Use fixtures library for nova test fixtures.

Moving the test-case setup and teardown code into managed fixtures
so that we can better interact with them when we start running things
in parallel.

Part of blueprint grizzly-testtools

Change-Id: I406be0a88b14c0dba2d22b4957e26a53442bbae3

10 files changed, 199 insertions, 181 deletions

diff --git a/bin/nova-dhcpbridge b/bin/nova-dhcpbridge
index 8ff2fac49..0e3d89e65 100755
--- a/bin/nova-dhcpbridge
+++ b/bin/nova-dhcpbridge
@@ -103,7 +103,7 @@ def main():
     logging.setup("nova")
 
     if int(os.environ.get('TESTING', '0')):
-        from nova.tests import fake_flags
+        from nova.tests import conf_fixture
 
     action = argv[1]
     if action in ['add', 'del', 'old']:
diff --git a/nova/test.py b/nova/test.py
index 1e9945bbc..9de766b22 100644
--- a/nova/test.py
+++ b/nova/test.py
@@ -29,12 +29,11 @@ import sys
 import uuid
 
 import eventlet
-from fixtures import EnvironmentVariable
+import fixtures
 import mox
 import stubout
 import testtools
 
-from nova import config
 from nova import context
 from nova import db
 from nova.db import migration
@@ -45,7 +44,7 @@ from nova.openstack.common import log as logging
 from nova.openstack.common import timeutils
 from nova import service
 from nova import tests
-from nova.tests import fake_flags
+from nova.tests import conf_fixture
 from nova.tests import policy_fixture
 from nova.tests import utils
 
@@ -71,63 +70,112 @@ LOG = logging.getLogger(__name__)
 
 eventlet.monkey_patch(os=False)
 
