From 45fde101979d9d3f446cd937e5cc4c47539cc5bc Mon Sep 17 00:00:00 2001
From: Thomas Herve <therve@redhat.com>
Date: Thu, 20 Apr 2017 15:11:08 +0200
Subject: [PATCH] Copy template version when update fails

When an update fails, we may have copy some chunk of resources or
parameters to the new template. If the version was updated and the new
resources require the version, this can lead to a state where the stack
is in an usable state. This synchronizes the version when a failure
happens.

Change-Id: I2faf8f3541fc800ea61c417e5575f4a56a83665b
Closes-Bug: #1620696
---
 heat/engine/stack.py                          |  5 ++
 .../functional/test_create_update.py          | 48 +++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/heat/engine/stack.py b/heat/engine/stack.py
index a07cea7e5a..3b2ddbe1ce 100644
--- a/heat/engine/stack.py
+++ b/heat/engine/stack.py
@@ -1579,9 +1579,14 @@ class Stack(collections.Mapping):
                 # and new stack resources, we should have user params of both.
                 existing_params.load(newstack.t.env.user_env_as_dict())
                 self.t.env = existing_params
+                # Update the template version, in case new things were used
+                self.t.t[newstack.t.version[0]] = max(
+                    newstack.t.version[1], self.t.version[1])
                 self.t.merge_snippets(newstack.t)
                 self.t.store(self.context)
                 backup_stack.t.env = existing_params
+                backup_stack.t.t[newstack.t.version[0]] = max(
+                    newstack.t.version[1], self.t.version[1])
                 backup_stack.t.merge_snippets(newstack.t)
                 backup_stack.t.store(self.context)
             self.store()
diff --git a/heat_integrationtests/functional/test_create_update.py b/heat_integrationtests/functional/test_create_update.py
index 771404ab5d..ae81463d30 100644
--- a/heat_integrationtests/functional/test_create_update.py
+++ b/heat_integrationtests/functional/test_create_update.py
@@ -625,3 +625,51 @@ resources:
         self.assertEqual({'test1': 'OS::Heat::TestResource',
                           'test2': 'My::TestResource'},
                          self.list_resources(stack_identifier))
+
+    def test_stack_update_with_new_version(self):
+        """Update handles new template version in failure.
+
+        If a stack update fails while changing the template version, update is
+        able to handle the new version fine.
+        """
+        stack_identifier = self.stack_create(
+            template=test_template_one_resource)
+
+        # Update with a new function and make the update fails
+        template = _change_rsrc_properties(test_template_two_resource,
+                                           ['test1'], {'fail': True})
+
+        template['heat_template_version'] = '2015-10-15'
+        template['resources']['test2']['properties']['value'] = {
+            'list_join': [',', ['a'], ['b']]}
+        self.update_stack(stack_identifier,
+                          template=template,
+                          expected_status='UPDATE_FAILED')
+
+        template = _change_rsrc_properties(template,
+                                           ['test2'], {'value': 'Test2'})
+        self.update_stack(stack_identifier,
+                          template=template,
+                          expected_status='UPDATE_FAILED')
+        self._stack_delete(stack_identifier)
+
+    def test_stack_update_with_old_version(self):
+        """Update handles old template version in failure.
+
+        If a stack update fails while changing the template version, update is
+        able to handle the old version fine.
+        """
+        template = _change_rsrc_properties(
+            test_template_one_resource,
+            ['test1'], {'value': {'list_join': [',', ['a'], ['b']]}})
+        template['heat_template_version'] = '2015-10-15'
+        stack_identifier = self.stack_create(
+            template=template)
+
+        # Update with a new function and make the update fails
+        template = _change_rsrc_properties(test_template_one_resource,
+                                           ['test1'], {'fail': True})
+        self.update_stack(stack_identifier,
+                          template=template,
+                          expected_status='UPDATE_FAILED')
+        self._stack_delete(stack_identifier)