Allow deletion_policy to be lowercase in HOT

This is more consistent with the rest of the HOT language.

Change-Id: I445e986b067a1311efc23a5d350bd81976253a3f

doc/source/template_guide/hot_spec.rst

@@ -645,8 +645,11 @@ update_policy
 
 deletion_policy
     Deletion policy for the resource. The allowed deletion policies are
-    ``Delete``, ``Retain``, and ``Snapshot``.
+    ``Delete``, ``Retain``, and ``Snapshot``. Beginning with
-    This attribute is optional; the default policy is ``Delete``.
+    ``heat_template_version`` ``2016-10-14``, the lowercase equivalents
+    ``delete``, ``retain``, and ``snapshot`` are also allowed.
+    This attribute is optional; the default policy is to delete the physical
+    resource when deleting a resource from the stack.
 
 Depending on the type of resource, the resource block might include more
 resource specific data.

heat/engine/hot/template.py

@@ -404,6 +404,17 @@ class HOTemplate20160408(HOTemplate20151015):
 
 
 class HOTemplate20161014(HOTemplate20160408):
+    deletion_policies = {
+        'Delete': rsrc_defn.ResourceDefinition.DELETE,
+        'Retain': rsrc_defn.ResourceDefinition.RETAIN,
+        'Snapshot': rsrc_defn.ResourceDefinition.SNAPSHOT,
+
+        # aliases added in 2016-10-14
+        'delete': rsrc_defn.ResourceDefinition.DELETE,
+        'retain': rsrc_defn.ResourceDefinition.RETAIN,
+        'snapshot': rsrc_defn.ResourceDefinition.SNAPSHOT,
+    }
+
     functions = {
         'get_attr': hot_funcs.GetAttAllAttributes,
         'get_file': hot_funcs.GetFile,

heat/tests/test_hot.py

@@ -513,6 +513,54 @@ class HOTemplateTest(common.HeatTestCase):
                                  {'get_attr': ['rg', 'name']}]}
         self.assertEqual('', self.resolve(snippet, tmpl, stack))
 
+    def test_deletion_policy_titlecase(self):
+        hot_tpl = template_format.parse('''
+        heat_template_version: 2016-10-14
+        resources:
+          del:
+            type: OS::Heat::None
+            deletion_policy: Delete
+          ret:
+            type: OS::Heat::None
+            deletion_policy: Retain
+          snap:
+            type: OS::Heat::None
+            deletion_policy: Snapshot
+        ''')
+
+        rsrc_defns = template.Template(hot_tpl).resource_definitions(None)
+
+        self.assertEqual(rsrc_defn.ResourceDefinition.DELETE,
+                         rsrc_defns['del'].deletion_policy())
+        self.assertEqual(rsrc_defn.ResourceDefinition.RETAIN,
+                         rsrc_defns['ret'].deletion_policy())
+        self.assertEqual(rsrc_defn.ResourceDefinition.SNAPSHOT,
+                         rsrc_defns['snap'].deletion_policy())
+
+    def test_deletion_policy(self):
+        hot_tpl = template_format.parse('''
+        heat_template_version: 2016-10-14
+        resources:
+          del:
+            type: OS::Heat::None
+            deletion_policy: delete
+          ret:
+            type: OS::Heat::None
+            deletion_policy: retain
+          snap:
+            type: OS::Heat::None
+            deletion_policy: snapshot
+        ''')
+
+        rsrc_defns = template.Template(hot_tpl).resource_definitions(None)
+
+        self.assertEqual(rsrc_defn.ResourceDefinition.DELETE,
+                         rsrc_defns['del'].deletion_policy())
+        self.assertEqual(rsrc_defn.ResourceDefinition.RETAIN,
+                         rsrc_defns['ret'].deletion_policy())
+        self.assertEqual(rsrc_defn.ResourceDefinition.SNAPSHOT,
+                         rsrc_defns['snap'].deletion_policy())
+
     def test_str_replace(self):
         """Test str_replace function."""