Merge "Don't raise if an object's attribute is None in _retrieve_attribute"

ironic/common/exception.py

@@ -1151,11 +1151,6 @@ class TBNComparatorCollectionTypeMismatch(TraitBasedNetworkingException):
     pass
 
 
-class TBNAttributeRetrievalException(TraitBasedNetworkingException):
-    """Specified attribute could not be found."""
-    _msg_fmt = _("Could not retrieve attribute %(attr_name)s from "
-                 "passed object")
-
 class TBNNoTraitsApplicableToNode(TraitBasedNetworkingException):
     """If no traits apply to a node, then nothing can be done."""
     _msg_fmt = _("No Trait Based Networking traits were found which could "

ironic/common/trait_based_networking/base.py

@@ -149,12 +149,7 @@ class Variables(enum.Enum):
 
 def _retrieve_attribute(attribute_name, tbn_obj):
     """Helper method to get an attribute from a TBN related object"""
-    attribute = getattr(tbn_obj, attribute_name, None)
-
-    if attribute is None:
-        raise exc.TBNAttributeRetrievalException(attr_name=attribute_name)
-
-    return attribute
+    return getattr(tbn_obj, attribute_name, '')
 
 
 # Allows special case FilterExpression evaluations where Port does not
@@ -496,9 +491,6 @@ class Network:
     def from_vif_info(cls, vif_info):
         """Helper method to create Networks from vif_info dictionaries"""
         # tags defaults to an empty frozenset (rather than None)
-        # so that filters referencing network.tags don't raise
-        # TBNAttributeRetrievalException just because the vif_attach caller
-        # didn't supply a 'tags' key.
         return cls(vif_info['id'], # vif_info is guaranteed to have 'id'.
                    vif_info.get('name'),
                    frozenset(vif_info.get('tags') or []))

ironic/tests/unit/common/trait_based_networking/test_base.py

@@ -26,7 +26,7 @@ class TraitBasedNetworkingBaseTestCase(base.TestCase):
         )
         self.assertEqual("port.address == 'test'", str(exp))
 
-    def test_filter_object_missing_attribute_raises(self):
+    def test_filter_object_missing_attribute_doesnt_match(self):
         exp = tbn.SingleExpression(
             tbn.Variables.PORT_ADDRESS, tbn.Comparator.EQUALITY, "test"
         )
@@ -34,8 +34,7 @@ class TraitBasedNetworkingBaseTestCase(base.TestCase):
         obj = tbn.Port.from_ironic_port(
             tbn_test_utils.FauxPortLikeObject(address=None))
         net = tbn_test_utils.FauxNetwork()
-        self.assertRaises(exc.TraitBasedNetworkingException, exp.eval,
-                          obj, net)
+        self.assertFalse(exp.eval(obj, net))
 
     def test_filter_comparator_eval_equality(self):
         exp = tbn.SingleExpression(