Pass hostname to LTI XModule

Necessary for RFC compliance with oauthlib

common/lib/capa/capa/tests/__init__.py

@@ -36,6 +36,7 @@ def test_system():
         user=Mock(),
         filestore=fs.osfs.OSFS(os.path.join(TEST_DIR, "test_files")),
         debug=True,
+        hostname="edx.org",
         xqueue={'interface': xqueue_interface, 'construct_callback': calledback_url, 'default_queuename': 'testqueue', 'waittime': 10},
         node_path=os.environ.get("NODE_PATH", "/usr/local/lib/node_modules"),
         anonymous_student_id='student',

common/lib/xmodule/xmodule/lti_module.py

@@ -6,7 +6,7 @@ http://www.imsglobal.org/LTI/v1p1p1/ltiIMGv1p1p1.html
 """
 
 import logging
-import oauthlib
+import oauthlib.oauth1
 import urllib
 
 from xmodule.editing_module import MetadataOnlyEditingDescriptor
@@ -212,8 +212,11 @@ class LTIModule(LTIFields, XModule):
         # appending custom parameter for signing
         body.update(custom_parameters)
 
-        # This is needed for body encoding:
-        headers = {'Content-Type': 'application/x-www-form-urlencoded'}
+        headers = {
+            'Host': self.system.HOSTNAME,
+            # This is needed for body encoding:
+            'Content-Type': 'application/x-www-form-urlencoded',
+        }
 
         __, headers, __ = client.sign(
             unicode(self.launch_url),

common/lib/xmodule/xmodule/tests/__init__.py

@@ -62,6 +62,7 @@ def get_test_system(course_id=''):
         user=Mock(is_staff=False),
         filestore=Mock(),
         debug=True,
+        hostname="edx.org",
         xqueue={'interface': None, 'callback_url': '/', 'default_queuename': 'testqueue', 'waittime': 10, 'construct_callback' : Mock(side_effect="/")},
         node_path=os.environ.get("NODE_PATH", "/usr/local/lib/node_modules"),
         xblock_field_data=lambda descriptor: descriptor._field_data,

common/lib/xmodule/xmodule/x_module.py

@@ -833,7 +833,7 @@ class ModuleSystem(Runtime):
     def __init__(
             self, ajax_url, track_function, get_module, render_template,
             replace_urls, xblock_field_data, user=None, filestore=None,
-            debug=False, xqueue=None, publish=None, node_path="",
+            debug=False, hostname="", xqueue=None, publish=None, node_path="",
             anonymous_student_id='', course_id=None,
             open_ended_grading_interface=None, s3_interface=None,
             cache=None, can_execute_unsafe_code=None, replace_course_urls=None,
@@ -897,6 +897,7 @@ class ModuleSystem(Runtime):
         self.get_module = get_module
         self.render_template = render_template
         self.DEBUG = self.debug = debug
+        self.HOSTNAME = self.hostname = hostname
         self.seed = user.id if user is not None else 0
         self.replace_urls = replace_urls
         self.node_path = node_path