mod_wsgi (Apache)

If you are using the Apache webserver you should consider using mod_wsgi.

Installing mod_wsgi

If you don’t have mod_wsgi installed yet you have to either install it using a package manager or compile it yourself.

The mod_wsgi installation instructions cover installation instructions for source installations on UNIX systems.

If you are using ubuntu / debian you can apt-get it and activate it as follows:

# apt-get install libapache2-mod-wsgi

On FreeBSD install mod_wsgi by compiling the www/mod_wsgi port or by using pkg_add:

# pkg_add -r mod_wsgi

If you are using pkgsrc you can install mod_wsgi by compiling the www/ap2-wsgi package.

If you encounter segfaulting child processes after the first apache reload you can safely ignore them. Just restart the server.

Creating a .wsgi file

To run your application you need a yourapplication.wsgi file. This file contains the code mod_wsgi is executing on startup to get the application object. The object called application in that file is then used as application.

For most applications the following file should be sufficient:

from yourapplication import make_app
application = make_app()

If you don’t have a factory function for application creation but a singleton instance you can directly import that one as application.

Store that file somewhere where you will find it again (eg: /var/www/yourapplication) and make sure that yourapplication and all the libraries that are in use are on the python load path. If you don’t want to install it system wide consider using a virtual python instance.

Configuring Apache

The last thing you have to do is to create an Apache configuration file for your application. In this example we are telling mod_wsgi to execute the application under a different user for security reasons:

<VirtualHost *>
    ServerName example.com

    WSGIDaemonProcess yourapplication user=user1 group=group1 processes=2 threads=5
    WSGIScriptAlias / /var/www/yourapplication/yourapplication.wsgi

    <Directory /var/www/yourapplication>
        WSGIProcessGroup yourapplication
        WSGIApplicationGroup %{GLOBAL}
        Order deny,allow
        Allow from all
    </Directory>
</VirtualHost>

For more information consult the mod_wsgi wiki.