Merge "Add service version check workaround for FFU" into stable/wallaby

Author: Zuul

nova/api/openstack/wsgi_app.py

@@ -44,7 +44,13 @@ def _get_config_files(env=None):
 
 
 def _setup_service(host, name):
-    utils.raise_if_old_compute()
+    try:
+        utils.raise_if_old_compute()
+    except exception.TooOldComputeService as e:
+        if CONF.workarounds.disable_compute_service_check_for_ffu:
+            LOG.warning(str(e))
+        else:
+            raise
 
     binary = name if name.startswith('nova-') else "nova-%s" % name
 

nova/conf/workarounds.py

@@ -435,6 +435,16 @@
 Related options:
 
 * :oslo.config:option:`DEFAULT.compute_driver` (libvirt)
+"""),
+    cfg.BoolOpt('disable_compute_service_check_for_ffu',
+                default=False,
+                help="""
+If this is set, the normal safety check for old compute services will be
+treated as a warning instead of an error. This is only to be enabled to
+facilitate a Fast-Forward upgrade where new control services are being started
+before compute nodes have been able to update their service record. In an FFU,
+the service records in the database will be more than one version old until
+the compute nodes start up, but control services need to be online first.
 """),
 ]
 

nova/service.py

@@ -261,7 +261,13 @@ def create(cls, host=None, binary=None, topic=None, manager=None,
         # up before it allows the service to be created. The
         # raise_if_old_compute() depends on the RPC to be up and does not
         # implement its own retry mechanism to connect to the conductor.
-        utils.raise_if_old_compute()
+        try:
+            utils.raise_if_old_compute()
+        except exception.TooOldComputeService as e:
+            if CONF.workarounds.disable_compute_service_check_for_ffu:
+                LOG.warning(str(e))
+            else:
+                raise
 
         return service_obj
 

nova/tests/unit/api/openstack/test_wsgi_app.py

@@ -18,6 +18,7 @@
 from oslotest import base
 
 from nova.api.openstack import wsgi_app
+from nova import exception
 from nova import test
 from nova.tests import fixtures as nova_fixtures
 
@@ -83,3 +84,19 @@ def test_init_application_called_twice(self, mock_get_files, mock_setup,
         wsgi_app.init_application('nova-api')
         self.assertIn('Global data already initialized, not re-initializing.',
                       self.stdlog.logger.output)
+
+    @mock.patch('nova.objects.Service.get_by_host_and_binary')
+    @mock.patch('nova.utils.raise_if_old_compute')
+    def test_setup_service_version_workaround(self, mock_check_old, mock_get):
+        mock_check_old.side_effect = exception.TooOldComputeService(
+            oldest_supported_version='2',
+            scope='scope',
+            min_service_level=2,
+            oldest_supported_service=1)
+
+        self.assertRaises(exception.TooOldComputeService,
+                          wsgi_app._setup_service, 'myhost', 'api')
+        wsgi_app.CONF.set_override(
+            'disable_compute_service_check_for_ffu', True,
+            group='workarounds')
+        wsgi_app._setup_service('myhost', 'api')

nova/tests/unit/test_service.py

@@ -286,6 +286,29 @@ def fake_wait(*args, **kwargs):
         mock_check_old.assert_called_once_with()
         mock_wait.assert_called_once_with(mock.ANY)
 
+    @mock.patch('nova.utils.raise_if_old_compute')
+    def test_old_compute_version_check_workaround(
+            self, mock_check_old):
+
+        mock_check_old.side_effect = exception.TooOldComputeService(
+            oldest_supported_version='2',
+            scope='scope',
+            min_service_level=2,
+            oldest_supported_service=1)
+
+        self.assertRaises(exception.TooOldComputeService,
+                          service.Service.create,
+                          self.host, 'nova-conductor', self.topic,
+                          'nova.tests.unit.test_service.FakeManager')
+
+        CONF.set_override('disable_compute_service_check_for_ffu', True,
+                          group='workarounds')
+
+        service.Service.create(self.host, 'nova-conductor', self.topic,
+                               'nova.tests.unit.test_service.FakeManager')
+
+        mock_check_old.assert_has_calls([mock.call(), mock.call()])
+
 
 class TestWSGIService(test.NoDBTestCase):