Crontab Django Virtualenv

andywar65

I'm new to crontab. I'd like to trigger a Django management command on a schedule. My Django project is installed the Opalstack way, with uwsgi and a virtualenv. I've read on the net that you have to start the virtualenv using source, so the crontab would look something like this:
SHELL=/bin/bash */15 * * * * source /home/<username>/apps/<app_name>/env/bin/activate && cd /home/<username>/apps/<app_name>/<project_name> && python manage.py <command_name>
Before breaking something I'd like your advice on the subject.
Thank you
A

sean

You usually don't need to activate a virtualenv to use it in a cron job.

You should be able to run the job by explicitly calling the python executable that is in your virtualenv, like so:

SHELL=/bin/bash
*/15 * * * * cd /home/<username>/apps/<app_name>/<project_name> && /home/<username>/apps/<app_name>/env/bin/python manage.py <command_name>

andywar65

Got it working thanks to houdinihound's suggestion of adding MAILTO: it was just a typo! At the end of the line I added > /dev/null 2>&1 but I forgot the >. The error message I got was: manage.py fetch_messages: error: unrecognized arguments: /dev/null.
I used sean's format: */15 * * * * cd /home/<username>/apps/<app_name>/<project_name> && /home/<username>/apps/<app_name>/env/bin/python manage.py <command_name>, so there is definitely no need to activate a venv. SHELL=/bin/bash seems useless.
Thank you all!

andywar65

Unfortunately it doesn't work either way. If I enter the shell, activate the venv and run the command manually all works perfectly.

sean

andywar65 what sort of error or problem do you see? If you'd rather not share that here then please feel free to email support@ with the details.

houdinihound

@andywar65 You said you're new to crontab. Quick tip: add these two lines to the top of your crontab and then any error output from the cron job will be emailed to you which may yield a clue as to what is going wrong.

MAILTO="sendto@wherever.com"
MAILFROM="address@yourdomain.com"

# This executes a script using my virtualenv python installation.
*/15 * * * * /home/my_username/my_virtenvs_dir/my_virt_env/bin/python3 /home/my_username/my_virtenvs_dir/my_virt_env/lib/my_scripts/script.py

Also included, a line in my crontab that executes a python script every 15 minutes within one of my virtual environments, just the directory names changed.

HTH,