From f256b61dd222f64fbcdea98c98060352ffab517f Mon Sep 17 00:00:00 2001
From: Zane Bitter <zbitter@redhat.com>
Date: Thu, 29 Jun 2017 09:07:02 -0400
Subject: [PATCH] Refactor out a new Resource.referenced_attrs() method

Calculating all of the attributes of a resource that are referenced in the
template was previously done inside the node_data() method, but this is
useful for the resource to be able to access for other reasons so refactor
it into a separate method.

Change-Id: I8ec943652e6f93a2352f2ea5e6ac46e0088e5458
Related-Bug: #1660831
Partially-Implements: blueprint stack-definition
---
 heat/engine/resource.py                     | 32 ++++++++++++++-----
 heat/tests/test_stack_collect_attributes.py | 35 +++++++++++++++++++++
 2 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/heat/engine/resource.py b/heat/engine/resource.py
index 7668175d30..f2105e330f 100644
--- a/heat/engine/resource.py
+++ b/heat/engine/resource.py
@@ -918,6 +918,30 @@ class Resource(status.ResourceStatus):
             self._rsrc_prop_data = None
             self.attributes.reset_resolved_values()
 
+    def referenced_attrs(self, in_resources=True, in_outputs=True):
+        """Return the set of all attributes referenced in the template.
+
+        This enables the resource to calculate which of its attributes will
+        be used. By default, attributes referenced in either other resources
+        or outputs will be included. Either can be excluded by setting the
+        `in_resources` or `in_outputs` parameters to False.
+        """
+        def get_dep_attrs(source_dict):
+            return set(self.stack.get_dep_attrs(six.itervalues(source_dict),
+                                                self.name))
+
+        refd_attrs = set()
+        if in_resources:
+            refd_attrs |= get_dep_attrs(self.stack.resources)
+        if in_outputs:
+            refd_attrs |= get_dep_attrs(self.stack.outputs)
+
+        if attributes.ALL_ATTRIBUTES in refd_attrs:
+            refd_attrs.remove(attributes.ALL_ATTRIBUTES)
+            refd_attrs |= (set(self.attributes) - {self.SHOW})
+
+        return refd_attrs
+
     def node_data(self):
         def get_attrs(attrs):
             for attr in attrs:
@@ -927,13 +951,7 @@ class Resource(status.ResourceStatus):
                 except exception.InvalidTemplateAttribute as ita:
                     LOG.info('%s', ita)
 
-        dep_attrs = set(self.stack.get_dep_attrs(
-            six.itervalues(self.stack.resources),
-            self.name))
-        if attributes.ALL_ATTRIBUTES in dep_attrs:
-            dep_attrs.remove(attributes.ALL_ATTRIBUTES)
-            dep_attrs |= (set(self.attributes) - {self.SHOW})
-
+        dep_attrs = self.referenced_attrs(in_outputs=False)
         return node_data.NodeData(self.id, self.name, self.uuid,
                                   self.get_reference_id(),
                                   dict(get_attrs(dep_attrs)),
diff --git a/heat/tests/test_stack_collect_attributes.py b/heat/tests/test_stack_collect_attributes.py
index 71c3c93f15..596bf12d45 100644
--- a/heat/tests/test_stack_collect_attributes.py
+++ b/heat/tests/test_stack_collect_attributes.py
@@ -232,3 +232,38 @@ class DepAttrsTest(common.HeatTestCase):
                              self.stack.get_dep_attrs(
                                  resources,
                                  res.name))
+
+
+class ReferencedAttrsTest(common.HeatTestCase):
+    def setUp(self):
+        super(ReferencedAttrsTest, self).setUp()
+        parsed_tmpl = template_format.parse(tmpl6)
+        self.stack = stack.Stack(utils.dummy_context(), 'test_stack',
+                                 template.Template(parsed_tmpl))
+        self.resA = self.stack['AResource']
+        self.resB = self.stack['BResource']
+
+    def test_referenced_attrs_resources(self):
+        self.assertEqual(self.resA.referenced_attrs(in_resources=True,
+                                                    in_outputs=False),
+                         {('list', 1), ('nested_dict', 'dict', 'b')})
+        self.assertEqual(self.resB.referenced_attrs(in_resources=True,
+                                                    in_outputs=False),
+                         set())
+
+    def test_referenced_attrs_outputs(self):
+        self.assertEqual(self.resA.referenced_attrs(in_resources=False,
+                                                    in_outputs=True),
+                         {('flat_dict', 'key2'), ('nested_dict', 'string')})
+        self.assertEqual(self.resB.referenced_attrs(in_resources=False,
+                                                    in_outputs=True),
+                         {'attr_B3'})
+
+    def test_referenced_attrs_both(self):
+        self.assertEqual(self.resA.referenced_attrs(in_resources=True,
+                                                    in_outputs=True),
+                         {('list', 1), ('nested_dict', 'dict', 'b'),
+                          ('flat_dict', 'key2'), ('nested_dict', 'string')})
+        self.assertEqual(self.resB.referenced_attrs(in_resources=True,
+                                                    in_outputs=True),
+                         {'attr_B3'})