Merge "Make template validation uniform"

doc/source/template_guide/hot_spec.rst

@@ -80,8 +80,9 @@ parameters
 
 resources
     This section contains the declaration of the single resources of the
-    template. This section is mandatory and at least one resource must be
+    template. This section with at least one resource should be defined in any
-    defined in any HOT template.
+    HOT template, or the template would not really do anything when being
+    instantiated.
 
 outputs
     This section allows for specifying output parameters available to users once

heat/engine/service.py

@@ -600,7 +600,7 @@ class EngineService(service.Service):
 
         # validate overall template
         try:
-            tmpl.validate(allow_empty=False)
+            tmpl.validate()
         except Exception as ex:
             return {'Error': six.text_type(ex)}
 

heat/engine/template.py

@@ -18,7 +18,9 @@ import functools
 from heat.common import exception
 from heat.db import api as db_api
 from heat.engine import plugin_manager
+from heat.openstack.common import log as logging
 
+logger = logging.getLogger(__name__)
 
 __all__ = ['Template']
 
@@ -172,7 +174,7 @@ class Template(collections.Mapping):
     def parse(self, stack, snippet):
         return parse(self.functions(), stack, snippet)
 
-    def validate(self, allow_empty=True):
+    def validate(self):
         '''Validate the template.
 
         Validates the top-level sections of the template as well as syntax
@@ -180,7 +182,6 @@ class Template(collections.Mapping):
         code parts that are responsible for working with the respective
         sections (e.g. parameters are check by parameters schema class).
 
-        :param allow_empty: whether to allow an empty resources section
         '''
 
         # check top-level sections
@@ -190,11 +191,10 @@ class Template(collections.Mapping):
 
         # check resources
         tmpl_resources = self[self.RESOURCES]
-
+        if not tmpl_resources:
-        if not allow_empty and not tmpl_resources:
+            logger.warn(_('Template does not contain any resources, so '
-            message = _('The template is invalid. A Resources section with at '
+                          'the template would not really do anything when '
-                        'least one resource must be defined.')
+                          'being instantiated.'))
-            raise exception.StackValidationFailed(message=message)
 
         for res in tmpl_resources.values():
             try:

heat/tests/test_validate.py

@@ -1076,9 +1076,8 @@ class validateTest(HeatTestCase):
 
         engine = service.EngineService('a', 't')
         res = dict(engine.validate_template(None, hot_tpl, {}))
-        self.assertEqual({'Error': 'The template is invalid. '
+        expected = {'Description': 'No description', 'Parameters': {}}
-                          'A Resources section with at least one resource '
+        self.assertEqual(expected, res)
-                          'must be defined.'}, res)
 
     def test_validate_template_with_invalid_resource_type(self):
         hot_tpl = template_format.parse('''