-_DB = None
+_DB_CACHE = None
 
 
-def reset_db():
-    if CONF.sql_connection == "sqlite://":
-        engine = get_engine()
-        engine.dispose()
-        conn = engine.connect()
-        if _DB:
-            conn.connection.executescript(_DB)
+class Database(fixtures.Fixture):
+
+    def __init__(self):
+        self.engine = get_engine()
+        self.engine.dispose()
+        conn = self.engine.connect()
+        if CONF.sql_connection == "sqlite://":
+            if migration.db_version() > migration.INIT_VERSION:
+                return
+        else:
+            testdb = os.path.join(CONF.state_path, CONF.sqlite_db)
+            if os.path.exists(testdb):
+                return
+        migration.db_sync()
+        ctxt = context.get_admin_context()
+        network = network_manager.VlanManager()
+        bridge_interface = CONF.flat_interface or CONF.vlan_interface
+        network.create_networks(ctxt,
+                                label='test',
+                                cidr=CONF.fixed_range,
+                                multi_host=CONF.multi_host,
+                                num_networks=CONF.num_networks,
+                                network_size=CONF.network_size,
+                                cidr_v6=CONF.fixed_range_v6,
+                                gateway=CONF.gateway,
+                                gateway_v6=CONF.gateway_v6,
+                                bridge=CONF.flat_network_bridge,
+                                bridge_interface=bridge_interface,
+                                vpn_start=CONF.vpn_start,
+                                vlan_start=CONF.vlan_start,
+                                dns1=CONF.flat_network_dns)
+        for net in db.network_get_all(ctxt):
+            network.set_network_host(ctxt, net)
+
+        if CONF.sql_connection == "sqlite://":
+            conn = self.engine.connect()
+            self._DB = "".join(line for line in conn.connection.iterdump())
+            self.engine.dispose()
         else:
-            setup()
-    else:
-        shutil.copyfile(os.path.join(CONF.state_path, CONF.sqlite_clean_db),
-                        os.path.join(CONF.state_path, CONF.sqlite_db))
-
-
-def setup():
-
-    fake_flags.set_defaults(CONF)
-
-    if CONF.sql_connection == "sqlite://":
-        if migration.db_version() > migration.INIT_VERSION:
-            return
-    else:
-        testdb = os.path.join(CONF.state_path, CONF.sqlite_db)
-        if os.path.exists(testdb):
-            return
-    migration.db_sync()
-    ctxt = context.get_admin_context()
-    network = network_manager.VlanManager()
-    bridge_interface = CONF.flat_interface or CONF.vlan_interface
-    network.create_networks(ctxt,
-                            label='test',
-                            cidr=CONF.fixed_range,
-                            multi_host=CONF.multi_host,
-                            num_networks=CONF.num_networks,
-                            network_size=CONF.network_size,
-                            cidr_v6=CONF.fixed_range_v6,
-                            gateway=CONF.gateway,
-                            gateway_v6=CONF.gateway_v6,
-                            bridge=CONF.flat_network_bridge,
-                            bridge_interface=bridge_interface,
-                            vpn_start=CONF.vpn_start,
-                            vlan_start=CONF.vlan_start,
-                            dns1=CONF.flat_network_dns)
-    for net in db.network_get_all(ctxt):
-        network.set_network_host(ctxt, net)
-
-    if CONF.sql_connection == "sqlite://":
-        global _DB
-        engine = get_engine()
-        conn = engine.connect()
-        _DB = "".join(line for line in conn.connection.iterdump())
-    else:
-        cleandb = os.path.join(CONF.state_path, CONF.sqlite_clean_db)
-        shutil.copyfile(testdb, cleandb)
+            cleandb = os.path.join(CONF.state_path, CONF.sqlite_clean_db)
+            shutil.copyfile(testdb, cleandb)
+
+    def setUp(self):
+        super(Database, self).setUp()
+
+        if CONF.sql_connection == "sqlite://":
+            conn = self.engine.connect()
+            conn.connection.executescript(self._DB)
+            self.addCleanup(self.engine.dispose)
+        else:
+            shutil.copyfile(os.path.join(CONF.state_path,
+                                         CONF.sqlite_clean_db),
+                            os.path.join(CONF.state_path,
+                                         CONF.sqlite_db))
+
+
+class ReplaceModule(fixtures.Fixture):
+    """Replace a module with a fake module."""
+
+    def __init__(self, name, new_value):
+        self.name = name
+        self.new_value = new_value
+
+    def _restore(self, old_value):
+        sys.modules[self.name] = old_value
+
+    def setUp(self):
+        super(ReplaceModule, self).setUp()
+        old_value = sys.modules.get(self.name)
+        sys.modules[self.name] = self.new_value
+        self.addCleanup(self._restore, old_value)
+
+
+class ServiceFixture(fixtures.Fixture):
+    """Run a service as a test fixture."""
+
+    def __init__(self, name, host=None, **kwargs):
+        name = name
+        host = host and host or uuid.uuid4().hex
+        kwargs.setdefault('host', host)
+        kwargs.setdefault('binary', 'nova-%s' % name)
+        self.kwargs = kwargs
+
+    def setUp(self):
+        super(ServiceFixture, self).setUp()
+        self.service = service.Service.create(**self.kwargs)
+        self.service.start()
+        self.addCleanup(self.service.kill)
+
+
+class MoxStubout(fixtures.Fixture):
+    """Deal with code around mox and stubout as a fixture."""
+
+    def setUp(self):
+        super(MoxStubout, self).setUp()
+        # emulate some of the mox stuff, we can't use the metaclass
+        # because it screws with our generators
+        self.mox = mox.Mox()
+        self.stubs = stubout.StubOutForTesting()
+        self.addCleanup(self.mox.UnsetStubs)
+        self.addCleanup(self.stubs.UnsetAll)
+        self.addCleanup(self.stubs.SmartUnsetAll)
+        self.addCleanup(self.mox.VerifyAll)
 
 
 class TestingException(Exception):
@@ -141,70 +189,27 @@ class TestCase(testtools.TestCase):
         """Run before each test method to initialize test environment."""
         super(TestCase, self).setUp()
 
