Esempio n. 1
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(NoDBTestCase, self).setUp()
        self.useFixture(
            nova_fixtures.Timeout(os.environ.get('OS_TEST_TIMEOUT', 0),
                                  self.TIMEOUT_SCALING_FACTOR))

        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.useFixture(nova_fixtures.OutputStreamCapture())
        self.useFixture(nova_fixtures.StandardLogging())
        self.useFixture(conf_fixture.ConfFixture(CONF))

        # NOTE(blk-u): WarningsFixture must be after the Database fixture
        # because sqlalchemy-migrate messes with the warnings filters.
        self.useFixture(nova_fixtures.WarningsFixture())

        mox_fixture = self.useFixture(moxstubout.MoxStubout())
        self.mox = mox_fixture.mox
        self.stubs = mox_fixture.stubs
        self.addCleanup(self._clear_attrs)
        self.policy = self.useFixture(policy_fixture.PolicyFixture())

        self.useFixture(nova_fixtures.PoisonFunctions())
Esempio n. 2
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        self.useFixture(nova_fixtures.Timeout(
            os.environ.get('OS_TEST_TIMEOUT', 0),
            self.TIMEOUT_SCALING_FACTOR))

        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.useFixture(nova_fixtures.OutputStreamCapture())

        self.useFixture(nova_fixtures.StandardLogging())

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we ended up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path,
                                group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))
        self.useFixture(nova_fixtures.RPCFixture('nova.test'))

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObjectRegistry._registry._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        # NOTE(danms): Reset the cached list of cells
        from nova.compute import api
        api.CELLS = []

        self.cell_mappings = {}
        self.host_mappings = {}
        # NOTE(danms): If the test claims to want to set up the database
        # itself, then it is responsible for all the mapping stuff too.
        if self.USES_DB:
            # NOTE(danms): Full database setup involves a cell0, cell1,
            # and the relevant mappings.
            self.useFixture(nova_fixtures.Database(database='api'))
            self._setup_cells()
            self.useFixture(nova_fixtures.DefaultFlavorsFixture())
        elif not self.USES_DB_SELF:
            # NOTE(danms): If not using the database, we mock out the
            # mapping stuff and effectively collapse everything to a
            # single cell.
            self.useFixture(nova_fixtures.SingleCellSimple())
            self.useFixture(nova_fixtures.DatabasePoisonFixture())

        # NOTE(blk-u): WarningsFixture must be after the Database fixture
        # because sqlalchemy-migrate messes with the warnings filters.
        self.useFixture(nova_fixtures.WarningsFixture())

        self.useFixture(ovo_fixture.StableObjectJsonFixture())

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        mox_fixture = self.useFixture(moxstubout.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())

        self.useFixture(nova_fixtures.PoisonFunctions())

        openstack_driver.DRIVER_CACHE = {}

        self.useFixture(nova_fixtures.ForbidNewLegacyNotificationFixture())
Esempio n. 3
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        self.useFixture(
            nova_fixtures.Timeout(os.environ.get('OS_TEST_TIMEOUT', 0),
                                  self.TIMEOUT_SCALING_FACTOR))

        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.output = nova_fixtures.OutputStreamCapture()
        self.useFixture(self.output)

        self.stdlog = nova_fixtures.StandardLogging()
        self.useFixture(self.stdlog)

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we ended up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path, group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))

        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
        # happens only in the RPCFixture
        CONF.set_default('driver', ['test'],
                         group='oslo_messaging_notifications')

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObjectRegistry._registry._obj_classes)
        self.addCleanup(self._restore_obj_registry)
        objects.Service.clear_min_version_cache()

