CAS with Django 1.5

I’ve posted a couple of times before about using a Central Authentication Service with Django. As I update my applications to Django v1.5, it is time to revisit the subject.

In my Django v1.3 setup, the django-cas library has served me well. However, in this later version of the framework, there are changes that break the library. The maintainer of django-cas has not yet updated their code to work with 1.5 (although there are pull requests waiting that address the issue – stay tuned).

Kansas State WildcatLuckily, another educational institution has forked the library. Our friends at Kansas State University (Go Wildcats!) have released their maintained version of django-cas on github. They have fixed the issue with the get_host() call, plus added some proxy features. Note that the fix is in a branch and not yet in a released version – currently at v0.8.5. I have installed it in my first app to be converted, and it works fine.

Installation

As far as I can tell, this K-State fork is not hosted on PyPi at this time, so I use this line in my requirements file to get the library via pip:

svn+https://github.com/kstateome/django-cas/branches/bugfix/django_1_5

This uses Subversion because that is what is available on the servers, but the git syntax will work just as well.

Configuration

K-State has provided only minimal documentation, but they link back to the original CCPC installation guide. Below are my settings.py and urls.py code. (Note that USE_CAS is a variable I define that is set True or False based on the environment.)

## django_cas settings
if USE_CAS:
    CAS_SERVER_URL = '### your server URL here ###'
    CAS_VERSION = '2'
    CAS_LOGOUT_COMPLETELY = True

    AUTHENTICATION_BACKENDS = (
        'django.contrib.auth.backends.ModelBackend',
        'cas.backends.CASBackend',
    )

    MIDDLEWARE_CLASSES += (
        'cas.middleware.CASMiddleware',
    )
## end django_cas settings

# django_cas urls
if settings.USE_CAS:
    urlpatterns = patterns('',
    ('^admin/logout/$', RedirectView.as_view(url='../../accounts/logout')), ## TODO: This could be better
    ('^admin/password_change/$',RedirectView.as_view(url='### URL to your password change service ###')),
    url(r'^accounts/login/$', 'cas.views.login',name='login'),
    url(r'^accounts/logout/$', 'cas.views.logout',name='logout'),
                       ) + urlpatterns
else:
    urlpatterns = patterns('',
    url(r'^accounts/login/$', 'django.contrib.auth.views.login',{'template_name': 'login.html'},name='login'),
                       ) + urlpatterns       
# end django_cas urls

Biggest change is that the package name changed from django-cas to cas.

Best of luck with your CAS setup!

Factory Boy and Django: Software Updates

Turn of the Century boy in a factory

I’ve been using Factory Boy in all of my tests for a while, but I hadn’t upgraded the package since setting up my development machine in December of last year. This meant I have been happily chugging along with v1.20.

Today I started the task of upgrading my applications to Django v1.5, so I ran pip install --upgrade on my requirements file. Django moved up to v1.5 just fine, but Factory Boy also jumped up to v2.11. I hadn’t noticed that some new features and several deprecations were added in v1.3, and many changes happened for v2.0.

DjangoModelFactory

The first odd behavior I noticed was that the model instances created by the factories weren’t being saved, and I also had trouble adding data to ManyToMany relationships even after I explicitly saved them. Turns out there was a major change to the Factory class. Rather than use that generic class, we are now being directed to use DjangoModelFactory.

The error I was seeing was a recursion problem, so it took a while to track down.

Sequence

Next, all of my Sequence calls were failing – telling me that I couldn’t use a string operation on a type of ‘int’. In this case the problem was that the default data type for a sequence was changed to ‘int’. Since ‘str’ was the former default (although not necessarily documented), my solution was to declare the type as ‘str’.

name = factory.Sequence(lambda n: 'Location ' + n, str)

I’m a big fan of this package for tests, and I am glad that it is a very active project. Read through the change log for more info on these and many other updates.

I promise to do a better job of keeping up with the changes.