text: # Copyright 2010-2011 OpenStack Foundation
  # 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.
  
  """Base Test Case for all Unit Tests"""
  
  import contextlib
  import gc
  import logging as std_logging
  import os
  import os.path
  import sys
  import weakref
  
  import eventlet.timeout
  import fixtures
  import mock
  from oslo.config import cfg
  from oslo.messaging import conffixture as messaging_conffixture
  import testtools
  
  from neutron.common import config
  from neutron.common import rpc as n_rpc
  from neutron.db import agentschedulers_db
  from neutron import manager
  from neutron.tests import fake_notifier
  from neutron.tests import post_mortem_debug
  
  
  CONF = cfg.CONF
  CONF.import_opt('state_path', 'neutron.common.config')
  TRUE_STRING = ['True', '1']
  LOG_FORMAT = "%(asctime)s %(levelname)8s [%(name)s] %(message)s"
  
  ROOTDIR = os.path.dirname(__file__)
  ETCDIR = os.path.join(ROOTDIR, 'etc')
  
  
  def etcdir(*p):
      return os.path.join(ETCDIR, *p)
  
  
  def fake_use_fatal_exceptions(*args):
      return True
  
  
  def fake_consume_in_threads(self):
      return []
  
  
  class BaseTestCase(testtools.TestCase):
  
      def cleanup_core_plugin(self):
          """Ensure that the core plugin is deallocated."""
          nm = manager.NeutronManager
          if not nm.has_instance():
              return
  
          #TODO(marun) Fix plugins that do not properly initialize notifiers
          agentschedulers_db.AgentSchedulerDbMixin.agent_notifiers = {}
  
          # Perform a check for deallocation only if explicitly
          # configured to do so since calling gc.collect() after every
          # test increases test suite execution time by ~50%.
          check_plugin_deallocation = (
              os.environ.get('OS_CHECK_PLUGIN_DEALLOCATION') in TRUE_STRING)
          if check_plugin_deallocation:
              plugin = weakref.ref(nm._instance.plugin)
  
          nm.clear_instance()
  
          if check_plugin_deallocation:
              gc.collect()
  
              #TODO(marun) Ensure that mocks are deallocated?
              if plugin() and not isinstance(plugin(), mock.Base):
                  self.fail('The plugin for this test was not deallocated.')
  
      def setup_coreplugin(self, core_plugin=None):
          if core_plugin is not None:
              cfg.CONF.set_override('core_plugin', core_plugin)
  
      def setup_notification_driver(self, notification_driver=None):
          self.addCleanup(fake_notifier.reset)
          if notification_driver is None:
              notification_driver = [fake_notifier.__name__]
          cfg.CONF.set_override("notification_driver", notification_driver)
  
      @staticmethod
      def config_parse(conf=None, args=None):
          """Create the default configurations."""
          # neutron.conf.test includes rpc_backend which needs to be cleaned up
          if args is None:
              args = ['--config-file', etcdir('neutron.conf.test')]
          if conf is None:
              config.init(args=args)
          else:
              conf(args)
  
      def setUp(self):
          super(BaseTestCase, self).setUp()
          # Ensure plugin cleanup is triggered last so that
          # test-specific cleanup has a chance to release references.
          self.addCleanup(self.cleanup_core_plugin)
  
          # Configure this first to ensure pm debugging support for setUp()
          if os.environ.get('OS_POST_MORTEM_DEBUG') in TRUE_STRING:
              self.addOnException(post_mortem_debug.exception_handler)
  
          if os.environ.get('OS_DEBUG') in TRUE_STRING:
              _level = std_logging.DEBUG
          else:
              _level = std_logging.INFO
          capture_logs = os.environ.get('OS_LOG_CAPTURE') in TRUE_STRING
          if not capture_logs:
              std_logging.basicConfig(format=LOG_FORMAT, level=_level)
          self.log_fixture = self.useFixture(
              fixtures.FakeLogger(
                  format=LOG_FORMAT,
                  level=_level,
                  nuke_handlers=capture_logs,
              ))
  
          # suppress all but errors here
          self.useFixture(
              fixtures.FakeLogger(
                  name='neutron.api.extensions',
                  format=LOG_FORMAT,
                  level=std_logging.ERROR,
                  nuke_handlers=capture_logs,
              ))
  
          test_timeout = int(os.environ.get('OS_TEST_TIMEOUT', 0))
          if test_timeout == -1:
              test_timeout = 0
          if test_timeout > 0:
              self.useFixture(fixtures.Timeout(test_timeout, gentle=True))
  
          # If someone does use tempfile directly, ensure that it's cleaned up
          self.useFixture(fixtures.NestedTempfile())
          self.useFixture(fixtures.TempHomeDir())
  
          self.temp_dir = self.useFixture(fixtures.TempDir()).path
          cfg.CONF.set_override('state_path', self.temp_dir)
  
          self.addCleanup(mock.patch.stopall)
          self.addCleanup(CONF.reset)
  
          if os.environ.get('OS_STDOUT_CAPTURE') in TRUE_STRING:
              stdout = self.useFixture(fixtures.StringStream('stdout')).stream
              self.useFixture(fixtures.MonkeyPatch('sys.stdout', stdout))
          if os.environ.get('OS_STDERR_CAPTURE') in TRUE_STRING:
              stderr = self.useFixture(fixtures.StringStream('stderr')).stream
              self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))
          self.useFixture(fixtures.MonkeyPatch(
              'neutron.common.exceptions.NeutronException.use_fatal_exceptions',
              fake_use_fatal_exceptions))
  
          # don't actually start RPC listeners when testing
          self.useFixture(fixtures.MonkeyPatch(
              'neutron.common.rpc.Connection.consume_in_threads',
              fake_consume_in_threads))
  
          self.useFixture(fixtures.MonkeyPatch(
              'oslo.messaging.Notifier', fake_notifier.FakeNotifier))
  
          self.messaging_conf = messaging_conffixture.ConfFixture(CONF)
          self.messaging_conf.transport_driver = 'fake'
          self.messaging_conf.response_timeout = 15
          self.useFixture(self.messaging_conf)
  
          self.addCleanup(n_rpc.clear_extra_exmods)
          n_rpc.add_extra_exmods('neutron.test')
  
          self.addCleanup(n_rpc.cleanup)
          n_rpc.init(CONF)
  
          if sys.version_info < (2, 7) and getattr(self, 'fmt', '') == 'xml':
              raise self.skipException('XML Testing Skipped in Py26')
  
          self.setup_config()
  
      def setup_config(self):
          """Tests that need a non-default config can override this method."""
          self.config_parse()
  
      def config(self, **kw):
          """Override some configuration values.
  
          The keyword arguments are the names of configuration options to
          override and their values.
  
          If a group argument is supplied, the overrides are applied to
          the specified configuration option group.
  
          All overrides are automatically cleared at the end of the current
          test by the fixtures cleanup process.
          """
          group = kw.pop('group', None)
          for k, v in kw.iteritems():
              CONF.set_override(k, v, group)
  
      @contextlib.contextmanager
      def assert_max_execution_time(self, max_execution_time=5):
          with eventlet.timeout.Timeout(max_execution_time, False):
              yield
              return
          self.fail('Execution of this test timed out')
  