This is going to be a short post. It deals with a specific issue I just ran into.
I had an old project that I had started. I made the decision to start up development on it again. The project was running Django 1.4.3. There were some sites I had done in 1.5, but I had not migrated a site yet. I jumped into my requirements.txt and changed the line to 1.5.2 the most current stable version of Django.
The migration was not too difficult and I decide to push it to Heroku. After pip installs the updated version of Django I load up the app and I get a 500 status code. I double check my local version and I don’t get the error. I push out a change to make Heroku run DEBUG=True (running the local as DEBUG=False would have been too easy). The site works.
I had not setup any logging as there was not much code, so I setup a quick log to console. I notice that it is complaining about the ALLOWED_HOSTS setting.
Django released a security update in February 2013 for 1.4.4 (just missed it) that requires the ALLOWED_HOSTS to be set if DEBUG=False. All you have to do is set it to your FQDN. I went ahead and set it for my local development site and Heroku.
Hopefully this will save someone some time.