Add a resource_facade intrinsic function to HOT

Add a native version of the function, rather than continue to rely on
Fn::ResourceFacade from the Heat-flavoured-cfn templates.

Closes-bug: #1299205

Change-Id: Iee118aeaa72d59e4d6a27ed487b99e9aba9779cd

3 files changed, 95 insertions, 2 deletions

diff --git a/heat/engine/cfn/functions.py b/heat/engine/cfn/functions.py
index f21975a95..1bfbace5b 100644
--- a/heat/engine/cfn/functions.py
+++ b/heat/engine/cfn/functions.py
@@ -527,10 +527,10 @@ class ResourceFacade(function.Function):
         if attr == self.METADATA:
             return self.stack.parent_resource.metadata
         elif attr == self.UPDATE_POLICY:
-            up = self.stack.parent_resource.t.get(attr, {})
+            up = self.stack.parent_resource.t.get('UpdatePolicy', {})
             return function.resolve(up)
         elif attr == self.DELETION_POLICY:
-            dp = self.stack.parent_resource.t.get(attr, 'Delete')
+            dp = self.stack.parent_resource.t.get('DeletionPolicy', 'Delete')
             return function.resolve(dp)
 
 
diff --git a/heat/engine/hot/functions.py b/heat/engine/hot/functions.py
index 470413b94..6c6fb87a0 100644
--- a/heat/engine/hot/functions.py
+++ b/heat/engine/hot/functions.py
@@ -203,6 +203,26 @@ class GetFile(function.Function):
         return f
 
 
+class ResourceFacade(cfn_funcs.ResourceFacade):
+    '''
+    A function for obtaining data from the facade resource from within the
+    corresponding provider template.
+
+    Takes the form::
+
+        resource_facade: <attribute_type>
+
+    where the valid attribute types are "metadata", "deletion_policy" and
+    "update_policy".
+    '''
+
+    _RESOURCE_ATTRIBUTES = (
+        METADATA, DELETION_POLICY, UPDATE_POLICY,
+    ) = (
+        'metadata', 'deletion_policy', 'update_policy'
+    )
+
+
 def function_mapping(version_key, version):
     if version_key != 'heat_template_version':
         return {}
@@ -221,6 +241,7 @@ def function_mapping(version_key, version):
             'Fn::Replace': cfn_funcs.Replace,
             'Fn::Base64': cfn_funcs.Base64,
             'Fn::MemberListToMap': cfn_funcs.MemberListToMap,
+            'resource_facade': ResourceFacade,
             'Fn::ResourceFacade': cfn_funcs.ResourceFacade,
             'get_file': GetFile,
         }
diff --git a/heat/tests/test_hot.py b/heat/tests/test_hot.py
index f38c922f8..7946f9e39 100644
--- a/heat/tests/test_hot.py
+++ b/heat/tests/test_hot.py
@@ -512,6 +512,78 @@ class HOTemplateTest(HeatTestCase):
         observed = parsed_tmpl.version
         self.assertEqual(expected, observed)
 
+    def test_resource_facade(self):
+        metadata_snippet = {'resource_facade': 'metadata'}
+        deletion_policy_snippet = {'resource_facade': 'deletion_policy'}
+        update_policy_snippet = {'resource_facade': 'update_policy'}
+
+        class DummyClass(object):
+            pass
+        parent_resource = DummyClass()
+        parent_resource.metadata = {"foo": "bar"}
+        parent_resource.t = {'DeletionPolicy': 'Retain',
+                             'UpdatePolicy': {"blarg": "wibble"}}
+        parent_resource.stack = parser.Stack(utils.dummy_context(),
+                                             'toplevel_stack',
+                                             parser.Template({}))
+        stack = parser.Stack(utils.dummy_context(), 'test_stack',
+                             parser.Template(hot_tpl_empty),
+                             parent_resource=parent_resource)
+        self.assertEqual({"foo": "bar"},
+                         self.resolve(metadata_snippet, stack.t, stack))
+        self.assertEqual('Retain',
+                         self.resolve(deletion_policy_snippet, stack.t, stack))
+        self.assertEqual({"blarg": "wibble"},
+                         self.resolve(update_policy_snippet, stack.t, stack))
+
+    def test_resource_facade_function(self):
+        deletion_policy_snippet = {'resource_facade': 'deletion_policy'}
+
+        class DummyClass(object):
+            pass
+        parent_resource = DummyClass()
+        parent_resource.metadata = {"foo": "bar"}
+        parent_resource.stack = parser.Stack(utils.dummy_context(),
+                                             'toplevel_stack',
+                                             parser.Template({}))
+        parent_snippet = {'DeletionPolicy': {'Fn::Join': ['eta',
+                                                          ['R', 'in']]}}
+        parent_tmpl = parent_resource.stack.t.parse(parent_resource.stack,
+                                                    parent_snippet)
+        parent_resource.t = parent_tmpl
+
+        stack = parser.Stack(utils.dummy_context(), 'test_stack',
+                             parser.Template(hot_tpl_empty),
+                             parent_resource=parent_resource)
+        self.assertEqual('Retain',
+                         self.resolve(deletion_policy_snippet, stack.t, stack))
+
+    def test_resource_facade_invalid_arg(self):
+        snippet = {'resource_facade': 'wibble'}
+        stack = parser.Stack(utils.dummy_context(), 'test_stack',
+                             parser.Template(hot_tpl_empty))
+        error = self.assertRaises(ValueError,
+                                  self.resolve,
+                                  snippet,
+                                  stack.t, stack)
+        self.assertIn(snippet.keys()[0], str(error))
+
+    def test_resource_facade_missing_deletion_policy(self):
+        snippet = {'resource_facade': 'deletion_policy'}
+
+        class DummyClass(object):
+            pass
+        parent_resource = DummyClass()
+        parent_resource.metadata = {"foo": "bar"}
+        parent_resource.t = {}
+        parent_resource.stack = parser.Stack(utils.dummy_context(),
+                                             'toplevel_stack',
+                                             parser.Template({}))
+        stack = parser.Stack(utils.dummy_context(), 'test_stack',
+                             parser.Template(hot_tpl_empty),
+                             parent_resource=parent_resource)
+        self.assertEqual('Delete', self.resolve(snippet, stack.t, stack))
+
 
 class StackTest(test_parser.StackTest):
     """Test stack function when stack was created from HOT template."""