Models from apps using sentry.apps entrypoint are never synced

[andialbrecht]

If an app registers itself using sentry.apps entrypoint and if the app has it's own models, the models of this app are not seen when "sentry upgrade" or "sentry start" is run. Hence there's no way to get those models into the database, except when adding the app manually to INSTALLED_APPS.

The culprit is that sentry.utils.runner:initialize_app calls skip_migration_if_applied and at some point during the initialization (or getitem) of Migrations(app_name)[name] Django populates the app cache (in django.db.models.loading). But since initialize_app is called as a callback in logan.importer.LoganLoader before the settings module is returned and properly registered in Python's import machinery all from django.conf import settings imports that happen in south will import the unmodified settings.

You can easily see what happens by adding

from django.conf import settings as django_settings
print(django_settings.INSTALLED_APPS, settings.INSTALLED_APPS)

somewhere at the top of skip_migration_if_applied (stupid prints, I know, but it illustrates the issue :) ).

As far as I understand the code the behavior that the callback function passed to LoganLoader relies on code that imports Django settings is wrong.

[dcramer]

I believe this is now fixed (accidentally) when we added the on_configure hook.