Add the course root to the bulk email template context so that templates can…

Add the course root to the bulk email template context so that templates can customize the full course URL with a custom hostname.

lms/djangoapps/bulk_email/admin.py

@@ -36,6 +36,7 @@ two curly braces on each side), to indicate where the email text is to be insert
 Other tags that may be used (surrounded by one curly brace on each side):
 {platform_name}        : the name of the platform
 {course_title}         : the name of the course
+{course_root}          : the URL path to the root of the course
 {course_url}           : the course's full URL
 {email}                : the user's email address
 {account_settings_url} : URL at which users can change account preferences

lms/djangoapps/bulk_email/tasks.py

@@ -100,13 +100,15 @@ def _get_course_email_context(course):
     course_id = course.id.to_deprecated_string()
     course_title = course.display_name
     course_end_date = get_default_time_display(course.end)
+    course_root = reverse('course_root', kwargs={'course_id': course_id})
     course_url = '{}{}'.format(
         settings.LMS_ROOT_URL,
-        reverse('course_root', kwargs={'course_id': course_id})
+        course_root
     )
     image_url = u'{}{}'.format(settings.LMS_ROOT_URL, course_image_url(course))
     email_context = {
         'course_title': course_title,
+        'course_root': course_root,
         'course_url': course_url,
         'course_image_url': image_url,
         'course_end_date': course_end_date,

lms/djangoapps/bulk_email/tests/test_tasks.py

@@ -33,6 +33,7 @@ from django.core.management import call_command
 from xmodule.modulestore.tests.factories import CourseFactory
 
 from bulk_email.models import CourseEmail, Optout, SEND_TO_MYSELF, SEND_TO_STAFF, SEND_TO_LEARNERS
+from bulk_email.tasks import _get_course_email_context
 
 from instructor_task.tasks import send_bulk_course_email
 from instructor_task.subtasks import update_subtask_status, SubtaskStatus
@@ -434,3 +435,14 @@ class TestBulkEmailInstructorTask(InstructorTaskCourseTestCase):
         with patch('bulk_email.tasks.get_connection', autospec=True) as get_conn:
             get_conn.return_value.send_messages.side_effect = cycle([None])
             self._test_run_with_task(send_bulk_course_email, 'emailed', num_emails, num_emails)
+
+    def test_get_course_email_context_has_correct_keys(self):
+        result = _get_course_email_context(self.course)
+        self.assertIn('course_title', result)
+        self.assertIn('course_root', result)
+        self.assertIn('course_url', result)
+        self.assertIn('course_image_url', result)
+        self.assertIn('course_end_date', result)
+        self.assertIn('account_settings_url', result)
+        self.assertIn('email_settings_url', result)
+        self.assertIn('platform_name', result)