From 99837dfaf7a21927a8e1cf1f544fdcbb9bb69bf3 Mon Sep 17 00:00:00 2001
From: brianjbuck-wgu <brian.buck@wgu.edu>
Date: Thu, 5 Mar 2026 14:26:17 -0700
Subject: [PATCH] fix: log warning when INSTRUCTOR_MICROFRONTEND_URL is unset
 (#38000)

---
 .../instructor/tests/test_api_v2.py           | 19 +++++++++++++++++++
 .../instructor/views/serializers_v2.py        |  8 ++++++++
 lms/envs/devstack.py                          |  1 +
 3 files changed, 28 insertions(+)

diff --git a/lms/djangoapps/instructor/tests/test_api_v2.py b/lms/djangoapps/instructor/tests/test_api_v2.py
index 79e55dfdc6..61797e1e93 100644
--- a/lms/djangoapps/instructor/tests/test_api_v2.py
+++ b/lms/djangoapps/instructor/tests/test_api_v2.py
@@ -494,6 +494,25 @@ class CourseMetadataViewTest(SharedModuleStoreTestCase):
         self.assertIn('course_errors', response.data)
         self.assertIsInstance(response.data['course_errors'], list)
 
+    @patch('lms.djangoapps.instructor.views.serializers_v2.settings.INSTRUCTOR_MICROFRONTEND_URL', None)
+    def test_tabs_log_warning_when_mfe_url_not_set(self):
+        """
+        Test that a warning is logged when INSTRUCTOR_MICROFRONTEND_URL is not set.
+        """
+        with self.assertLogs('lms.djangoapps.instructor.views.serializers_v2', level='WARNING') as cm:
+            tabs = self._get_tabs_from_response(self.staff)
+
+        self.assertTrue(
+            any('INSTRUCTOR_MICROFRONTEND_URL is not set' in msg for msg in cm.output)
+        )
+        # Tab URLs should use empty string as base, not "None"
+        for tab in tabs:
+            self.assertFalse(tab['url'].startswith('None'), f"Tab URL should not start with 'None': {tab['url']}")
+            self.assertTrue(
+                tab['url'].startswith('/instructor/'),
+                f"Tab URL should start with '/instructor/': {tab['url']}"
+            )
+
     def test_pacing_self_for_self_paced_course(self):
         """
         Test that pacing is 'self' for self-paced courses.
diff --git a/lms/djangoapps/instructor/views/serializers_v2.py b/lms/djangoapps/instructor/views/serializers_v2.py
index 6251dc5c50..04c97450b2 100644
--- a/lms/djangoapps/instructor/views/serializers_v2.py
+++ b/lms/djangoapps/instructor/views/serializers_v2.py
@@ -5,6 +5,8 @@ These serializers handle data validation and business logic for instructor dashb
 Following REST best practices, serializers encapsulate most of the data processing logic.
 """
 
+import logging
+
 from django.conf import settings
 from django.utils.html import escape
 from django.utils.translation import gettext as _
@@ -33,6 +35,8 @@ from xmodule.modulestore.django import modulestore
 
 from .tools import get_student_from_identifier, parse_datetime, DashboardError
 
+log = logging.getLogger(__name__)
+
 
 class CourseInformationSerializerV2(serializers.Serializer):
     """
@@ -79,6 +83,10 @@ class CourseInformationSerializerV2(serializers.Serializer):
         course_key = course.id
         mfe_base_url = settings.INSTRUCTOR_MICROFRONTEND_URL
 
+        if not mfe_base_url:
+            log.warning('INSTRUCTOR_MICROFRONTEND_URL is not set.')
+            mfe_base_url = ''
+
         access = {
             'admin': request.user.is_staff,
             'instructor': bool(has_access(request.user, 'instructor', course)),
diff --git a/lms/envs/devstack.py b/lms/envs/devstack.py
index dd7097df71..cca704e065 100644
--- a/lms/envs/devstack.py
+++ b/lms/envs/devstack.py
@@ -398,6 +398,7 @@ COMMUNICATIONS_MICROFRONTEND_URL = 'http://localhost:1984'
 AUTHN_MICROFRONTEND_URL = 'http://localhost:1999'
 AUTHN_MICROFRONTEND_DOMAIN = 'localhost:1999'
 EXAMS_DASHBOARD_MICROFRONTEND_URL = 'http://localhost:2020'
+INSTRUCTOR_MICROFRONTEND_URL = 'http://localhost:2003'
 CATALOG_MICROFRONTEND_URL = 'http://localhost:1998/catalog'
 
 ################### FRONTEND APPLICATION DISCUSSIONS ###################