Remove global state from the FakeDriver

The virt driver FakeDriver used in both the functional and in the unit
test used a global state to configure the host and node names the driver
reports. This was hard to use when more then one compute service is started.
Also global state is dangerous.

It turned out that only a set of unit tests are using multiple nodes per
compute the rest of the tests can simply use host=<hostname>,
nodes=[<hostname>] setup.

So this removes the global state.

Change-Id: I2cf2fcbaebc706f897ce5dfbff47d32117064f9c
(cherry picked from commit b5666fb)

Author: Balazs Gibizer

doc/api_samples/os-hypervisors/v2.53/hypervisors-list-resp.json

@@ -1,7 +1,7 @@
 {
     "hypervisors": [
         {
-            "hypervisor_hostname": "fake-mini",
+            "hypervisor_hostname": "host2",
             "id": "1bb62a04-c576-402c-8147-9e89757a09e3",
             "state": "up",
             "status": "enabled"

nova/test.py

@@ -419,6 +419,12 @@ def flags(self, **kw):
 
     def start_service(self, name, host=None, **kwargs):
         cell = None
+        # if the host is None then the CONF.host remains defaulted to
+        # 'fake-mini' (originally done in ConfFixture)
+        if host is not None:
+            # Make sure that CONF.host is relevant to the right hostname
+            self.useFixture(nova_fixtures.ConfPatcher(host=host))
+
         if name == 'compute' and self.USES_DB:
             # NOTE(danms): We need to create the HostMapping first, because
             # otherwise we'll fail to update the scheduler while running
@@ -431,9 +437,6 @@ def start_service(self, name, host=None, **kwargs):
                                      cell_mapping=cell)
             hm.create()
             self.host_mappings[hm.host] = hm
-            if host is not None:
-                # Make sure that CONF.host is relevant to the right hostname
-                self.useFixture(nova_fixtures.ConfPatcher(host=host))
         svc = self.useFixture(
             nova_fixtures.ServiceFixture(name, host, cell=cell, **kwargs))
 

nova/tests/functional/api_sample_tests/api_samples/os-hypervisors/v2.53/hypervisors-list-resp.json.tpl

@@ -1,7 +1,7 @@
 {
     "hypervisors": [
         {
-            "hypervisor_hostname": "fake-mini",
+            "hypervisor_hostname": "host2",
             "id": "%(hypervisor_id)s",
             "state": "up",
             "status": "enabled"

nova/tests/functional/api_sample_tests/test_hypervisors.py

@@ -18,7 +18,6 @@
 from nova.cells import utils as cells_utils
 from nova import objects
 from nova.tests.functional.api_sample_tests import api_sample_base
-from nova.virt import fake
 
 
 class HypervisorsSampleJsonTests(api_sample_base.ApiSampleTestBaseV21):
@@ -157,8 +156,6 @@ def setUp(self):
         # Start a new compute service to fake a record with hypervisor id=2
         # for pagination test.
         host = 'host1'
-        fake.set_nodes([host])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host=host)
 
     def test_hypervisors_list(self):
@@ -205,8 +202,6 @@ def test_hypervisors_list(self):
     def test_hypervisors_detail(self):
         # Start another compute service to get a 2nd compute for paging tests.
         host = 'host2'
-        fake.set_nodes([host])
-        self.addCleanup(fake.restore_nodes)
         service_2 = self.start_service('compute', host=host).service_ref
         compute_node_2 = service_2.compute_node
         marker = self.compute_node_1.uuid

nova/tests/functional/compute/test_live_migration.py

@@ -20,7 +20,6 @@
 from nova.tests.functional import integrated_helpers
 from nova.tests.unit import fake_notifier
 from nova.tests import uuidsentinel as uuids
-from nova.virt import fake
 
 
 class FakeCinderError(object):
@@ -53,8 +52,6 @@ def setUp(self):
         # Start a second compte node (the first one was started for us by
         # _IntegratedTestBase. set_nodes() is needed to avoid duplicate
         # nodenames. See comments in test_bug_1702454.py.
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.compute2 = self.start_service('compute', host='host2')
 
     # To get the old Cinder flow we need to hack the service version, otherwise

nova/tests/functional/integrated_helpers.py

@@ -35,7 +35,6 @@
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
 from nova.tests import uuidsentinel as uuids
-from nova.virt import fake
 
 
 CONF = nova.conf.CONF
@@ -396,8 +395,6 @@ def _start_compute(self, host, cell_name=None):
                           compute service (defaults to cell1)
         :return: the nova compute service object
         """
-        fake.set_nodes([host])
-        self.addCleanup(fake.restore_nodes)
         compute = self.start_service('compute', host=host, cell=cell_name)
         self.computes[host] = compute
         return compute

nova/tests/functional/notification_sample_tests/test_instance.py

@@ -22,7 +22,6 @@
 from nova.tests.functional.notification_sample_tests \
     import notification_sample_base
 from nova.tests.unit import fake_notifier
-from nova.virt import fake
 
