From: Zane Bitter <zbitter@redhat.com>
Date: Thu, 22 Aug 2013 11:01:21 +0000 (+0200)
Subject: Pass the previous stack to StackUpdate
X-Git-Tag: 2014.1~174^2
X-Git-Url: https://review.fuel-infra.org/gitweb?a=commitdiff_plain;h=f2e9b31a965e3ef0168da1f9dc65afb2d8e24810;p=openstack-build%2Fheat-build.git

Pass the previous stack to StackUpdate

This starts out like the existing stack, but is not stored in the database
or updated as the stack update proceeds. This allows the StackUpdate object
to store any information that might be relevant to a future rollback.

Change-Id: I94f0dd69b5e7818f811c8c0d50566a79b81acba7
---

diff --git a/heat/engine/parser.py b/heat/engine/parser.py
index 56a60b6b..70a343f3 100644
--- a/heat/engine/parser.py
+++ b/heat/engine/parser.py
@@ -383,16 +383,17 @@ class Stack(object):
                                'State invalid for %s' % action)
                 return
 
-        current_env = self.env
-        self.env = newstack.env
-        self.parameters = newstack.parameters
-
         self.state_set(self.UPDATE, self.IN_PROGRESS,
                        'Stack %s started' % action)
 
+        oldstack = Stack(self.context, self.name, self.t, self.env)
         try:
-            update_task = update.StackUpdate(self, newstack)
+            update_task = update.StackUpdate(self, newstack, oldstack)
             updater = scheduler.TaskRunner(update_task)
+
+            self.env = newstack.env
+            self.parameters = newstack.parameters
+
             try:
                 updater(timeout=self.timeout_secs())
             finally:
@@ -416,8 +417,6 @@ class Stack(object):
                 # If rollback is enabled, we do another update, with the
                 # existing template, so we roll back to the original state
                 if not self.disable_rollback:
-                    oldstack = Stack(self.context, self.name, self.t,
-                                     current_env)
                     self.update(oldstack, action=self.ROLLBACK)
                     return
 
diff --git a/heat/engine/update.py b/heat/engine/update.py
index 85cf62fb..5e44a507 100644
--- a/heat/engine/update.py
+++ b/heat/engine/update.py
@@ -26,10 +26,11 @@ class StackUpdate(object):
     A Task to perform the update of an existing stack to a new template.
     """
 
-    def __init__(self, existing_stack, new_stack):
+    def __init__(self, existing_stack, new_stack, previous_stack):
         """Initialise with the existing stack and the new stack."""
         self.existing_stack = existing_stack
         self.new_stack = new_stack
+        self.previous_stack = previous_stack
 
         self.existing_snippets = dict((r.name, r.parsed_template())
                                       for r in self.existing_stack)