Get custom_tag templates using system.filestore so that they work in multicourse

common/lib/xmodule/xmodule/template_module.py

 from xmodule.x_module import XModule
 from xmodule.raw_module import RawDescriptor
 from lxml import etree
+from mako.template import Template
 
 
 class CustomTagModule(XModule):
@@ -30,9 +31,10 @@ class CustomTagModule(XModule):
     def __init__(self, system, location, definition, instance_state=None, shared_state=None, **kwargs):
         XModule.__init__(self, system, location, definition, instance_state, shared_state, **kwargs)
         xmltree = etree.fromstring(self.definition['data'])
-        filename = xmltree.find('impl').text
+        template_name = xmltree.find('impl').text
         params = dict(xmltree.items())
-        self.html = self.system.render_template(filename, params, namespace='custom_tags')
+        with self.system.filestore.open('custom_tags/{name}'.format(name=template_name)) as template:
+            self.html = Template(template.read()).render(**params)
 
     def get_html(self):
         return self.html

lms/envs/common.py

@@ -69,21 +69,15 @@ sys.path.append(COMMON_ROOT / 'lib')
 # templates
 MAKO_MODULE_DIR = tempfile.mkdtemp('mako')
 MAKO_TEMPLATES = {}
-MAKO_TEMPLATES['course'] = [DATA_DIR]
-MAKO_TEMPLATES['sections'] = [DATA_DIR / 'sections']
-MAKO_TEMPLATES['custom_tags'] = [DATA_DIR / 'custom_tags']
 MAKO_TEMPLATES['main'] = [PROJECT_ROOT / 'templates',
                           COMMON_ROOT / 'templates',
                           COMMON_ROOT / 'lib' / 'capa' / 'templates',
-                          COMMON_ROOT / 'djangoapps' / 'pipeline_mako' / 'templates',
-                          DATA_DIR / 'info',
-                          DATA_DIR / 'problems']
+                          COMMON_ROOT / 'djangoapps' / 'pipeline_mako' / 'templates']
 
 # This is where Django Template lookup is defined. There are a few of these 
 # still left lying around.
 TEMPLATE_DIRS = (
     PROJECT_ROOT / "templates",
-    DATA_DIR / "problems",
 )
 
 TEMPLATE_CONTEXT_PROCESSORS = (