-        fake_flags.set_defaults(CONF)
-        config.parse_args([], default_config_files=[])
+        self.log_fixture = self.useFixture(fixtures.FakeLogger('nova'))
+        self.useFixture(conf_fixture.ConfFixture(CONF))
 
-        # NOTE(vish): We need a better method for creating fixtures for tests
-        #             now that we have some required db setup for the system
-        #             to work properly.
-        self.start = timeutils.utcnow()
-        reset_db()
+        global _DB_CACHE
+        if not _DB_CACHE:
+            _DB_CACHE = Database()
+        self.useFixture(_DB_CACHE)
 
-        # emulate some of the mox stuff, we can't use the metaclass
-        # because it screws with our generators
-        self.mox = mox.Mox()
-        self.stubs = stubout.StubOutForTesting()
-        self.injected = []
-        self._services = []
-        self._modules = {}
-        self.useFixture(EnvironmentVariable('http_proxy'))
+        mox_fixture = self.useFixture(MoxStubout())
+        self.mox = mox_fixture.mox
+        self.stubs = mox_fixture.stubs
+        self.addCleanup(self._clear_attrs)
+        self.useFixture(fixtures.EnvironmentVariable('http_proxy'))
         self.policy = self.useFixture(policy_fixture.PolicyFixture())
 
-    def tearDown(self):
-        """Runs after each test method to tear down test environment."""
-        try:
-            utils.cleanup_dns_managers()
-            self.mox.UnsetStubs()
-            self.stubs.UnsetAll()
-            self.stubs.SmartUnsetAll()
-            self.mox.VerifyAll()
-            super(TestCase, self).tearDown()
-        finally:
-            # Reset any overridden flags
-            CONF.reset()
-
-            # Unstub modules
-            for name, mod in self._modules.iteritems():
-                if mod is not None:
-                    sys.modules[name] = mod
-                else:
-                    sys.modules.pop(name)
-            self._modules = {}
-
-            # Stop any timers
-            for x in self.injected:
-                try:
-                    x.stop()
-                except AssertionError:
-                    pass
-
-            # Kill any services
-            for x in self._services:
-                try:
-                    x.kill()
-                except Exception:
-                    pass
-
-            # Delete attributes that don't start with _ so they don't pin
-            # memory around unnecessarily for the duration of the test
-            # suite
-            for key in [k for k in self.__dict__.keys() if k[0] != '_']:
-                del self.__dict__[key]
-
-    def stub_module(self, name, mod):
-        if name not in self._modules:
-            self._modules[name] = sys.modules.get(name)
-        sys.modules[name] = mod
+    def _clear_attrs(self):
+        # Delete attributes that don't start with _ so they don't pin
+        # memory around unnecessarily for the duration of the test
+        # suite
+        for key in [k for k in self.__dict__.keys() if k[0] != '_']:
+            del self.__dict__[key]
 
     def flags(self, **kw):
         """Override flag variables for a test."""
@@ -213,10 +218,5 @@ class TestCase(testtools.TestCase):
             CONF.set_override(k, v, group)
 
     def start_service(self, name, host=None, **kwargs):
-        host = host and host or uuid.uuid4().hex
-        kwargs.setdefault('host', host)
-        kwargs.setdefault('binary', 'nova-%s' % name)
-        svc = service.Service.create(**kwargs)
-        svc.start()
-        self._services.append(svc)
-        return svc
+        svc = self.useFixture(ServiceFixture(name, host, **kwargs))
+        return svc.service
diff --git a/nova/tests/compute/test_rpcapi.py b/nova/tests/compute/test_rpcapi.py
index 54d8d47c7..437daaa14 100644
--- a/nova/tests/compute/test_rpcapi.py
+++ b/nova/tests/compute/test_rpcapi.py
@@ -33,11 +33,11 @@ CONF.import_opt('compute_topic', 'nova.config')
 class ComputeRpcAPITestCase(test.TestCase):
 
     def setUp(self):
+        super(ComputeRpcAPITestCase, self).setUp()
         self.context = context.get_admin_context()
         inst = db.instance_create(self.context, {'host': 'fake_host',
                                                  'instance_type_id': 1})
         self.fake_instance = jsonutils.to_primitive(inst)
-        super(ComputeRpcAPITestCase, self).setUp()
 
