Ensure lease polling raises proper exception

This patch adds the ability to properly translate and raise
VimExceptions when polling the state of the lease.

Change-Id: Ie22808471d4c72e26607e817167e0e2283630b5a

3 files changed, 57 insertions, 11 deletions

diff --git a/oslo_vmware/api.py b/oslo_vmware/api.py
index 81c44ef..f30fd35 100644
--- a/oslo_vmware/api.py
+++ b/oslo_vmware/api.py
@@ -446,16 +446,7 @@ class VMwareAPISession(object):
                           get_completed_task())
                 raise loopingcall.LoopingCallDone(task_info)
             else:
-                error_msg = six.text_type(task_info.error.localizedMessage)
-                error = task_info.error
-                name = error.fault.__class__.__name__
-                fault_class = exceptions.get_fault_class(name)
-                if fault_class:
-                    task_ex = fault_class(error_msg)
-                else:
-                    task_ex = exceptions.VimFaultException([name],
-                                                           error_msg)
-                raise task_ex
+                raise exceptions.translate_fault(task_info.error)
 
     def wait_for_lease_ready(self, lease):
         """Waits for the given lease to be ready.
@@ -506,7 +497,7 @@ class VMwareAPISession(object):
                               "%(error_msg)s.") % {'lease': lease,
                                                    'error_msg': error_msg}
                 LOG.error(excep_msg)
-                raise exceptions.VimException(excep_msg)
+                raise exceptions.translate_fault(error_msg, excep_msg)
             else:
                 # unknown state
                 excep_msg = _("Unknown state: %(state)s for lease: "
diff --git a/oslo_vmware/exceptions.py b/oslo_vmware/exceptions.py
index 4018a82..df6d676 100644
--- a/oslo_vmware/exceptions.py
+++ b/oslo_vmware/exceptions.py
@@ -296,6 +296,32 @@ def get_fault_class(name):
     return fault_class
 
 
+def translate_fault(localized_method_fault, excep_msg=None):
+    """Produce proper VimException subclass object,
+
+    The exception is based on a vmodl.LocalizedMethodFault.
+
+    :param excep_msg: Message to set to the exception. Defaults to
+                      localizedMessage of the fault.
+    """
+    try:
+        if not excep_msg:
+            excep_msg = six.text_type(localized_method_fault.localizedMessage)
+        name = localized_method_fault.fault.__class__.__name__
+        fault_class = get_fault_class(name)
+        if fault_class:
+            ex = fault_class(excep_msg)
+        else:
+            ex = VimFaultException([name], excep_msg)
+    except Exception as e:
+        LOG.debug("Unexpected exception thrown (%s) while translating"
+                  " fault (%s) with message: %s.",
+                  e, localized_method_fault, excep_msg)
+        ex = VimException(message=excep_msg, cause=e)
+
+    return ex
+
+
 def register_fault_class(name, exception):
     fault_class = _fault_classes_registry.get(name)
     if not issubclass(exception, VimException):
diff --git a/oslo_vmware/tests/test_exceptions.py b/oslo_vmware/tests/test_exceptions.py
index 2ef24a7..d70756b 100644
--- a/oslo_vmware/tests/test_exceptions.py
+++ b/oslo_vmware/tests/test_exceptions.py
@@ -16,6 +16,8 @@
 """
 Unit tests for exceptions module.
 """
+import mock
+
 from oslo_vmware._i18n import _
 from oslo_vmware import exceptions
 from oslo_vmware.tests import base
@@ -119,3 +121,30 @@ class ExceptionsTest(base.TestCase):
                          exceptions.get_fault_class("ManagedObjectNotFound"))
         # Test unknown fault.
         self.assertIsNone(exceptions.get_fault_class("NotAFile"))
+
+    def test_translate_fault(self):
+
+        def fake_task(fault_class_name, error_msg=None):
+            task_info = mock.Mock()
+            task_info.localizedMessage = error_msg
+            if fault_class_name:
+                error_fault = mock.Mock()
+                error_fault.__class__.__name__ = fault_class_name
+                task_info.fault = error_fault
+            return task_info
+
+        error_msg = "OUCH"
+        task = fake_task(exceptions.FILE_LOCKED, error_msg)
+        actual = exceptions.translate_fault(task)
+
+        expected = exceptions.FileLockedException(error_msg)
+        self.assertEqual(expected.__class__, actual.__class__)
+        self.assertEqual(expected.message, actual.message)
+
+        error_msg = "Oopsie"
+        task = fake_task(None, error_msg)
+        actual = exceptions.translate_fault(task)
+        expected = exceptions.VimFaultException(['Mock'], message=error_msg)
+        self.assertEqual(expected.__class__, actual.__class__)
+        self.assertEqual(expected.message, actual.message)
+        self.assertEqual(expected.fault_list, actual.fault_list)