Split modulestore persists data in three MongoDB "collections": course_index (list of courses and the current version of each), structure (outline of the courses, and some XBlock fields), and definition (other XBlock fields). While "structure" and "definition" data can get very large, which is one of the reasons MongoDB was chosen for modulestore, the course index data is very small.
This commit starts writing course indexes (active_versions) to both MySQL and Mongo, but continues to read from MongoDB only.
By moving course index data to MySQL / a django model, we get these advantages:
* Full history of changes to the course index data is now preserved
* Includes a django admin view to inspect the list of courses and libraries
* It's much easier to "reset" a corrupted course to a known working state, by using the simple-history revert tools from the django admin.
* The remaining MongoDB collections (structure and definition) are essentially just used as key-value stores of large JSON data structures. This paves the way for future changes that allow migrating courses one at a time from MongoDB to S3, and thus eliminating any use of MongoDB by split modulestore, simplifying the stack.
Split modulestore persists data in three MongoDB "collections": course_index (list of courses and the current version of each), structure (outline of the courses, and some XBlock fields), and definition (other XBlock fields). While "structure" and "definition" data can get very large, which is one of the reasons MongoDB was chosen for modulestore, the course index data is very small.
By moving course index data to MySQL / a django model, we get these advantages:
* Full history of changes to the course index data is now preserved
* Includes a django admin view to inspect the list of courses and libraries
* It's much easier to "reset" a corrupted course to a known working state, by using the simple-history revert tools from the django admin.
* The remaining MongoDB collections (structure and definition) are essentially just used as key-value stores of large JSON data structures. This paves the way for future changes that allow migrating courses one at a time from MongoDB to S3, and thus eliminating any use of MongoDB by split modulestore, simplifying the stack.
Does 3 things:
(1) Use django for modulestore tests
(2) Use normal LMS settings for modulestore tests instead of openedx/tests/settings.py
(3) Simplify some TestCase subclasses by converting them to use ModuleStoreTestCase
Details and rationale:
(1) Currently parts of the modulestore test suite are designed to run "without django", although there is still a lot of django functionality imported at times, and many of the tests do in fact use django. But for the upcoming PR #27565 (moving split's course indexes from MongoDB to MySQL), we will need to always have Django enabled. So this commit paves the way for that change.
(2) The previous tests that did use Django used a special settings file, openedx/tests/settings.py which made some debugging confusing because those tests had quite different django settings than other tests. This change deletes that file and runs the tests using the LMS test settings.
(3) The test suite also contains many different ways of initializing and testing a modulestore, with significant differences in their configuration, and also a lot of repetition. I find this makes understanding, debugging and writing tests more difficult. So this commit also reduces the number of different "test case using modulestore" base classes:
* Simplifies MixedWithOptionsTestCase and MixedSplitTestCase by making them simple subclasses of ModuleStoreTestCase.
* Removes PureModulestoreTestCase.
* Generate common/djangoapps import shims for LMS
* Generate common/djangoapps import shims for Studio
* Stop appending project root to sys.path
* Stop appending common/djangoapps to sys.path
* Import from common.djangoapps.course_action_state instead of course_action_state
* Import from common.djangoapps.course_modes instead of course_modes
* Import from common.djangoapps.database_fixups instead of database_fixups
* Import from common.djangoapps.edxmako instead of edxmako
* Import from common.djangoapps.entitlements instead of entitlements
* Import from common.djangoapps.pipline_mako instead of pipeline_mako
* Import from common.djangoapps.static_replace instead of static_replace
* Import from common.djangoapps.student instead of student
* Import from common.djangoapps.terrain instead of terrain
* Import from common.djangoapps.third_party_auth instead of third_party_auth
* Import from common.djangoapps.track instead of track
* Import from common.djangoapps.util instead of util
* Import from common.djangoapps.xblock_django instead of xblock_django
* Add empty common/djangoapps/__init__.py to fix pytest collection
* Fix pylint formatting violations
* Exclude import_shims/ directory tree from linting
Some tests were still relying on deprecated
WaffleSwitchNamespace.override method, which was working before because
we were importing WaffleSwitchNamespace from waffle_utils.__init__. This
no longer works after we import WaffleSwitchNamespace from edx-toggles.
This change will prevent Library Content from being marked as
complete on view and the corresponding version bump to
edx-completion contains code that will start looking at the
children of the library content for completeness.
Some notes:
* The completion API was pulled out into a new repo, but left behind a
url() entry. That entry used a different namespace than the
pulled-out repo, so I had to fix the one place we used the namespace.
* Two urls couldn't be anchored because they broke tests:
url(r'users/(?P<user_id>\w+)/followed$', views.followed_threads, name='followed_threads'),
url(r'users/(?P<user_id>\w+)$', views.user_profile, name='user_profile'),
