From 5f37259d9c2f9397f4aa9e110eb91331b3d2e478 Mon Sep 17 00:00:00 2001
From: Angus Salkeld <asalkeld@mirantis.com>
Date: Tue, 24 Feb 2015 12:36:28 +1000
Subject: [PATCH] Handle NotFound exception in total_nested()

Change-Id: Ia6044539bd78c7202a6cde84bb9567c8df5b8904
Closes-bug: 1424899
---
 heat/engine/stack.py      |  7 ++++++-
 heat/tests/test_parser.py | 12 +++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/heat/engine/stack.py b/heat/engine/stack.py
index f47aff09f9..5f4dd4406f 100644
--- a/heat/engine/stack.py
+++ b/heat/engine/stack.py
@@ -228,7 +228,12 @@ class Stack(collections.Mapping):
         def total_nested(res):
             get_nested = getattr(res, 'nested', None)
             if callable(get_nested):
-                nested_stack = get_nested()
+                try:
+                    nested_stack = get_nested()
+                except exception.NotFound:
+                    # when an delete is underway, a nested stack can
+                    # disapear at any moment.
+                    return 0
                 if nested_stack is not None:
                     return nested_stack.total_resources()
             return 0
diff --git a/heat/tests/test_parser.py b/heat/tests/test_parser.py
index cfce642b94..f53e089102 100644
--- a/heat/tests/test_parser.py
+++ b/heat/tests/test_parser.py
@@ -1046,7 +1046,7 @@ class StackTest(common.HeatTestCase):
                              status_reason='blarg')
         self.assertEqual(1, stack.total_resources())
 
-    def test_total_resources_nested(self):
+    def test_total_resources_nested_ok(self):
         tpl = {'HeatTemplateFormatVersion': '2012-12-12',
                'Resources':
                {'A': {'Type': 'GenericResourceType'}}}
@@ -1057,6 +1057,16 @@ class StackTest(common.HeatTestCase):
         stack['A'].nested.return_value.total_resources.return_value = 3
         self.assertEqual(4, stack.total_resources())
 
+    def test_total_resources_nested_not_found(self):
+        tpl = {'HeatTemplateFormatVersion': '2012-12-12',
+               'Resources':
+               {'A': {'Type': 'GenericResourceType'}}}
+        stack = parser.Stack(self.ctx, 'test_stack', parser.Template(tpl),
+                             status_reason='blarg')
+
+        stack['A'].nested = mock.Mock(side_effect=exception.NotFound('gone'))
+        self.assertEqual(1, stack.total_resources())
+
     def test_iter_resources(self):
         tpl = {'HeatTemplateFormatVersion': '2012-12-12',
                'Resources':