Allow get_attr: [res_name] format to get all attribute

Don't check None attribute name if want to get all
attributes of resource, and this only works in template
'2015-10-15' or higher version.

Change-Id: I6699bfc8bc8096e5dc313d01b3a829694c105fea
Closes-Bug: #1505560

heat/engine/cfn/functions.py

@@ -176,9 +176,19 @@ class GetAtt(function.Function):
         return itertools.chain(super(GetAtt, self).dependencies(path),
                                [self._resource(path)])
 
+    def _allow_without_attribute_name(self):
+        return False
+
     def validate(self):
         super(GetAtt, self).validate()
         res = self._resource()
+
+        if self._allow_without_attribute_name():
+            # if allow without attribute_name, then don't check
+            # when attribute_name is None
+            if self._attribute is None:
+                return
+
         attr = function.resolve(self._attribute)
         from heat.engine import resource
         if (type(res).FnGetAtt == resource.Resource.FnGetAtt and

heat/engine/hot/functions.py

@@ -218,6 +218,9 @@ class GetAttAllAttributes(GetAtt):
         else:
             return super(GetAttAllAttributes, self).result()
 
+    def _allow_without_attribute_name(self):
+        return True
+
 
 class Replace(cfn_funcs.Replace):
     """A function for performing string substitutions.

heat/tests/test_function.py

@@ -280,3 +280,10 @@ class ValidateGetAttTest(common.HeatTestCase):
         func = functions.GetAtt(self.stack, 'Fn::GetAtt',
                                 [self.rsrc.name, 'Foo'])
         self.assertIsNone(func.validate())
+
+    def test_get_attr_without_attribute_name(self):
+        ex = self.assertRaises(ValueError, functions.GetAtt,
+                               self.stack, 'Fn::GetAtt', [self.rsrc.name])
+        self.assertEqual('Arguments to "Fn::GetAtt" must be '
+                         'of the form [resource_name, attribute]',
+                         six.text_type(ex))

heat/tests/test_hot.py

@@ -2096,3 +2096,18 @@ class TestGetAttAllAttributes(common.HeatTestCase):
             else:
                 self.assertEqual(self.expected,
                                  self.resolve(self.snippet, tmpl, stack))
+
+    def test_stack_validate_outputs_get_all_attribute(self):
+        hot_liberty_tpl = template_format.parse('''
+heat_template_version: 2015-10-15
+resources:
+  resource1:
+    type: GenericResourceType
+outputs:
+  all_attr:
+    value: {get_attr: [resource1]}
+''')
+
+        stack = parser.Stack(utils.dummy_context(), 'test_outputs_get_all',
+                             template.Template(hot_liberty_tpl))
+        stack.validate()