Make TestRPC inherit from the base nova TestCase

By not inheriting from the base nova test case, we
lose things like timeouts.

This makes the TestRPC test class inherit from the
base test case and still avoid using the RPCFixture.

Change-Id: Id65e15a57175bbdd9c84851b1b6716e6a1f2cfb8
Related-Bug: #1685333

nova/test.py

@@ -209,6 +209,9 @@ class TestCase(testtools.TestCase):
     USES_DB_SELF = False
     REQUIRES_LOCKING = False
 
+    # Setting to True makes the test use the RPCFixture.
+    STUB_RPC = True
+
     # The number of non-cell0 cells to create. This is only used in the
     # base class when USES_DB is True.
     NUMBER_OF_CELLS = 1
@@ -250,7 +253,9 @@ class TestCase(testtools.TestCase):
                                 group='oslo_concurrency')
 
         self.useFixture(conf_fixture.ConfFixture(CONF))
-        self.useFixture(nova_fixtures.RPCFixture('nova.test'))
+
+        if self.STUB_RPC:
+            self.useFixture(nova_fixtures.RPCFixture('nova.test'))
 
         # we cannot set this in the ConfFixture as oslo only registers the
         # notification opts at the first instantiation of a Notifier that

nova/tests/unit/test_rpc.py

@@ -18,7 +18,6 @@ import mock
 import oslo_messaging as messaging
 from oslo_messaging.rpc import dispatcher
 from oslo_serialization import jsonutils
-import testtools
 
 from nova import context
 from nova import rpc
@@ -45,9 +44,11 @@ class RPCResetFixture(fixtures.Fixture):
         rpc.CONF = self.conf
 
 
-# We can't import nova.test.TestCase because that sets up an RPCFixture
-# that pretty much nullifies all of this testing
-class TestRPC(testtools.TestCase):
+class TestRPC(test.NoDBTestCase):
+
+    # We're testing the rpc code so we can't use the RPCFixture.
+    STUB_RPC = False
+
     def setUp(self):
         super(TestRPC, self).setUp()
         self.useFixture(RPCResetFixture())