Remove old user replication code.

- we don't use it, and if we do want to change the arch, we should have a proper central user info service.

common/djangoapps/student/models.py

@@ -704,167 +704,3 @@ def update_user_information(sender, instance, created, **kwargs):
         log.error(unicode(e))
         log.error("update user info to discussion failed for user with id: " + str(instance.id))
 
-
-########################## REPLICATION SIGNALS #################################
-# @receiver(post_save, sender=User)
-def replicate_user_save(sender, **kwargs):
-    user_obj = kwargs['instance']
-    if not should_replicate(user_obj):
-        return
-    for course_db_name in db_names_to_replicate_to(user_obj.id):
-        replicate_user(user_obj, course_db_name)
-
-
-# @receiver(post_save, sender=CourseEnrollment)
-def replicate_enrollment_save(sender, **kwargs):
-    """This is called when a Student enrolls in a course. It has to do the
-    following:
-
-    1. Make sure the User is copied into the Course DB. It may already exist
-       (someone deleting and re-adding a course). This has to happen first or
-       the foreign key constraint breaks.
-    2. Replicate the CourseEnrollment.
-    3. Replicate the UserProfile.
-    """
-    if not is_portal():
-        return
-
-    enrollment_obj = kwargs['instance']
-    log.debug("Replicating user because of new enrollment")
-    for course_db_name in db_names_to_replicate_to(enrollment_obj.user.id):
-        replicate_user(enrollment_obj.user, course_db_name)
-
-    log.debug("Replicating enrollment because of new enrollment")
-    replicate_model(CourseEnrollment.save, enrollment_obj, enrollment_obj.user_id)
-
-    log.debug("Replicating user profile because of new enrollment")
-    user_profile = UserProfile.objects.get(user_id=enrollment_obj.user_id)
-    replicate_model(UserProfile.save, user_profile, enrollment_obj.user_id)
-
-
-# @receiver(post_delete, sender=CourseEnrollment)
-def replicate_enrollment_delete(sender, **kwargs):
-    enrollment_obj = kwargs['instance']
-    return replicate_model(CourseEnrollment.delete, enrollment_obj, enrollment_obj.user_id)
-
-
-# @receiver(post_save, sender=UserProfile)
-def replicate_userprofile_save(sender, **kwargs):
-    """We just updated the UserProfile (say an update to the name), so push that
-    change to all Course DBs that we're enrolled in."""
-    user_profile_obj = kwargs['instance']
-    return replicate_model(UserProfile.save, user_profile_obj, user_profile_obj.user_id)
-
-
-######### Replication functions #########
-USER_FIELDS_TO_COPY = ["id", "username", "first_name", "last_name", "email",
-                       "password", "is_staff", "is_active", "is_superuser",
-                       "last_login", "date_joined"]
-
-
-def replicate_user(portal_user, course_db_name):
-    """Replicate a User to the correct Course DB. This is more complicated than
-    it should be because Askbot extends the auth_user table and adds its own
-    fields. So we need to only push changes to the standard fields and leave
-    the rest alone so that Askbot changes at the Course DB level don't get
-    overridden.
-    """
-    try:
-        course_user = User.objects.using(course_db_name).get(id=portal_user.id)
-        log.debug("User {0} found in Course DB, replicating fields to {1}"
-                  .format(course_user, course_db_name))
-    except User.DoesNotExist:
-        log.debug("User {0} not found in Course DB, creating copy in {1}"
-                  .format(portal_user, course_db_name))
-        course_user = User()
-
-    for field in USER_FIELDS_TO_COPY:
-        setattr(course_user, field, getattr(portal_user, field))
-
-    mark_handled(course_user)
-    course_user.save(using=course_db_name)
-    unmark(course_user)
-
-
-def replicate_model(model_method, instance, user_id):
-    """
-    model_method is the model action that we want replicated. For instance,
-                 UserProfile.save
-    """
-    if not should_replicate(instance):
-        return
-
-    course_db_names = db_names_to_replicate_to(user_id)
-    log.debug("Replicating {0} for user {1} to DBs: {2}"
-              .format(model_method, user_id, course_db_names))
-
-    mark_handled(instance)
-    for db_name in course_db_names:
-        model_method(instance, using=db_name)
-    unmark(instance)
-
-
-######### Replication Helpers #########
-
-
-def is_valid_course_id(course_id):
-    """Right now, the only database that's not a course database is 'default'.
-    I had nicer checking in here originally -- it would scan the courses that
-    were in the system and only let you choose that. But it was annoying to run
-    tests with, since we don't have course data for some for our course test
-    databases. Hence the lazy version.
-    """
-    return course_id != 'default'
-
-
-def is_portal():
-    """Are we in the portal pool? Only Portal servers are allowed to replicate
-    their changes. For now, only Portal servers see multiple DBs, so we use
-    that to decide."""
-    return len(settings.DATABASES) > 1
-
-
-def db_names_to_replicate_to(user_id):
-    """Return a list of DB names that this user_id is enrolled in."""
-    return [c.course_id
-            for c in CourseEnrollment.objects.filter(user_id=user_id)
-            if is_valid_course_id(c.course_id)]
-
-
-def marked_handled(instance):
-    """Have we marked this instance as being handled to avoid infinite loops
-    caused by saving models in post_save hooks for the same models?"""
-    return hasattr(instance, '_do_not_copy_to_course_db') and instance._do_not_copy_to_course_db
-
-
-def mark_handled(instance):
-    """You have to mark your instance with this function or else we'll go into
-    an infinite loop since we're putting listeners on Model saves/deletes and
-    the act of replication requires us to call the same model method.
-
-    We create a _replicated attribute to differentiate the first save of this
-    model vs. the duplicate save we force on to the course database. Kind of
-    a hack -- suggestions welcome.
-    """
-    instance._do_not_copy_to_course_db = True
-
-
-def unmark(instance):
-    """If we don't unmark a model after we do replication, then consecutive
-    save() calls won't be properly replicated."""
-    instance._do_not_copy_to_course_db = False
-
-
-def should_replicate(instance):
-    """Should this instance be replicated? We need to be a Portal server and
-    the instance has to not have been marked_handled."""
-    if marked_handled(instance):
-        # Basically, avoid an infinite loop. You should
-        log.debug("{0} should not be replicated because it's been marked"
-                  .format(instance))
-        return False
-    if not is_portal():
-        log.debug("{0} should not be replicated because we're not a portal."
-                  .format(instance))
-        return False
-    return True