     def test_serialized_instance_has_name(self):
         self.assertTrue('name' in self.fake_instance)
diff --git a/nova/tests/conf_fixture.py b/nova/tests/conf_fixture.py
new file mode 100644
index 000000000..c0466447d
--- /dev/null
+++ b/nova/tests/conf_fixture.py
@@ -0,0 +1,66 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import fixtures
+
+from nova import config
+from nova.openstack.common import cfg
+
+CONF = cfg.CONF
+CONF.import_opt('state_path', 'nova.config')
+CONF.import_opt('scheduler_driver', 'nova.scheduler.manager')
+CONF.import_opt('fake_network', 'nova.network.manager')
+CONF.import_opt('network_size', 'nova.network.manager')
+CONF.import_opt('num_networks', 'nova.network.manager')
+CONF.import_opt('policy_file', 'nova.policy')
+CONF.import_opt('compute_driver', 'nova.virt.driver')
+
+
+class ConfFixture(fixtures.Fixture):
+    """Fixture to manage global conf settings."""
+
+    def __init__(self, conf):
+        self.conf = conf
+
+    def setUp(self):
+        super(ConfFixture, self).setUp()
+
+        self.conf.set_default('api_paste_config',
+                              '$state_path/etc/nova/api-paste.ini')
+        self.conf.set_default('compute_driver', 'nova.virt.fake.FakeDriver')
+        self.conf.set_default('fake_network', True)
+        self.conf.set_default('fake_rabbit', True)
+        self.conf.set_default('flat_network_bridge', 'br100')
+        self.conf.set_default('floating_ip_dns_manager',
+                              'nova.tests.utils.dns_manager')
+        self.conf.set_default('instance_dns_manager',
+                              'nova.tests.utils.dns_manager')
+        self.conf.set_default('lock_path', None)
+        self.conf.set_default('network_size', 8)
+        self.conf.set_default('num_networks', 2)
+        self.conf.set_default('rpc_backend',
+                              'nova.openstack.common.rpc.impl_fake')
+        self.conf.set_default('rpc_cast_timeout', 5)
+        self.conf.set_default('rpc_response_timeout', 5)
+        self.conf.set_default('sql_connection', "sqlite://")
+        self.conf.set_default('sqlite_synchronous', False)
+        self.conf.set_default('use_ipv6', True)
+        self.conf.set_default('verbose', True)
+        self.conf.set_default('vlan_interface', 'eth0')
+        config.parse_args([], default_config_files=[])
+        self.addCleanup(self.conf.reset)
diff --git a/nova/tests/fake_flags.py b/nova/tests/fake_flags.py
deleted file mode 100644
index 83ec33cab..000000000
--- a/nova/tests/fake_flags.py
+++ /dev/null
@@ -1,49 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-
-# Copyright 2010 United States Government as represented by the
-# Administrator of the National Aeronautics and Space Administration.
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-from nova.openstack.common import cfg
-
-CONF = cfg.CONF
-CONF.import_opt('state_path', 'nova.config')
-CONF.import_opt('scheduler_driver', 'nova.scheduler.manager')
-CONF.import_opt('fake_network', 'nova.network.manager')
-CONF.import_opt('network_size', 'nova.network.manager')
-CONF.import_opt('num_networks', 'nova.network.manager')
-CONF.import_opt('policy_file', 'nova.policy')
-CONF.import_opt('compute_driver', 'nova.virt.driver')
-
-
-def set_defaults(conf):
-    conf.set_default('api_paste_config', '$state_path/etc/nova/api-paste.ini')
-    conf.set_default('compute_driver', 'nova.virt.fake.FakeDriver')
-    conf.set_default('fake_network', True)
-    conf.set_default('fake_rabbit', True)
-    conf.set_default('flat_network_bridge', 'br100')
-    conf.set_default('network_size', 8)
-    conf.set_default('num_networks', 2)
-    conf.set_default('vlan_interface', 'eth0')
-    conf.set_default('rpc_backend', 'nova.openstack.common.rpc.impl_fake')
-    conf.set_default('sql_connection', "sqlite://")
-    conf.set_default('sqlite_synchronous', False)
-    conf.set_default('use_ipv6', True)
-    conf.set_default('verbose', True)
-    conf.set_default('rpc_response_timeout', 5)
-    conf.set_default('rpc_cast_timeout', 5)
-    conf.set_default('lock_path', None)
-    conf.set_default('floating_ip_dns_manager', 'nova.tests.utils.dns_manager')
-    conf.set_default('instance_dns_manager', 'nova.tests.utils.dns_manager')
diff --git a/nova/tests/integrated/integrated_helpers.py b/nova/tests/integrated/integrated_helpers.py
index 7c316aaa8..1f6a278cf 100644
--- a/nova/tests/integrated/integrated_helpers.py
+++ b/nova/tests/integrated/integrated_helpers.py
@@ -67,7 +67,7 @@ class _IntegratedTestBase(test.TestCase):
         self.flags(**f)
         self.flags(verbose=True)
 
