Raise NotFound() when group member does not exist

Raise NotFound() exception with proper message when fetching
atrribitutes for a member, that is not in the nested stack.

Change-Id: I8969893781439ef5e87ea9f815d7f22e23be3e78
Closes-Bug: #1723315

heat/common/grouputils.py

@@ -14,6 +14,7 @@
 import six
 
 from heat.common import exception
+from heat.common.i18n import _
 
 
 def get_size(group, include_failed=False):
@@ -69,7 +70,7 @@ def get_member_names(group):
     return [r.name for r in get_members(group)]
 
 
-def get_resource(stack, resource_name, use_indices, key):
+def get_resource(stack, resource_name, use_indices, key=None):
     nested_stack = stack.nested()
     if not nested_stack:
         return None
@@ -79,18 +80,20 @@ def get_resource(stack, resource_name, use_indices, key):
         else:
             return nested_stack[resource_name]
     except (IndexError, KeyError):
-        raise exception.InvalidTemplateAttribute(resource=stack.name,
-                                                 key=key)
+        raise exception.NotFound(_("Member '%(mem)s' not found "
+                                   "in group resource '%(grp)s'.")
+                                 % {'mem': resource_name,
+                                    'grp': stack.name})
 
 
 def get_rsrc_attr(stack, key, use_indices, resource_name, *attr_path):
-    resource = get_resource(stack, resource_name, use_indices, key)
+    resource = get_resource(stack, resource_name, use_indices)
     if resource:
         return resource.FnGetAtt(*attr_path)
 
 
 def get_rsrc_id(stack, key, use_indices, resource_name):
-    resource = get_resource(stack, resource_name, use_indices, key)
+    resource = get_resource(stack, resource_name, use_indices)
     if resource:
         return resource.FnGetRefId()
 

heat/tests/autoscaling/test_heat_scaling_group.py

@@ -462,7 +462,7 @@ class HeatScalingGroupAttrTest(common.HeatTestCase):
         mock_members.return_value = members
         self.assertEqual(output[0], self.group.FnGetAtt('resource.0', 'Bar'))
         self.assertEqual(output[1], self.group.FnGetAtt('resource.1.Bar'))
-        self.assertRaises(exception.InvalidTemplateAttribute,
+        self.assertRaises(exception.NotFound,
                           self.group.FnGetAtt, 'resource.2')
 
 

heat/tests/openstack/heat/test_resource_group.py

@@ -865,8 +865,10 @@ class ResourceGroupAttrTest(common.HeatTestCase):
         resg = self._create_dummy_stack()
         self.assertEqual("ID-0", resg.FnGetAtt('resource.0'))
         self.assertEqual("ID-1", resg.FnGetAtt('resource.1'))
-        self.assertRaises(exception.InvalidTemplateAttribute, resg.FnGetAtt,
-                          'resource.2')
+        ex = self.assertRaises(exception.NotFound, resg.FnGetAtt,
+                               'resource.2')
+        self.assertIn("Member '2' not found in group resource 'group1'.",
+                      six.text_type(ex))
 
     @mock.patch.object(grouputils, 'get_rsrc_id')
     def test_get_attribute(self, mock_get_rsrc_id):