        # NOTE(danms): Reset the cached list of cells
        from nova.compute import api
        api.CELLS = []
        context.CELL_CACHE = {}
        context.CELLS = []

        self.cell_mappings = {}
        self.host_mappings = {}
        # NOTE(danms): If the test claims to want to set up the database
        # itself, then it is responsible for all the mapping stuff too.
        if self.USES_DB:
            # NOTE(danms): Full database setup involves a cell0, cell1,
            # and the relevant mappings.
            self.useFixture(nova_fixtures.Database(database='api'))
            self.useFixture(nova_fixtures.Database(database='placement'))
            self._setup_cells()
            self.useFixture(nova_fixtures.DefaultFlavorsFixture())
        elif not self.USES_DB_SELF:
            # NOTE(danms): If not using the database, we mock out the
            # mapping stuff and effectively collapse everything to a
            # single cell.
            self.useFixture(nova_fixtures.SingleCellSimple())
            self.useFixture(nova_fixtures.DatabasePoisonFixture())

        # NOTE(blk-u): WarningsFixture must be after the Database fixture
        # because sqlalchemy-migrate messes with the warnings filters.
        self.useFixture(nova_fixtures.WarningsFixture())

        self.useFixture(ovo_fixture.StableObjectJsonFixture())

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        # Reset the traits sync and rc cache flags
        def _reset_traits():
            resource_provider._TRAITS_SYNCED = False

        _reset_traits()
        self.addCleanup(_reset_traits)
        resource_provider._RC_CACHE = None
        # Reset the global QEMU version flag.
        images.QEMU_VERSION = None

        mox_fixture = self.useFixture(moxstubout.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())
        self.placement_policy = self.useFixture(
            policy_fixture.PlacementPolicyFixture())

        self.useFixture(nova_fixtures.PoisonFunctions())

        openstack_driver.DRIVER_CACHE = {}

        self.useFixture(nova_fixtures.ForbidNewLegacyNotificationFixture())

        # NOTE(mikal): make sure we don't load a privsep helper accidentally
        self.useFixture(nova_fixtures.PrivsepNoHelperFixture())
        self.useFixture(mock_fixture.MockAutospecFixture())

        # FIXME(danms): Disable this for all tests by default to avoid breaking
        # any that depend on default/previous ordering
        self.flags(build_failure_weight_multiplier=0.0,
                   group='filter_scheduler')
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        self.useFixture(
            nova_fixtures.Timeout(os.environ.get('OS_TEST_TIMEOUT', 0),
                                  self.TIMEOUT_SCALING_FACTOR))

        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.useFixture(nova_fixtures.OutputStreamCapture())

        self.useFixture(nova_fixtures.StandardLogging())

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we eneded up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path, group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))
        self.useFixture(nova_fixtures.RPCFixture('nova.test'))

        if self.USES_DB:
            self.useFixture(nova_fixtures.Database())
            self.useFixture(nova_fixtures.Database(database='api'))
            # NOTE(danms): Flavors are encoded in our original migration
            # which means we have no real option other than to migrate them
            # onlineish every time we build a new database (for now).
            ctxt = context.get_admin_context()
            flavor_obj.migrate_flavors(ctxt, 100, hard_delete=True)
        elif not self.USES_DB_SELF:
            self.useFixture(nova_fixtures.DatabasePoisonFixture())

        # NOTE(blk-u): WarningsFixture must be after the Database fixture
        # because sqlalchemy-migrate messes with the warnings filters.
        self.useFixture(nova_fixtures.WarningsFixture())

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObjectRegistry._registry._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        self.useFixture(nova_fixtures.StableObjectJsonFixture())

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        mox_fixture = self.useFixture(moxstubout.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())

        self.useFixture(nova_fixtures.PoisonFunctions())

        openstack_driver.DRIVER_CACHE = {}

        self.useFixture(nova_fixtures.ForbidNewLegacyNotificationFixture())
Esempio n. 5
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        # Ensure BaseTestCase's ConfigureLogging fixture is disabled since
        # we're using our own (StandardLogging).
        with fixtures.EnvironmentVariable('OS_LOG_CAPTURE', '0'):
            super(TestCase, self).setUp()

        # How many of which service we've started. {$service-name: $count}
        self._service_fixture_count = collections.defaultdict(int)

        self.useFixture(nova_fixtures.OpenStackSDKFixture())

        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.stdlog = self.useFixture(nova_fixtures.StandardLogging())

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we ended up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path,
                                group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))

