From DreamHost

Passenger is best known for being used with Ruby on Rails applications. However, it's got another trick up its sleeve... it can also serve up Python web applications which use the WSGI interface, including any application which uses the Django framework! Since Passenger allows your application to temporarily reside in memory while it is being actively used, it will allow your site to respond significantly faster than is otherwise possible.

Note that Passenger's WSGI support is currently considered a "proof of concept"[1]. It currently seems to work reasonably well; nevertheless, you should probably have a backup plan ready (such as Python FastCGI) in case you run into problems.

Contents 1 Setting up Passenger WSGI 1.1 Passenger WSGI and Django 1.2 Passenger WSGI and virtualenv 2 See also

Setting up Passenger WSGI

To start an example Python site using Passenger WSGI, your first step should be to configure the domain to use Passenger in the Manage Domains section of the web panel. Note that the document root must end in "/public" for a Passenger application - this directory will be used to serve static media.

Once you have set the domain to use Passenger, create a file called passenger_wsgi.py in the folder above the document root (i.e, if you set your document root to /home/username/example.com/public, you'd put this file at /home/username/example.com/passenger_wsgi.py). This file must export a WSGI server with the name application. Here's a minimal example:

def application(environ, start_response):
    write = start_response('200 OK', [('Content-type', 'text/plain')])
    return ["Hello, world!"]

This application will return a text file with the content "Hello, world!" for any request.

Passenger WSGI and Django

See Django for instructions on how to configure Passenger to run Django.

Passenger WSGI and virtualenv

As Passenger loads your passenger_wsgi.py into a special wrapper (currently /dh/passenger/lib/passenger/wsgi/request_handler.py, although this may change), you cannot directly select what Python interpreter is used to run your application. However, you can switch interpreters at runtime by adding the following code to the beginning of your passenger_wsgi.py:

import sys, os
INTERP = "/home/username/local/bin/python"
if sys.executable != INTERP: os.execl(INTERP, INTERP, *sys.argv)

Set INTERP to the Python interpreter which you wish to use instead of the default.

See also

• Passenger
• Python
• Python FastCGI (an alternative approach)