Setting up a cron job to run a Django management command in a Python virtualenv

Posted March 25, 2010. Tagged coding, django, and linux.

For the Activity (update: activity removed from redesigned site) section of this site, I wrote a Django management command. The command connects to the various social network sites being tracked, fetches my activity, and then creates database items. By caching the items in my own database, I avoid the terrible performance that would come from fetching them anytime someone visits my site.

The only downside is that this command has to be run whenever I want the data updated. To handle this, I set up a cron job to run this command every hour. Worst case, the activity shown on the site is nearly an hour stale, but the performance and reliability are worth it.

Since I use virtualenv to set up an isolated Python environment to host this site, the command I needed to use is a little more complicated than normal. I figured I’d put that here for reference:

cd <path_to_project>
~/.virtualenvs/<venv_name>/bin/python <path_to_project>/manage.py updateactivities

Note that, since my project does not happen to be on the PYTHONPATH, I need to switch into the directory first before running the management command.