf
WSGIDaemonProcess mysite1 python-path=/path/to/anaconda3/envs/mysite1/lib/python3.5/site-packages

# /etc/apache2/sites-enabled/mysite2.conf
WSGIDaemonProcess mysite2 python-path=/path/to/anaconda3/envs/mysite2/lib/python3.5/site-packages

# /etc/apache2/sites-enabled/mysite3.conf
WSGIDaemonProcess mysite3 python-path=/path/to/anaconda3/envs/mysite3/lib/python3.5/site-packages