merge from master at 18.4

1 files changed, 8 insertions, 3 deletions

diff --git a/cloudinit/handlers/__init__.py b/cloudinit/handlers/__init__.py
index c3576c04..0db75af9 100644
--- a/cloudinit/handlers/__init__.py
+++ b/cloudinit/handlers/__init__.py
@@ -41,7 +41,7 @@ PART_HANDLER_FN_TMPL = 'part-handler-%03d'
 # For parts without filenames
 PART_FN_TPL = 'part-%03d'
 
-# Different file beginnings to there content type
+# Different file beginnings to their content type
 INCLUSION_TYPES_MAP = {
     '#include': 'text/x-include-url',
     '#include-once': 'text/x-include-once-url',
@@ -52,6 +52,7 @@ INCLUSION_TYPES_MAP = {
     '#cloud-boothook': 'text/cloud-boothook',
     '#cloud-config-archive': 'text/cloud-config-archive',
     '#cloud-config-jsonp': 'text/cloud-config-jsonp',
+    '## template: jinja': 'text/jinja2',
 }
 
 # Sorted longest first
@@ -69,9 +70,13 @@ class Handler(object):
     def __repr__(self):
         return "%s: [%s]" % (type_utils.obj_name(self), self.list_types())
 
-    @abc.abstractmethod
     def list_types(self):
-        raise NotImplementedError()
+        # Each subclass must define the supported content prefixes it handles.
+        if not hasattr(self, 'prefixes'):
+            raise NotImplementedError('Missing prefixes subclass attribute')
+        else:
+            return [INCLUSION_TYPES_MAP[prefix]
+                    for prefix in getattr(self, 'prefixes')]
 
     @abc.abstractmethod
     def handle_part(self, *args, **kwargs):