prevent leakage of FLAGS changes across tests

nova/flags.py

@@ -90,6 +90,12 @@ class FlagValues(gflags.FlagValues):
         self.ClearDirty()
         return args
 
+    def Reset(self):
+        gflags.FlagValues.Reset(self)
+        self.__dict__['__dirty'] = []
+        self.__dict__['__was_already_parsed'] = False
+        self.__dict__['__stored_argv'] = []
+
     def SetDirty(self, name):
         """Mark a flag as dirty so that accessing it will case a reparse."""
         self.__dict__['__dirty'].append(name)

nova/test.py

@@ -22,9 +22,9 @@ Allows overriding of flags for use of fakes,
 and some black magic for inline callbacks.
 """
 
+import datetime
 import sys
 import time
-import datetime
 
 import mox
 import stubout
@@ -80,30 +80,33 @@ class TrialTestCase(unittest.TestCase):
         self.flag_overrides = {}
         self.injected = []
         self._monkeyPatchAttach()
+        self._original_flags = FLAGS.FlagValuesDict()
 
     def tearDown(self): # pylint: disable-msg=C0103
         """Runs after each test method to finalize/tear down test environment"""
-        self.reset_flags()
-        self.mox.UnsetStubs()
-        self.stubs.UnsetAll()
-        self.stubs.SmartUnsetAll()
-        self.mox.VerifyAll()
-        # NOTE(vish): Clean up any ips associated during the test.
-        ctxt = context.get_admin_context()
-        db.fixed_ip_disassociate_all_by_timeout(ctxt, FLAGS.host, self.start)
-        db.network_disassociate_all(ctxt)
-        rpc.Consumer.attach_to_twisted = self.originalAttach
-        for x in self.injected:
-            try:
-                x.stop()
-            except AssertionError:
-                pass
+        try:
+            self.mox.UnsetStubs()
+            self.stubs.UnsetAll()
+            self.stubs.SmartUnsetAll()
+            self.mox.VerifyAll()
+            # NOTE(vish): Clean up any ips associated during the test.
+            ctxt = context.get_admin_context()
+            db.fixed_ip_disassociate_all_by_timeout(ctxt, FLAGS.host, self.start)
+            db.network_disassociate_all(ctxt)
+            rpc.Consumer.attach_to_twisted = self.originalAttach
+            for x in self.injected:
+                try:
+                    x.stop()
+                except AssertionError:
+                    pass
 
-        if FLAGS.fake_rabbit:
-            fakerabbit.reset_all()
-        db.security_group_destroy_all(ctxt)
+            if FLAGS.fake_rabbit:
+                fakerabbit.reset_all()
 
-        super(TrialTestCase, self).tearDown()
+            db.security_group_destroy_all(ctxt)
+            super(TrialTestCase, self).tearDown()
+        finally:
+            self.reset_flags()
 
     def flags(self, **kw):
         """Override flag variables for a test"""
@@ -117,7 +120,8 @@ class TrialTestCase(unittest.TestCase):
 
     def reset_flags(self):
         """Resets all flag variables for the test.  Runs after each test"""
-        for k, v in self.flag_overrides.iteritems():
+        FLAGS.Reset()
+        for k, v in self._original_flags.iteritems():
             setattr(FLAGS, k, v)
 
     def run(self, result=None):
@@ -171,12 +175,6 @@ class BaseTestCase(TrialTestCase):
         self._done_waiting = False
         self._timed_out = False
 
-    def tearDown(self):# pylint: disable-msg=C0103
-        """Runs after each test method to finalize/tear down test environment"""
-        super(BaseTestCase, self).tearDown()
-        if FLAGS.fake_rabbit:
-            fakerabbit.reset_all()
-
     def _wait_for_test(self, timeout=60):
         """ Push the ioloop along to wait for our test to complete. """
         self._waiting = self.ioloop.add_timeout(time.time() + timeout,

nova/tests/flags_unittest.py

@@ -20,6 +20,8 @@ from nova import exception
 from nova import flags
 from nova import test
 
+FLAGS = flags.FLAGS
+flags.DEFINE_string('flags_unittest', 'foo', 'for testing purposes only')
 
 class FlagsTestCase(test.TrialTestCase):
     def setUp(self):
@@ -85,3 +87,13 @@ class FlagsTestCase(test.TrialTestCase):
 
         self.assert_('runtime_answer' in self.global_FLAGS)
         self.assertEqual(self.global_FLAGS.runtime_answer, 60)
+
+    def test_flag_leak_left(self):
+        self.assertEqual(FLAGS.flags_unittest, 'foo')
+        FLAGS.flags_unittest = 'bar'
+        self.assertEqual(FLAGS.flags_unittest, 'bar')
+
+    def test_flag_leak_right(self):
+        self.assertEqual(FLAGS.flags_unittest, 'foo')
+        FLAGS.flags_unittest = 'bar'
+        self.assertEqual(FLAGS.flags_unittest, 'bar')