Prevent parallel test port clashes for zmq.

The scheme of incrementing port numbers did not work so well for
parallel test runs.

Part of blueprint grizzly-testtools.

Change-Id: I100e79ae79e4409691145dc721139d1a86839199

2 files changed, 14 insertions, 6 deletions

diff --git a/tests/unit/rpc/test_zmq.py b/tests/unit/rpc/test_zmq.py
index 2f0c20d..2aac2b3 100644
--- a/tests/unit/rpc/test_zmq.py
+++ b/tests/unit/rpc/test_zmq.py
@@ -23,6 +23,7 @@ eventlet.monkey_patch()
 
 import logging
 import os
+import socket
 
 import fixtures
 
@@ -44,17 +45,23 @@ LOG = logging.getLogger(__name__)
 FLAGS = cfg.CONF
 
 
+def get_unused_port():
+    """
+    Returns an unused port on localhost.
+    """
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s.bind(('localhost', 0))
+    addr, port = s.getsockname()
+    s.close()
+    return port
+
+
 class _RpcZmqBaseTestCase(common.BaseRpcTestCase):
-    # TESTCNT needs to be a class var as each run
-    # by subclasses must have a unique identifier
-    TESTCNT = 0
     rpc = impl_zmq
 
     def setUp(self, topic='test', topic_nested='nested'):
         if not impl_zmq:
             self.skipTest("ZeroMQ library required")
-        _RpcZmqBaseTestCase.TESTCNT += 1
-        testcnt = _RpcZmqBaseTestCase.TESTCNT
 
         self.reactor = None
         self.rpc = impl_zmq
@@ -74,7 +81,7 @@ class _RpcZmqBaseTestCase(common.BaseRpcTestCase):
             #                  between tearDown() and setUp()
             # TODO(mordred): replace this with testresources once we're on
             #                testr
-            self.config(rpc_zmq_port=9500 + testcnt)
+            self.config(rpc_zmq_port=get_unused_port())
             internal_ipc_dir = self.useFixture(fixtures.TempDir()).path
             self.config(rpc_zmq_ipc_dir=internal_ipc_dir)
 
diff --git a/tests/utils.py b/tests/utils.py
index 3c749f6..f9854ca 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -35,6 +35,7 @@ class BaseTestCase(testtools.TestCase):
         self.stubs = self.useFixture(moxstubout.MoxStubout()).stubs
         self.addCleanup(CONF.reset)
         self.useFixture(fixtures.FakeLogger('openstack.common'))
+        self.useFixture(fixtures.Timeout(30, True))
 
     def config(self, **kw):
         """