        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
            # happens only in the RPCFixture
            CONF.set_default('driver', ['test'],
                             group='oslo_messaging_notifications')

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObjectRegistry._registry._obj_classes)
        self.addCleanup(self._restore_obj_registry)
        objects.Service.clear_min_version_cache()

        # NOTE(danms): Reset the cached list of cells
        from nova.compute import api
        api.CELLS = []
        context.CELL_CACHE = {}
        context.CELLS = []

        self.computes = {}
        self.cell_mappings = {}
        self.host_mappings = {}
        # NOTE(danms): If the test claims to want to set up the database
        # itself, then it is responsible for all the mapping stuff too.
        if self.USES_DB:
            # NOTE(danms): Full database setup involves a cell0, cell1,
            # and the relevant mappings.
            self.useFixture(nova_fixtures.Database(database='api'))
            self._setup_cells()
            self.useFixture(nova_fixtures.DefaultFlavorsFixture())
        elif not self.USES_DB_SELF:
            # NOTE(danms): If not using the database, we mock out the
            # mapping stuff and effectively collapse everything to a
            # single cell.
            self.useFixture(nova_fixtures.SingleCellSimple())
            self.useFixture(nova_fixtures.DatabasePoisonFixture())

        # NOTE(blk-u): WarningsFixture must be after the Database fixture
        # because sqlalchemy-migrate messes with the warnings filters.
        self.useFixture(nova_fixtures.WarningsFixture())

        self.useFixture(ovo_fixture.StableObjectJsonFixture())

        # Reset the global QEMU version flag.
        images.QEMU_VERSION = None

        # Reset the compute RPC API globals (mostly the _ROUTER).
        compute_rpcapi.reset_globals()

        self.addCleanup(self._clear_attrs)
        self.useFixture(fixtures.EnvironmentVariable('http_proxy'))
        self.policy = self.useFixture(policy_fixture.PolicyFixture())

        self.useFixture(nova_fixtures.PoisonFunctions())

        self.useFixture(nova_fixtures.ForbidNewLegacyNotificationFixture())

        # NOTE(mikal): make sure we don't load a privsep helper accidentally
        self.useFixture(nova_fixtures.PrivsepNoHelperFixture())
        self.useFixture(mock_fixture.MockAutospecFixture())

        # FIXME(danms): Disable this for all tests by default to avoid breaking
        # any that depend on default/previous ordering
        self.flags(build_failure_weight_multiplier=0.0,
                   group='filter_scheduler')

        # NOTE(melwitt): Reset the cached set of projects
        quota.UID_QFD_POPULATED_CACHE_BY_PROJECT = set()
        quota.UID_QFD_POPULATED_CACHE_ALL = False

        self.useFixture(nova_fixtures.GenericPoisonFixture())
Esempio n. 6
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        test_timeout = os.environ.get('OS_TEST_TIMEOUT', 0)
        try:
            test_timeout = int(test_timeout)
        except ValueError:
            # If timeout value is invalid do not set a timeout.
            test_timeout = 0

        if self.TIMEOUT_SCALING_FACTOR >= 0:
            test_timeout *= self.TIMEOUT_SCALING_FACTOR
        else:
            raise ValueError('TIMEOUT_SCALING_FACTOR value must be >= 0')

        if test_timeout > 0:
            self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(TranslationFixture())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        if os.environ.get('OS_STDOUT_CAPTURE') in _TRUE_VALUES:
            stdout = self.useFixture(fixtures.StringStream('stdout')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
        if os.environ.get('OS_STDERR_CAPTURE') in _TRUE_VALUES:
            stderr = self.useFixture(fixtures.StringStream('stderr')).stream
            self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))

        rpc.add_extra_exmods('nova.test')
        self.addCleanup(rpc.clear_extra_exmods)
        self.addCleanup(rpc.cleanup)

        # set root logger to debug
        root = logging.getLogger()
        root.setLevel(logging.DEBUG)

        # supports collecting debug level for local runs
        if os.environ.get('OS_DEBUG') in _TRUE_VALUES:
            level = logging.DEBUG
        else:
            level = logging.INFO