 COMPUTE_VERSION_OLD_ATTACH_FLOW = \
     compute_api.CINDER_V3_ATTACH_MIN_COMPUTE_VERSION - 1
@@ -48,8 +47,6 @@ def test_multiple_compute_actions(self):
         self._wait_for_notification('instance.create.end')
         self._attach_volume_to_server(server, self.cinder.SWAP_OLD_VOL)
         # server will boot on the 'compute' host
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.compute2 = self.start_service('compute', host='host2')
 
         actions = [

nova/tests/functional/regressions/test_bug_1669054.py

@@ -13,7 +13,6 @@
 from nova import context
 from nova import objects
 from nova.tests.functional import integrated_helpers
-from nova.virt import fake
 
 
 class ResizeEvacuateTestCase(integrated_helpers._IntegratedTestBase,
@@ -47,8 +46,6 @@ def test_resize_then_evacuate(self):
         self._wait_for_state_change(self.api, server, 'ACTIVE')
 
         # Start up another compute service so we can resize.
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         host2 = self.start_service('compute', host='host2')
 
         # Now resize the server to move it to host2.

nova/tests/functional/regressions/test_bug_1671648.py

@@ -22,7 +22,6 @@
 from nova.tests.unit import fake_network
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestRetryBetweenComputeNodeBuilds(test.TestCase):
@@ -67,17 +66,7 @@ def setUp(self):
 
         # We start two compute services because we're going to fake one
         # of them to fail the build so we can trigger the retry code.
-        # set_nodes() is needed to have each compute service return a
-        # different nodename, so we get two hosts in the list of candidates
-        # for scheduling. Otherwise both hosts will have the same default
-        # nodename "fake-mini". The host passed to start_service controls the
-        # "host" attribute and set_nodes() sets the "nodename" attribute.
-        # We set_nodes() to make host and nodename the same for each compute.
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host2')
 
         self.useFixture(cast_as_call.CastAsCall(self))

nova/tests/functional/regressions/test_bug_1702454.py

@@ -17,7 +17,6 @@
 from nova.tests.unit import cast_as_call
 from nova.tests.unit.image import fake as image_fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class HostNameWeigher(weights.BaseHostWeigher):
@@ -99,20 +98,8 @@ def setUp(self):
         self.start_service('scheduler')
 
         # Let's now start three compute nodes as we said above.
-        # set_nodes() is needed to have each compute service return a
-        # different nodename, so we get two hosts in the list of candidates
-        # for scheduling. Otherwise both hosts will have the same default
-        # nodename "fake-mini". The host passed to start_service controls the
-        # "host" attribute and set_nodes() sets the "nodename" attribute.
-        # We set_nodes() to make host and nodename the same for each compute.
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host2')
-        fake.set_nodes(['host3'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host3')
         self.useFixture(cast_as_call.CastAsCall(self))
 

nova/tests/functional/regressions/test_bug_1718455.py

@@ -18,7 +18,6 @@
 from nova.tests.unit import fake_network
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestLiveMigrateOneOfConcurrentlyCreatedInstances(
@@ -60,17 +59,7 @@ def setUp(self):
         self.start_service('conductor')
         self.start_service('scheduler')
 
-        # set_nodes() is needed to have each compute service return a
-        # different nodename, so we get two hosts in the list of candidates
-        # for scheduling. Otherwise both hosts will have the same default
-        # nodename "fake-mini". The host passed to start_service controls the
-        # "host" attribute and set_nodes() sets the "nodename" attribute.
-        # We set_nodes() to make host and nodename the same for each compute.
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host2')
 
         fake_network.set_stub_network_methods(self)

nova/tests/functional/regressions/test_bug_1718512.py

@@ -19,7 +19,6 @@
 from nova.tests.functional import integrated_helpers
 from nova.tests.unit.image import fake as image_fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class HostNameWeigher(weights.BaseHostWeigher):
@@ -86,8 +85,6 @@ def setUp(self):
 
         # Let's now start three compute nodes as we said above.
         for host in ['host1', 'host2', 'host3']:
-            fake.set_nodes([host])
-            self.addCleanup(fake.restore_nodes)
             self.start_service('compute', host=host)
 
     def _stub_resize_failure(self, failed_host):

nova/tests/functional/regressions/test_bug_1719730.py

@@ -17,7 +17,6 @@
 from nova.tests.unit import fake_network
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestRescheduleWithServerGroup(test.TestCase,
@@ -64,11 +63,7 @@ def setUp(self):
 
         # We start two compute services because we're going to fake one raising
         # RescheduledException to trigger a retry to the other compute host.
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host2')
 
         self.image_id = self.api.get_images()[0]['id']

nova/tests/functional/regressions/test_bug_1735407.py

@@ -17,7 +17,6 @@
 from nova.tests.unit import fake_notifier
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestParallelEvacuationWithServerGroup(
@@ -57,11 +56,7 @@ def setUp(self):
 