-        self.stub_module('crypto', fake_crypto)
+        self.useFixture(test.ReplaceModule('crypto', fake_crypto))
         nova.tests.image.fake.stub_out_image_service(self.stubs)
         self.flags(scheduler_driver='nova.scheduler.'
                     'chance.ChanceScheduler')
diff --git a/nova/tests/network/test_manager.py b/nova/tests/network/test_manager.py
index b12d12167..2c04806b7 100644
--- a/nova/tests/network/test_manager.py
+++ b/nova/tests/network/test_manager.py
@@ -15,10 +15,11 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-import mox
 import shutil
 import tempfile
 
+import mox
+
 from nova import context
 from nova import db
 from nova.db.sqlalchemy import models
@@ -1998,7 +1999,7 @@ class LdapDNSTestCase(test.TestCase):
     def setUp(self):
         super(LdapDNSTestCase, self).setUp()
 
-        self.stub_module('ldap', fake_ldap)
+        self.useFixture(test.ReplaceModule('ldap', fake_ldap))
         dns_class = 'nova.network.ldapdns.LdapDNS'
         self.driver = importutils.import_object(dns_class)
 
diff --git a/nova/tests/test_imagecache.py b/nova/tests/test_imagecache.py
index 2a927b362..bfa948ce5 100644
--- a/nova/tests/test_imagecache.py
+++ b/nova/tests/test_imagecache.py
@@ -763,7 +763,7 @@ class ImageCacheManagerTestCase(test.TestCase):
         def listdir(path):
             # The python coverage tool got angry with my overly broad mocks
             if not path.startswith('/instance_path'):
-                return orig_list(path)
+                return orig_listdir(path)
 
             if path == '/instance_path':
                 return ['instance-1', 'instance-2', 'instance-3', '_base']
diff --git a/nova/tests/test_test.py b/nova/tests/test_test.py
index f89a5bb94..2e045b2ac 100644
--- a/nova/tests/test_test.py
+++ b/nova/tests/test_test.py
@@ -30,7 +30,7 @@ class IsolationTestCase(test.TestCase):
 
     """
     def test_service_isolation(self):
-        self.start_service('compute')
+        self.useFixture(test.ServiceFixture('compute'))
 
     def test_rpc_consumer_isolation(self):
         class NeverCalled(object):
diff --git a/nova/tests/xenapi/stubs.py b/nova/tests/xenapi/stubs.py
index 560e12d70..ca8281295 100644
--- a/nova/tests/xenapi/stubs.py
+++ b/nova/tests/xenapi/stubs.py
@@ -352,6 +352,6 @@ class XenAPITestBase(test.TestCase):
     def setUp(self):
         super(XenAPITestBase, self).setUp()
 
-        self.stub_module('XenAPI', fake)
+        self.useFixture(test.ReplaceModule('XenAPI', fake))
 
         fake.reset()