log all social auth creation failures (#21470)

logging on social auth creation failures

lms/djangoapps/program_enrollments/signals.py

@@ -26,20 +26,34 @@ def _listen_for_lms_retire(sender, **kwargs):  # pylint: disable=unused-argument
 
 
 @receiver(post_save, sender=UserSocialAuth)
-def matriculate_learner(sender, instance, created, **kwargs):  # pylint: disable=unused-argument
+def listen_for_social_auth_creation(sender, instance, created, **kwargs):  # pylint: disable=unused-argument
     """
-    Post-save signal to update any waiting program enrollments with a user,
-    and enroll the user in any waiting course enrollments.
-
-    In most cases this will just short-circuit. Enrollments will only be updated
-    for a SAML provider with a linked organization.
+    Post-save signal that will attempt to link a social auth entry with waiting enrollments
     """
     if not created:
         return
 
     try:
-        user = instance.user
-        provider_slug, external_user_key = instance.uid.split(':')
+        matriculate_learner(instance.user, instance.uid)
+    except Exception as e:
+        logger.warning(
+            u'Unable to link waiting enrollments for user %s, social auth creation failed: %s',
+            instance.user.id,
+            e,
+        )
+        raise
+
+
+def matriculate_learner(user, uid):
+    """
+    Update any waiting program enrollments with a user,
+    and enroll the user in any waiting course enrollments.
+
+    In most cases this will just short-circuit. Enrollments will only be updated
+    for a SAML provider with a linked organization.
+    """
+    try:
+        provider_slug, external_user_key = uid.split(':')
         authorizing_org = SAMLProviderConfig.objects.current_set().get(slug=provider_slug).organization
 
         if not authorizing_org:

lms/djangoapps/program_enrollments/tests/test_signals.py

@@ -358,3 +358,27 @@ class SocialAuthEnrollmentCompletionSignalTest(CacheIsolationTestCase):
                         error_tmpl.format(self.user.id, program_course_enrollments[0].id, 'something has gone wrong')
                     )
                 )
+
+    def test_log_on_unexpected_exception(self):
+        """
+        unexpected errors as part of the account linking process should be logged and re-raised
+        """
+        program_enrollment = self._create_waiting_program_enrollment()
+        self._create_waiting_course_enrollments(program_enrollment)
+
+        with mock.patch('lms.djangoapps.program_enrollments.models.ProgramCourseEnrollment.enroll') as enrollMock:
+            enrollMock.side_effect = Exception('unexpected error')
+            with LogCapture(logger.name) as log:
+                with self.assertRaisesRegex(Exception, 'unexpected error'):
+                    UserSocialAuth.objects.create(
+                        user=self.user,
+                        uid='{0}:{1}'.format(self.provider_slug, self.external_id),
+                    )
+                error_tmpl = u'Unable to link waiting enrollments for user {}, social auth creation failed: {}'
+                log.check_present(
+                    (
+                        logger.name,
+                        'WARNING',
+                        error_tmpl.format(self.user.id, 'unexpected error')
+                    )
+                )