         # We start two compute services because we need two instances with
         # anti-affinity server group policy to be booted
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.compute1 = self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.compute2 = self.start_service('compute', host='host2')
 
         self.image_id = self.api.get_images()[0]['id']
@@ -122,8 +117,6 @@ def test_parallel_evacuate_with_server_group(self):
         self.api.force_down_service('host2', 'nova-compute', True)
 
         # start a third compute to have place for one of the instances
-        fake.set_nodes(['host3'])
-        self.addCleanup(fake.restore_nodes)
         self.compute3 = self.start_service('compute', host='host3')
 
         # evacuate both instances

nova/tests/functional/regressions/test_bug_1741307.py

@@ -15,7 +15,6 @@
 from nova.tests.functional import integrated_helpers
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestResizeWithCachingScheduler(test.TestCase,
@@ -65,8 +64,6 @@ def setUp(self):
 
         # Create two compute nodes/services.
         for host in ('host1', 'host2'):
-            fake.set_nodes([host])
-            self.addCleanup(fake.restore_nodes)
             self.start_service('compute', host=host)
 
         flavors = self.api.get_flavors()

nova/tests/functional/regressions/test_bug_1746483.py

@@ -17,7 +17,6 @@
 from nova.tests.unit.image import fake as image_fakes
 from nova.tests.unit import policy_fixture
 from nova import utils
-from nova.virt import fake
 
 CONF = config.CONF
 
@@ -67,8 +66,6 @@ def setUp(self):
         # Create two compute nodes/services so we can restrict the image
         # we'll use to one of the hosts.
         for host in ('host1', 'host2'):
-            fake.set_nodes([host])
-            self.addCleanup(fake.restore_nodes)
             self.start_service('compute', host=host)
 
     def test_boot_from_volume_with_isolated_image(self):

nova/tests/functional/regressions/test_bug_1764556.py

@@ -18,7 +18,6 @@
 from nova.tests.unit.image import fake as fake_image
 from nova.tests.unit import policy_fixture
 from nova import utils
-from nova.virt import fake as fake_virt
 
 
 class InstanceListWithDeletedServicesTestCase(
@@ -50,7 +49,6 @@ def setUp(self):
 
         # the image fake backend needed for image discovery
         fake_image.stub_out_image_service(self)
-        self.addCleanup(fake_image.FakeImageService_reset)
         # Get the image before we set the microversion to latest to avoid
         # the proxy issues with GET /images in 2.36.
         self.image_id = self.api.get_images()[0]['id']
@@ -83,8 +81,6 @@ def test_instance_list_deleted_service_with_no_uuid(self):
         5. migrate the instance back to the host1 service
         6. list instances which will try to online migrate the old service uuid
         """
-        fake_virt.set_nodes(['host1'])
-        self.addCleanup(fake_virt.restore_nodes)
         host1 = self.start_service('compute', host='host1')
 
         # Create an instance which will be on host1 since it's the only host.
@@ -96,8 +92,6 @@ def test_instance_list_deleted_service_with_no_uuid(self):
 
         # Now we start a 2nd compute which is "upgraded" (has a uuid) and
         # we'll migrate the instance to that host.
-        fake_virt.set_nodes(['host2'])
-        self.addCleanup(fake_virt.restore_nodes)
         host2 = self.start_service('compute', host='host2')
         self.assertIsNotNone(host2.service_ref.uuid)
 

nova/tests/functional/regressions/test_bug_1764883.py

@@ -18,7 +18,6 @@
 from nova.tests.unit import fake_notifier
 import nova.tests.unit.image.fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class TestEvacuationWithSourceReturningDuringRebuild(
@@ -62,12 +61,8 @@ def setUp(self):
         # Start two computes
         self.computes = {}
 
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.computes['host1'] = self.start_service('compute', host='host1')
 
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.computes['host2'] = self.start_service('compute', host='host2')
 
         self.image_id = self.api.get_images()[0]['id']

nova/tests/functional/regressions/test_bug_1781710.py

@@ -17,7 +17,6 @@
 from nova.tests.functional import integrated_helpers
 from nova.tests.unit.image import fake as image_fake
 from nova.tests.unit import policy_fixture
-from nova.virt import fake
 
 
 class HostNameWeigher(weights.BaseHostWeigher):
@@ -76,11 +75,7 @@ def setUp(self):
                    group='workarounds')
         self.start_service('scheduler')
 
-        fake.set_nodes(['host1'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host1')
-        fake.set_nodes(['host2'])
-        self.addCleanup(fake.restore_nodes)
         self.start_service('compute', host='host2')
 
     def test_anti_affinity_multi_create(self):