SLP: Django: Deployment

Go up to the main SLP documents page (md)

This page is for how to deploy your Django apps on an Ubuntu server -- specifically, Ubuntu 14.04. This is not needed for your local development, as you can run python runserver to test it out locally, or test it out on the course server provided. However, if you do want to get it running through Apache, read on...

Installing packages

To install Django on your own system, under Ubuntu 14.04, just enter sudo apt-get install python-django python-mysqldb, and it will do the rest. As of the writing of this tutorial (Aug 31, 2014), this installs Python version 2.7.6 and Django version 1.6.1.

About installing the wsgi module, and for python 2/3...

Configuring Apache

This assumes Apache version 2.4; if you are using version 2.2, then the syntax for this is quite different (some of those differences are described below).

This part specifically deals with configuring multiple django apps on the same web server, as that is what is needed for this course. For each django app, the following 8 lines need to be added to /etc/apache2/sites-available/000-default.conf, right above the end </VirtualHost> line:

Alias /django/user/static /home/slp/user/mysite/static
<Directory /home/slp/user/mysite/static>
  Require all granted
WSGIScriptAlias /django/user /home/slp/user/mysite/mysite/
WSGIDaemonProcess user python-path=/home/slp/user/mysite
<Location /django/user>
  WSGIProcessGroup user
<Directory /home/slp/user/mysite/mysite>
    Require all granted

A bunch of notes:

Sine there are going to be many users in a system, it will be easier to put this in a separate file (say, called /etc/apache2/django.conf), and insert a Include django.conf line in /etc/apache2/sites-available/000-default.conf (also right above the </VirtualHost> line).

If you are enabling these through SSL, there is a slight change. When Apache restarts (or reloads), the default (i.e., non-SSL) site is brought up first, followed by the SSL site. As the daemon process has already been declared in 000-default.conf (for the non-SSL site), it will cause an error to declare it again for the SSL site. Thus, the SSL version should not have the WSGIDaemonProcess line; all the other lines remain the same. This implies that the file included from default-ssl.conf will be a different one than the one included from 000-default.ssl.

Managing multiple users

The issue with the WSGI module is that if any one of the WSGI files it is configured with does not exist, then all of the WSGI modules don't work. This means you can't pre-generate the list of WSGI links for a class, as none of them will work until everybody has it set up, which is not viable.

To work around this, you can see the wsgi-admin.cpp (src), which will allow students to register and remove their WSGI apps. It will update the necessary Apache configuration files, and then reload the web server. It can also be used just to do the regeneration and reloading -- and if a file is not found (or is not valid), then it is excluded from the configuration files. Installation is tricky, but the process is described in the comments at the top of that file. The directions for how to use it can be found on the Django getting started (md) page.