Adds a waffle switch which gates access to the CourseEnrollmentAdmin views

common/djangoapps/student/admin.py

@@ -1,5 +1,6 @@
 """ Django admin pages for student app """
 from config_models.admin import ConfigurationModelAdmin
+import waffle
 from django import forms
 from django.contrib import admin
 from django.contrib.admin.sites import NotRegistered
@@ -165,13 +166,7 @@ class CourseEnrollmentForm(forms.ModelForm):
         fields = '__all__'
 
 
-# Page disabled because it makes DB quries that impact performance enough to
-# cause a site outage. It may be re-enabled when it is updated to make more
-# efficent DB queries
-# https://openedx.atlassian.net/browse/OPS-2943
-# Learner ticket to add functionality to /support
-# https://openedx.atlassian.net/browse/LEARNER-4744
-#@admin.register(CourseEnrollment)
+@admin.register(CourseEnrollment)
 class CourseEnrollmentAdmin(admin.ModelAdmin):
     """ Admin interface for the CourseEnrollment model. """
     list_display = ('id', 'course_id', 'mode', 'user', 'is_active',)
@@ -183,6 +178,43 @@ class CourseEnrollmentAdmin(admin.ModelAdmin):
     def queryset(self, request):
         return super(CourseEnrollmentAdmin, self).queryset(request).select_related('user')
 
+    def has_permission(self, request, method):
+        """
+        Returns True if the given method is allowed.
+
+        Access to these admin views is restricted because it makes DB quries that impact performance enough to cause a
+        site outage, cf https://openedx.atlassian.net/browse/OPS-2943
+
+        Enable these views using the waffle switch: `student.coursenrollment.admin`
+        """
+        if waffle.switch_is_active('student.coursenrollment.admin'):
+            return getattr(super(CourseEnrollmentAdmin, self), method)(request)
+        return False
+
+    def has_add_permission(self, request):
+        """
+        Returns True if CourseEnrollment objects can be added via the admin view.
+        """
+        return self.has_permission(request, 'has_add_permission')
+
+    def has_change_permission(self, request, obj=None):
+        """
+        Returns True if CourseEnrollment objects can be modified via the admin view.
+        """
+        return self.has_permission(request, 'has_change_permission')
+
+    def has_delete_permission(self, request, obj=None):
+        """
+        Returns True if CourseEnrollment objects can be deleted via the admin view.
+        """
+        return self.has_permission(request, 'has_delete_permission')
+
+    def has_module_permission(self, request):
+        """
+        Returns True if links to the CourseEnrollment admin view can be displayed.
+        """
+        return self.has_permission(request, 'has_module_permission')
+
 
 class UserProfileInline(admin.StackedInline):
     """ Inline admin interface for UserProfile model. """

common/djangoapps/student/tests/test_admin_views.py

@@ -1,6 +1,8 @@
 """
 Tests student admin.py
 """
+import ddt
+from waffle.testutils import override_switch
 from django.contrib.admin.sites import AdminSite
 from django.contrib.auth.models import User
 from django.urls import reverse
@@ -8,7 +10,7 @@ from django.test import TestCase
 from mock import Mock
 
 from student.admin import UserAdmin
-from student.tests.factories import UserFactory
+from student.tests.factories import CourseEnrollmentFactory, UserFactory
 from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 
@@ -186,3 +188,49 @@ class AdminUserPageTest(TestCase):
         request = Mock()
         user = Mock()
         self.assertIn('username', self.admin.get_readonly_fields(request, user))
+
+
+@ddt.ddt
+class CourseEnrollmentAdminTest(SharedModuleStoreTestCase):
+    """
+    Unit tests for the CourseEnrollmentAdmin view.
+    """
+    ADMIN_URLS = (
+        ('get', reverse('admin:student_courseenrollment_add')),
+        ('get', reverse('admin:student_courseenrollment_changelist')),
+        ('get', reverse('admin:student_courseenrollment_change', args=(1,))),
+        ('get', reverse('admin:student_courseenrollment_delete', args=(1,))),
+        ('post', reverse('admin:student_courseenrollment_add')),
+        ('post', reverse('admin:student_courseenrollment_changelist')),
+        ('post', reverse('admin:student_courseenrollment_change', args=(1,))),
+        ('post', reverse('admin:student_courseenrollment_delete', args=(1,))),
+    )
+
+    def setUp(self):
+        super(CourseEnrollmentAdminTest, self).setUp()
+        self.user = UserFactory.create(is_staff=True, is_superuser=True)
+        self.client.login(username=self.user.username, password='test')
+        CourseEnrollmentFactory(
+            user=self.user,
+            course_id=CourseFactory().id,  # pylint: disable=no-member
+        )
+
+    @ddt.data(*ADMIN_URLS)
+    @ddt.unpack
+    def test_view_disabled(self, method, url):
+        """
+        All CourseEnrollmentAdmin views are disabled by default.
+        """
+        response = getattr(self.client, method)(url)
+        self.assertEqual(response.status_code, 403)
+
+    @override_switch('student.coursenrollment.admin', active=True)
+    @ddt.data(*ADMIN_URLS)
+    @ddt.unpack
+    def test_view_enabled(self, method, url):
+        """
+        Ensure CourseEnrollmentAdmin views can be enabled with the waffle flag.
+        """
+        self.client.login(username=self.user.username, password='test')
+        response = getattr(self.client, method)(url)
+        self.assertEqual(response.status_code, 200)