        # Collect logs
        fs = '%(asctime)s %(levelname)s [%(name)s] %(message)s'
        self.useFixture(fixtures.FakeLogger(format=fs, level=None))
        root.handlers[0].setLevel(level)

        if level > logging.DEBUG:
            # Just attempt to format debug level logs, but don't save them
            handler = NullHandler()
            self.useFixture(fixtures.LogHandler(handler, nuke_handlers=False))
            handler.setLevel(logging.DEBUG)

        # Don't log every single DB migration step
        logging.getLogger('migrate.versioning.api').setLevel(logging.WARNING)

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we eneded up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path, group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))

        self.messaging_conf = messaging_conffixture.ConfFixture(CONF)
        self.messaging_conf.transport_driver = 'fake'
        self.useFixture(self.messaging_conf)

        rpc.init(CONF)

        if self.USES_DB:
            global _DB_CACHE
            if not _DB_CACHE:
                _DB_CACHE = Database(session,
                                     migration,
                                     sql_connection=CONF.database.connection,
                                     sqlite_db=CONF.database.sqlite_db,
                                     sqlite_clean_db=CONF.sqlite_clean_db)

            self.useFixture(_DB_CACHE)

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObject._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        mox_fixture = self.useFixture(moxstubout.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())
        CONF.set_override('fatal_exception_format_errors', True)
        CONF.set_override('enabled', True, 'osapi_v3')
        CONF.set_override('force_dhcp_release', False)
        CONF.set_override('periodic_enable', False)
Esempio n. 7
0
    def setUp(self):
        """Run before each test method to initialize test environment."""
        super(TestCase, self).setUp()
        self.useFixture(
            nova_fixtures.Timeout(os.environ.get('OS_TEST_TIMEOUT', 0),
                                  self.TIMEOUT_SCALING_FACTOR))

        self.useFixture(fixtures.NestedTempfile())
        self.useFixture(fixtures.TempHomeDir())
        self.useFixture(nova_fixtures.TranslationFixture())
        self.useFixture(log_fixture.get_logging_handle_error_fixture())

        self.useFixture(nova_fixtures.OutputStreamCapture())

        self.useFixture(nova_fixtures.StandardLogging())

        rpc.add_extra_exmods('nova.test')
        self.addCleanup(rpc.clear_extra_exmods)
        self.addCleanup(rpc.cleanup)

        # NOTE(sdague): because of the way we were using the lock
        # wrapper we eneded up with a lot of tests that started
        # relying on global external locking being set up for them. We
        # consider all of these to be *bugs*. Tests should not require
        # global external locking, or if they do, they should
        # explicitly set it up themselves.
        #
        # The following REQUIRES_LOCKING class parameter is provided
        # as a bridge to get us there. No new tests should be added
        # that require it, and existing classes and tests should be
        # fixed to not need it.
        if self.REQUIRES_LOCKING:
            lock_path = self.useFixture(fixtures.TempDir()).path
            self.fixture = self.useFixture(
                config_fixture.Config(lockutils.CONF))
            self.fixture.config(lock_path=lock_path, group='oslo_concurrency')

        self.useFixture(conf_fixture.ConfFixture(CONF))

        self.messaging_conf = messaging_conffixture.ConfFixture(CONF)
        self.messaging_conf.transport_driver = 'fake'
        self.useFixture(self.messaging_conf)

        rpc.init(CONF)

        if self.USES_DB:
            self.useFixture(nova_fixtures.Database())

        # NOTE(danms): Make sure to reset us back to non-remote objects
        # for each test to avoid interactions. Also, backup the object
        # registry.
        objects_base.NovaObject.indirection_api = None
        self._base_test_obj_backup = copy.copy(
            objects_base.NovaObject._obj_classes)
        self.addCleanup(self._restore_obj_registry)

        # NOTE(mnaser): All calls to utils.is_neutron() are cached in
        # nova.utils._IS_NEUTRON.  We set it to None to avoid any
        # caching of that value.
        utils._IS_NEUTRON = None

        mox_fixture = self.useFixture(moxstubout.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())