Fix exception to string in py34

python 3.4 does not have a self.message, so we need to set one up
in our own base class so the conversion to string work.

Change-Id: I5d963125ccb5cc29fa0563313d229046a81ca3d0

oslo_vmware/exceptions.py

@@ -86,6 +86,8 @@ class VMwareDriverException(Exception):
                 # at least get the core message out if something happened
                 message = self.msg_fmt
 
+        if six.PY3:
+            self.message = message
         super(VMwareDriverException, self).__init__(message)
 
     @property

oslo_vmware/tests/test_exceptions.py

@@ -16,7 +16,6 @@
 """
 Unit tests for exceptions module.
 """
-
 from oslo_vmware._i18n import _
 from oslo_vmware import exceptions
 from oslo_vmware.tests import base
@@ -79,6 +78,10 @@ class ExceptionsTest(base.TestCase):
                           exceptions.register_fault_class,
                           'ValueError', ValueError)
 
+    def test_log_exception_to_string(self):
+        self.assertEqual('Insufficient disk space.',
+                         str(exceptions.NoDiskSpaceException()))
+
     def test_get_fault_class(self):
         self.assertEqual(exceptions.AlreadyExistsException,
                          exceptions.get_fault_class("AlreadyExists"))