From 33d906a2e060447778e95449a78e6583f18afcfd Mon Sep 17 00:00:00 2001 From: Yingxin Date: Tue, 8 Dec 2015 13:47:32 +0000 Subject: [PATCH] Use stevedore for scheduler driver Avoid having to configure the full class path of scheduler driver, change to load by stevedore driver plugin using entrypoints. Change 'scheduler_driver' to use entrypoint with the namespace 'nova.scheduler.driver' in 'setup.cfg'. Meanwhile, still maintain the compatibility for class path configuration until the next major release. Change all related tests with flag 'scheduler_driver' to use stevedore entrypoint. UpgradeImpact - see the reno file attached. Implements: blueprint scheduler-driver-use-stevedore Change-Id: I8c169e12d9bfacdbdb1dadf68b8a1fa98c5ea5bc --- nova/conf/scheduler.py | 24 ++++--- nova/scheduler/manager.py | 28 ++++++++- nova/tests/functional/integrated_helpers.py | 3 +- .../functional/libvirt/test_numa_servers.py | 3 +- nova/tests/unit/scheduler/test_scheduler.py | 63 ++++++++++++++++++- ...fig_scheduler_driver-e751ae392bc1a1d0.yaml | 9 +++ setup.cfg | 6 ++ 7 files changed, 120 insertions(+), 16 deletions(-) create mode 100644 releasenotes/notes/config_scheduler_driver-e751ae392bc1a1d0.yaml diff --git a/nova/conf/scheduler.py b/nova/conf/scheduler.py index eaadc18c2634..8ac26bab7c59 100644 --- a/nova/conf/scheduler.py +++ b/nova/conf/scheduler.py @@ -270,20 +270,26 @@ and will be dropped in the N release. """) driver_opt = cfg.StrOpt("scheduler_driver", - default="nova.scheduler.filter_scheduler.FilterScheduler", + default="filter_scheduler", help=""" -The class of the driver used by the scheduler. This should be the full Python -path to the class to be used. If nothing is specified in this option, the -FilterScheduler is used. +The class of the driver used by the scheduler. This should be chosen from one +of the entrypoints under the namespace 'nova.scheduler.driver' of file +'setup.cfg'. If nothing is specified in this option, the 'filter_scheduler' is +used. + +This option also supports deprecated full Python path to the class to be used. +For example, "nova.scheduler.filter_scheduler.FilterScheduler". But note: this +support will be dropped in the N Release. Other options are: - * 'nova.scheduler.caching_scheduler.CachingScheduler' which aggressively - caches the system state for better individual scheduler performance at - the risk of more retries when running multiple schedulers. + * 'caching_scheduler' which aggressively caches the system state for better + individual scheduler performance at the risk of more retries when running + multiple schedulers. - * 'nova.scheduler.chance.ChanceScheduler' which simply picks a host at - random. + * 'chance_scheduler' which simply picks a host at random. + + * 'fake_scheduler' which is used for testing. * Services that use this: diff --git a/nova/scheduler/manager.py b/nova/scheduler/manager.py index 7b246c8533d5..3c34034976db 100644 --- a/nova/scheduler/manager.py +++ b/nova/scheduler/manager.py @@ -19,18 +19,23 @@ Scheduler Service """ +from oslo_log import log as logging import oslo_messaging as messaging from oslo_serialization import jsonutils from oslo_service import periodic_task from oslo_utils import importutils +from stevedore import driver import nova.conf from nova import exception +from nova.i18n import _, _LW from nova import manager from nova import objects from nova import quota +LOG = logging.getLogger(__name__) + CONF = nova.conf.CONF QUOTAS = quota.QUOTAS @@ -46,7 +51,28 @@ class SchedulerManager(manager.Manager): def __init__(self, scheduler_driver=None, *args, **kwargs): if not scheduler_driver: scheduler_driver = CONF.scheduler_driver - self.driver = importutils.import_object(scheduler_driver) + try: + self.driver = driver.DriverManager( + "nova.scheduler.driver", + scheduler_driver, + invoke_on_load=True).driver + # TODO(Yingxin): Change to catch stevedore.exceptions.NoMatches after + # stevedore v1.9.0 + except RuntimeError: + # NOTE(Yingxin): Loading full class path is deprecated and should + # be removed in the N release. + try: + self.driver = importutils.import_object(scheduler_driver) + LOG.warning(_LW("DEPRECATED: scheduler_driver uses " + "classloader to load %(path)s. This legacy " + "loading style will be removed in the " + "N release."), + {'path': scheduler_driver}) + except (ImportError, ValueError): + raise RuntimeError( + _("Cannot load scheduler driver from configuration " + "%(conf)s."), + {'conf': scheduler_driver}) super(SchedulerManager, self).__init__(service_name='scheduler', *args, **kwargs) diff --git a/nova/tests/functional/integrated_helpers.py b/nova/tests/functional/integrated_helpers.py index c5e25c6d92a8..bb890d86adec 100644 --- a/nova/tests/functional/integrated_helpers.py +++ b/nova/tests/functional/integrated_helpers.py @@ -92,8 +92,7 @@ class _IntegratedTestBase(test.TestCase): return self.start_service('compute') def _setup_scheduler_service(self): - self.flags(scheduler_driver='nova.scheduler.' - 'chance.ChanceScheduler') + self.flags(scheduler_driver='chance_scheduler') return self.start_service('scheduler') def _setup_services(self): diff --git a/nova/tests/functional/libvirt/test_numa_servers.py b/nova/tests/functional/libvirt/test_numa_servers.py index cd7e0e6a77c0..52d1a5691580 100644 --- a/nova/tests/functional/libvirt/test_numa_servers.py +++ b/nova/tests/functional/libvirt/test_numa_servers.py @@ -79,8 +79,7 @@ class NUMAServersTest(ServersTestBase): def _setup_scheduler_service(self): self.flags(compute_driver='nova.virt.libvirt.LibvirtDriver') - self.flags(scheduler_driver='nova.scheduler.' - 'filter_scheduler.FilterScheduler') + self.flags(scheduler_driver='filter_scheduler') self.flags(scheduler_default_filters=CONF.scheduler_default_filters + ['NUMATopologyFilter']) return self.start_service('scheduler') diff --git a/nova/tests/unit/scheduler/test_scheduler.py b/nova/tests/unit/scheduler/test_scheduler.py index 7f2e2c0cf3bf..078b067dd8d6 100644 --- a/nova/tests/unit/scheduler/test_scheduler.py +++ b/nova/tests/unit/scheduler/test_scheduler.py @@ -21,7 +21,10 @@ import mock from nova import context from nova import objects +from nova.scheduler import caching_scheduler +from nova.scheduler import chance from nova.scheduler import driver +from nova.scheduler import filter_scheduler from nova.scheduler import host_manager from nova.scheduler import ironic_host_manager from nova.scheduler import manager @@ -31,18 +34,74 @@ from nova.tests.unit import fake_server_actions from nova.tests.unit.scheduler import fakes +class SchedulerManagerInitTestCase(test.NoDBTestCase): + """Test case for scheduler manager initiation.""" + manager_cls = manager.SchedulerManager + + @mock.patch.object(host_manager.HostManager, '_init_instance_info') + @mock.patch.object(host_manager.HostManager, '_init_aggregates') + def test_init_using_default_schedulerdriver(self, + mock_init_agg, + mock_init_inst): + driver = self.manager_cls().driver + self.assertIsInstance(driver, filter_scheduler.FilterScheduler) + + @mock.patch.object(host_manager.HostManager, '_init_instance_info') + @mock.patch.object(host_manager.HostManager, '_init_aggregates') + def test_init_using_chance_schedulerdriver(self, + mock_init_agg, + mock_init_inst): + self.flags(scheduler_driver='chance_scheduler') + driver = self.manager_cls().driver + self.assertIsInstance(driver, chance.ChanceScheduler) + + @mock.patch.object(host_manager.HostManager, '_init_instance_info') + @mock.patch.object(host_manager.HostManager, '_init_aggregates') + def test_init_using_caching_schedulerdriver(self, + mock_init_agg, + mock_init_inst): + self.flags(scheduler_driver='caching_scheduler') + driver = self.manager_cls().driver + self.assertIsInstance(driver, caching_scheduler.CachingScheduler) + + @mock.patch.object(host_manager.HostManager, '_init_instance_info') + @mock.patch.object(host_manager.HostManager, '_init_aggregates') + def test_init_nonexist_schedulerdriver(self, + mock_init_agg, + mock_init_inst): + self.flags(scheduler_driver='nonexist_scheduler') + self.assertRaises(RuntimeError, self.manager_cls) + + # NOTE(Yingxin): Loading full class path is deprecated and should be + # removed in the N release. + @mock.patch.object(manager.LOG, 'warning') + @mock.patch.object(host_manager.HostManager, '_init_instance_info') + @mock.patch.object(host_manager.HostManager, '_init_aggregates') + def test_init_using_classpath_to_schedulerdriver(self, + mock_init_agg, + mock_init_inst, + mock_warning): + self.flags( + scheduler_driver= + 'nova.scheduler.chance.ChanceScheduler') + driver = self.manager_cls().driver + self.assertIsInstance(driver, chance.ChanceScheduler) + warn_args, kwargs = mock_warning.call_args + self.assertIn("DEPRECATED", warn_args[0]) + + class SchedulerManagerTestCase(test.NoDBTestCase): """Test case for scheduler manager.""" manager_cls = manager.SchedulerManager driver_cls = fakes.FakeScheduler - driver_cls_name = 'nova.tests.unit.scheduler.fakes.FakeScheduler' + driver_plugin_name = 'fake_scheduler' @mock.patch.object(host_manager.HostManager, '_init_instance_info') @mock.patch.object(host_manager.HostManager, '_init_aggregates') def setUp(self, mock_init_agg, mock_init_inst): super(SchedulerManagerTestCase, self).setUp() - self.flags(scheduler_driver=self.driver_cls_name) + self.flags(scheduler_driver=self.driver_plugin_name) with mock.patch.object(host_manager.HostManager, '_init_aggregates'): self.manager = self.manager_cls() self.context = context.RequestContext('fake_user', 'fake_project') diff --git a/releasenotes/notes/config_scheduler_driver-e751ae392bc1a1d0.yaml b/releasenotes/notes/config_scheduler_driver-e751ae392bc1a1d0.yaml new file mode 100644 index 000000000000..c1837411eace --- /dev/null +++ b/releasenotes/notes/config_scheduler_driver-e751ae392bc1a1d0.yaml @@ -0,0 +1,9 @@ +--- +upgrade: + - | + The option ``scheduler_driver`` is now changed to use entrypoint instead of + full class path. Set one of the entrypoints under the namespace + 'nova.scheduler.driver' in 'setup.cfg'. Its default value is + 'host_manager'. The full class path style is still supported in current + release. But it is not recommended because class path can be changed and + this support will be dropped in the next major release. diff --git a/setup.cfg b/setup.cfg index 39fee7358741..f6848e2ecbbe 100644 --- a/setup.cfg +++ b/setup.cfg @@ -191,6 +191,12 @@ nova.scheduler.host_manager = host_manager = nova.scheduler.host_manager:HostManager ironic_host_manager = nova.scheduler.ironic_host_manager:IronicHostManager +nova.scheduler.driver = + filter_scheduler = nova.scheduler.filter_scheduler:FilterScheduler + caching_scheduler = nova.scheduler.caching_scheduler:CachingScheduler + chance_scheduler = nova.scheduler.chance:ChanceScheduler + fake_scheduler = nova.tests.unit.scheduler.fakes:FakeScheduler + [build_sphinx] all_files = 1 build-dir = doc/build