LTI, Juniper and language preferences?

sambapete · February 12, 2020, 6:48pm

I’ve encountered a strange bug while investigating a problem we had while testing LTI on open-release/juniper.alpha1

I imported a course that has an LTI ressource and that previously worked under ironwood.

I used http://ltiapps.net/test/tc.php while trying to access that course.

I got the following error messages about the language preference of the course in /edx/var/log/lms/edx.log:

gist.github.com

https://gist.github.com/sambapete/09139d73deeddd44918d0654b72d9ed7

gistfile1.txt

Feb 12 18:25:07 ip-10-0-0-10 [service_variant=lms][py.warnings][env:sandbox] WARNING [ip-10-0-0-10  15319] [user None] [backends.py:37] - /edx/app/edxapp/venvs/edxapp/lib/python3.5/site-packages/django/contrib/auth/__init__.py:116: UserWarning: No request passed to the backend, unable to rate-limit. Username was 'EzhsCbCSn3vBa3y7UhGRSzC3wfr2c4'
  return backend.authenticate(*args, **credentials)
Feb 12 18:25:07 ip-10-0-0-10 [service_variant=lms][audit][env:sandbox] INFO [ip-10-0-0-10  15319] [user 17] [models.py:2387] - Login success - user.id: 17
Feb 12 18:25:07 ip-10-0-0-10 [service_variant=lms][py.warnings][env:sandbox] WARNING [ip-10-0-0-10  15319] [user 17] [__init__.py:1565] - /edx/app/edxapp/venvs/edxapp/lib/python3.5/site-packages/pkg_resources/__init__.py:1146: DeprecationWarning: Use of .. or absolute path in a resource path is not allowed and will raise exceptions in a future release.
  self, resource_name
Feb 12 18:25:07 ip-10-0-0-10 [service_variant=lms][openedx.core.djangoapps.user_api.helpers][env:sandbox] WARNING [ip-10-0-0-10  15319] [user 17] [helpers.py:68] - A handled error occurred when calling 'set_user_preference' with arguments '(<User: EzhsCbCSn3vBa3y7UhGRSzC3wfr2c4>, 'pref-lang', 'en')' and keyword arguments '{}': PreferenceValidationError({'pref-lang': {'user_message': "Value 'en' is not valid for user preference 'pref-lang'.", 'developer_message': 'Value \'en\' not valid for preference \'pref-lang\': {\'user\': [\'Invalid pk "17" - object does not exist.\']}'}},)
Feb 12 18:25:07 ip-10-0-0-10 [service_variant=lms][root][env:sandbox] ERROR [ip-10-0-0-10  15319] [user 17] [signals.py:23] - Uncaught exception from <class 'django.core.handlers.wsgi.WSGIHandler'>
Traceback (most recent call last):
  File "/edx/app/edxapp/venvs/edxapp/lib/python3.5/site-packages/django/core/handlers/base.py", line 131, in get_response
    response = middleware_method(request, response)

This file has been truncated. show original

What I find strange is that the anonymous user created by the LTI process needs a language preference? I don’t remember ever setting a language preference for LTI users in the past.

I also noticed that [user 17] in the error logs has not been created in the auth_user table in mysql.

If I try to access the course again, it goes to [user 18] as expected, but I get the same error messages and stil no user created in auth_user.

Anybody has an explanation for this? Or is there a big LTI issue with juniper.alpha1 ?

As we have a lot of our courses being used as LTI ressources by other LMS, this could be a major issue for us.

By the way, the only things modified from a default single-server juniper.alpha1 installation are the entries in /edx/etc/lms.yml.

Under FEATURES: we added:
ENABLE_LTI_PROVIDER: true

Under JWT_AUTH: we modified:
JWT_ISSUER
ISSUER
JWT_PRIVATE_SIGNING_JWK
JWT_PUBLIC_SIGNING_JWK_SET
JWT_SIGNING_ALGORITHM

It is as close to a vanilla installation as can be…

The migration were also run in order to create the 4 LTI tables in the database edxapp in mysql.

/edx/app/edxapp/reload_lms_config.sh was also ran in order to reload the LMS configuration.

sambapete · February 12, 2020, 11:53pm

Just for the sake of it, I modified LANGUAGE_CODE in /edx/etc/lms.yml from en to fr.

My site and my error logs are in French as expected. Nonetheless, it still complains about ‘en’ not being a valid preference for pref-lang for the user id 17 that it is trying to create as a result of accessing the ressource via LTI.

openedx.core.djangoapps.user_api.errors.PreferenceValidationError: {‘pref-lang’: {‘user_message’: “La valeur ‘en’ n’est pas valide pour la préférence utilisateur’pref-lang’.”, ‘developer_message’: 'Value ‘en’ not valid for preference ‘pref-lang’: {‘user’: ['Clé primaire “17” non valide - l\‘objet n\‘existe pas.’]}’}}

I am still unsure why it tries to validate the language preference of an anonymized user created for LTI purposes. Any idea?

I also created a Community Reported Issue as https://openedx.atlassian.net/browse/CRI-179