Django language select on Heroku using Gunicorn doesn’t work

Question

I’m running a Django app on Heroku and have installed this piece of code: https://github.com/st4lk/django-solid-i18n-urls

It works just as expected on the Django built-in server, but when deployed to Heroku, I’m starting to see some really nasty problems.

I have Gunicorn running with multiple workers and if I use this code, the language preference starts to work randomly (I guess it depends which instance the request goes against).

For example if I have EN as the default (non-prefixed url) and DE as the second language, everything is working fine if I just browse the / urls. Now, if I switch to /de/ (manually enter URL or switch from the Django language switcher), the main / url starts to work intermittently – if I keep refreshing the page, I get either a 404 or the page in DE. But there’s no way to switch it back to using EN completely again. Same happens with all the other URLs as well, I get either a 404 or the corresponding page in DE. And there’s no way to force it back to EN, even from the Django’s set_language view.

If I never touch the /de/ urls, it works all very well without the prefixed URLs.

Does anyone have any ideas how to get this working also on Heroku and Gunicorn?

Answer 1

It turns out Gunicorn and the middleware override works fine, problem was with another piece of custom middleware.