From db6a62c737f4abbca18779ce26277dd7558dfc57 Mon Sep 17 00:00:00 2001
From: Richard Lee <rblee88@gmail.com>
Date: Tue, 21 Jan 2014 17:43:33 -0800
Subject: [PATCH] Add preview for LoadBalancer

Override ``child_template`` and ``child_params``, since LoadBalancer is
really a StackResource.

Implements: blueprint preview-stack (partial)
Change-Id: Ie31cd1059fe95c2bdca5d6afed566b7e00d8002d
---
 heat/engine/resources/loadbalancer.py | 35 ++++++++++++++++--------
 heat/tests/test_loadbalancer.py       | 39 +++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/heat/engine/resources/loadbalancer.py b/heat/engine/resources/loadbalancer.py
index 33580db80c..bd705f37e5 100644
--- a/heat/engine/resources/loadbalancer.py
+++ b/heat/engine/resources/loadbalancer.py
@@ -432,25 +432,38 @@ class LoadBalancer(stack_resource.StackResource):
             contents = lb_template_default
         return template_format.parse(contents)
 
-    def handle_create(self):
+    def child_params(self):
+        params = {}
+
+        # If the owning stack defines KeyName, we use that key for the nested
+        # template, otherwise use no key
+        if 'KeyName' in self.stack.parameters:
+            params['KeyName'] = self.stack.parameters['KeyName']
+
+        return params
+
+    def child_template(self):
         templ = self.get_parsed_template()
 
+        # If the owning stack defines KeyName, we use that key for the nested
+        # template, otherwise use no key
+        if 'KeyName' not in self.stack.parameters:
+            del templ['Resources']['LB_instance']['Properties']['KeyName']
+            del templ['Parameters']['KeyName']
+
+        return templ
+
+    def handle_create(self):
+        templ = self.child_template()
+        params = self.child_params()
+
         if self.properties[self.INSTANCES]:
             md = templ['Resources']['LB_instance']['Metadata']
             files = md['AWS::CloudFormation::Init']['config']['files']
             cfg = self._haproxy_config(templ, self.properties[self.INSTANCES])
             files['/etc/haproxy/haproxy.cfg']['content'] = cfg
 
-        # If the owning stack defines KeyName, we use that key for the nested
-        # template, otherwise use no key
-        try:
-            param = {'KeyName': self.stack.parameters['KeyName']}
-        except KeyError:
-            del templ['Resources']['LB_instance']['Properties']['KeyName']
-            del templ['Parameters']['KeyName']
-            param = {}
-
-        return self.create_with_template(templ, param)
+        return self.create_with_template(templ, params)
 
     def handle_update(self, json_snippet, tmpl_diff, prop_diff):
         '''
diff --git a/heat/tests/test_loadbalancer.py b/heat/tests/test_loadbalancer.py
index 2248b3d30a..0e37e7fd04 100644
--- a/heat/tests/test_loadbalancer.py
+++ b/heat/tests/test_loadbalancer.py
@@ -13,6 +13,7 @@
 #    under the License.
 
 
+import mock
 import mox
 import re
 
@@ -241,3 +242,41 @@ class LoadBalancerTest(HeatTestCase):
                                t['Resources']['LoadBalancer'],
                                s)
         self.assertRaises(exception.StackValidationFailed, rsrc.validate)
+
+    def setup_loadbalancer(self, include_keyname=True):
+        template = template_format.parse(lb_template)
+        if not include_keyname:
+            del template['Parameters']['KeyName']
+        stack = utils.parse_stack(template)
+
+        resource_name = 'LoadBalancer'
+        lb_json = template['Resources'][resource_name]
+        return lb.LoadBalancer(resource_name, lb_json, stack)
+
+    def test_child_params_without_key_name(self):
+        rsrc = self.setup_loadbalancer(False)
+        self.assertEqual({}, rsrc.child_params())
+
+    def test_child_params_with_key_name(self):
+        rsrc = self.setup_loadbalancer()
+        params = rsrc.child_params()
+        self.assertEqual('test', params['KeyName'])
+
+    def test_child_template_without_key_name(self):
+        rsrc = self.setup_loadbalancer(False)
+        parsed_template = {
+            'Resources': {'LB_instance': {'Properties': {'KeyName': 'foo'}}},
+            'Parameters': {'KeyName': 'foo'}
+        }
+        rsrc.get_parsed_template = mock.Mock(return_value=parsed_template)
+
+        tmpl = rsrc.child_template()
+        self.assertNotIn('KeyName', tmpl['Parameters'])
+        self.assertNotIn('KeyName',
+                         tmpl['Resources']['LB_instance']['Properties'])
+
+    def test_child_template_with_key_name(self):
+        rsrc = self.setup_loadbalancer()
+        rsrc.get_parsed_template = mock.Mock(return_value='foo')
+
+        self.assertEqual('foo', rsrc.child_template())