One piece of increasingly conventional wisdom when developing Django applications is that your
settings.py file ought to conclude with some variant of
try: from local_settings import * except ImportError: pass
the idea being that you can put a
local_settings.py file on each server with the appropriate information for that site.
I would challenge that this approach is wrong. By definition, you cannot put
local_settings.py in version control, which means that a critical part of your infrastructure—how to deploy the thing—is not getting versioned. At the same time, using the same settings for your development box and your deployment box is unreasonable, and usually stupid.
After being unhappy with several solutions, including the one Simon Willison advocated in his excellent Django Heresies talk (which has a pile of other great tips as well), I stole a bit from everything I’d seen to come up with what I believe is my own design.
Rather than importing from
local_settings, I decided to make
settings be a full-blown module and use some Python magic. First, kill
settings.py and make a
settings directory. Then, add the following to
import socket hostname = socket.gethostname().replace('.', '_').lower() try: custom_settings = __import__(hostname) __all__.append(custom_settings) except ImportError: from development import *
While this is definitely somewhat magical, it’s not too hard to follow: grab the hostname, convert it into a more Python-like form, and attempt to import it. If that succeeds, add it to
__all__ for export. Otherwise, default to the
With this change, we can now have a file for each machine we intend to deploy on, named after the machine, put into the
settings directory, and it’ll be used automatically. Now, you’ve got the best of both worlds: site-specific configuration, managed by source control.
There’s one little caveat here that may or may not bother you: one of the data that generally go into
local_settings.py is your database password, which you probably do not want in version control. Thankfully, that’s trivial to work around: in a non-version-controlled file on the server, create a
settings/passwords.py file which contains only relevant passwords for that system. Then, at the tail end of that site’s settings file, add:
from passwords import *
It’s the same trick we used to use for
local_settings.py, except that now, the only thing that’s not version-controlled is your password. Everything else—memcached settings, custom middleware and template directories,
ADMINS lists, and so on—will be safely in your VCS of choice.