Merge "Change template loading to use stevedore extensions"

heat/engine/cfn/template.py

@@ -147,10 +147,3 @@ class CfnTemplate(template.Template):
 
         self.t.setdefault(self.RESOURCES, {})
         self.t[self.RESOURCES][name] = cfn_tmpl
-
-
-def template_mapping():
-    return {
-        ('HeatTemplateFormatVersion', '2012-12-12'): CfnTemplate,
-        ('AWSTemplateFormatVersion', '2010-09-09'): CfnTemplate,
-    }

heat/engine/hot/template.py

@@ -223,9 +223,3 @@ class HOTemplate(template.Template):
 
         self.t.setdefault(self.RESOURCES, {})
         self.t[self.RESOURCES][name] = definition.render_hot()
-
-
-def template_mapping():
-    return {
-        ('heat_template_version', '2013-05-23'): HOTemplate,
-    }

heat/engine/template.py

@@ -15,6 +15,7 @@ import abc
 import collections
 import copy
 import functools
+from stevedore import extension
 
 from heat.common import exception
 from heat.db import api as db_api
@@ -76,8 +77,12 @@ def get_template_class(plugin_mgr, template_data):
     global _template_classes
 
     if _template_classes is None:
-        tmpl_mapping = plugin_manager.PluginMapping('template')
-        _template_classes = dict(tmpl_mapping.load_all(plugin_mgr))
+        mgr = extension.ExtensionManager(
+            namespace='heat.templates',
+            invoke_on_load=False,
+            verify_requirements=True)
+        _template_classes = dict((tuple(name.split('.')), mgr[name].plugin)
+                                 for name in mgr.names())
 
     available_versions = _template_classes.keys()
     version = get_version(template_data, available_versions)

setup.cfg

@@ -45,6 +45,12 @@ heat.constraints =
     nova.keypair = heat.engine.resources.nova_keypair:KeypairConstraint
 
 
+heat.templates =
+   heat_template_version.2013-05-23 = heat.engine.hot.template:HOTemplate
+   HeatTemplateFormatVersion.2012-12-12 = heat.engine.cfn.template:CfnTemplate
+   AWSTemplateFormatVersion.2010-09-09 = heat.engine.cfn.template:CfnTemplate
+
+
 [global]
 setup-hooks =
     pbr.hooks.setup_hook