Add get_available_node_uuids() to virt driver

This adds a get_available_node_uuids() method to the virt driver
interface. This aims to eventually replace the nodename-based
interface, but currently provides an implementation that will work
for most drivers. Any driver that does not override this method
will get the locally-persistent UUID from nova.virt.node.

Ironic obviously needs to override this (which is easy), as well as
the fake driver because it supports multiple nodes for testing. The
libvirt driver overrides it only because we test multiple libvirt
driver instances on a single host and we need each instantiation
of it to "capture" the UUID we have mocked out at the time it is
started.

Change-Id: Ibe14d2b223c737d82c217a74bc94e41603271a9d

10 files changed, 39 insertions, 6 deletions

diff --git a/nova/test.py b/nova/test.py
index f050dde3f9..4f3554d682 100644
--- a/nova/test.py
+++ b/nova/test.py
@@ -693,6 +693,7 @@ class SubclassSignatureTestCase(testtools.TestCase, metaclass=abc.ABCMeta):
         raise NotImplementedError()
 
     def setUp(self):
+        self.useFixture(nova_fixtures.ConfFixture(CONF))
         self.base = self._get_base_class()
 
         super(SubclassSignatureTestCase, self).setUp()
diff --git a/nova/tests/functional/compute/test_resource_tracker.py b/nova/tests/functional/compute/test_resource_tracker.py
index fff08697ae..139fb5e6ac 100644
--- a/nova/tests/functional/compute/test_resource_tracker.py
+++ b/nova/tests/functional/compute/test_resource_tracker.py
@@ -248,6 +248,7 @@ class IronicResourceTrackerTest(test.TestCase):
                 'numa_topology': None,
                 'resource_class': None,  # Act like admin hasn't set yet...
                 'stats': stats,
+                'uuid': str(getattr(uuids, nodename)),
             }
             self.rt.update_available_resource(self.ctx, nodename)
 
diff --git a/nova/tests/functional/libvirt/base.py b/nova/tests/functional/libvirt/base.py
index 47a8bbe81c..89fb0e51a5 100644
--- a/nova/tests/functional/libvirt/base.py
+++ b/nova/tests/functional/libvirt/base.py
@@ -18,6 +18,7 @@ import io
 from unittest import mock
 
 import fixtures
+from oslo_utils.fixture import uuidsentinel as uuids
 
 from nova import conf
 from nova.tests import fixtures as nova_fixtures
@@ -177,7 +178,9 @@ class ServersTestBase(integrated_helpers._IntegratedTestBase):
         self.assertNotIn(hostname, self.computes)
         self.assertNotIn(hostname, self.compute_rp_uuids)
 
-        self.computes[hostname] = _start_compute(hostname, host_info)
+        with mock.patch('nova.virt.node.get_local_node_uuid') as m:
+            m.return_value = str(getattr(uuids, 'node_%s' % hostname))
+            self.computes[hostname] = _start_compute(hostname, host_info)
 
         self.compute_rp_uuids[hostname] = self.placement.get(
             '/resource_providers?name=%s' % hostname).body[
diff --git a/nova/tests/functional/libvirt/test_evacuate.py b/nova/tests/functional/libvirt/test_evacuate.py
index 9d3deec99d..92d7ffba29 100644
--- a/nova/tests/functional/libvirt/test_evacuate.py
+++ b/nova/tests/functional/libvirt/test_evacuate.py
@@ -415,7 +415,9 @@ class _LibvirtEvacuateTest(integrated_helpers.InstanceHelperMixin):
 
         with mock.patch.object(fakelibvirt.Connection, 'getHostname',
                                return_value=name):
-            compute = self.start_service('compute', host=name)
+            with mock.patch('nova.virt.node.get_local_node_uuid') as m:
+                m.return_value = str(getattr(uuids, 'node_%s' % name))
+                compute = self.start_service('compute', host=name)
 
         compute.driver._host.get_connection().getHostname = lambda: name
         return compute
diff --git a/nova/tests/functional/libvirt/test_vpmem.py b/nova/tests/functional/libvirt/test_vpmem.py
index d1cad0e376..1200f80357 100644
--- a/nova/tests/functional/libvirt/test_vpmem.py
+++ b/nova/tests/functional/libvirt/test_vpmem.py
@@ -12,9 +12,11 @@
 #    under the License.
 
 import fixtures
+from unittest import mock
 
 from oslo_config import cfg
 from oslo_log import log as logging
+from oslo_utils.fixture import uuidsentinel as uuids
 
 from nova import objects
 from nova.tests import fixtures as nova_fixtures
@@ -99,7 +101,9 @@ class VPMEMTestBase(integrated_helpers.LibvirtProviderUsageBaseTestCase):
                                            cpu_cores=2, cpu_threads=2),
             hostname=hostname)
         self.mock_conn.return_value = fake_connection
-        compute = self._start_compute(host=hostname)
+        with mock.patch('nova.virt.node.get_local_node_uuid') as m:
+            m.return_value = str(getattr(uuids, 'node_%s' % hostname))
+            compute = self._start_compute(host=hostname)
 
         # Ensure populating the existing pmems correctly.
         vpmems = compute.driver._vpmems_by_name
diff --git a/nova/virt/driver.py b/nova/virt/driver.py
index 532ed1fa50..b6297bb785 100644
--- a/nova/virt/driver.py
+++ b/nova/virt/driver.py
@@ -34,6 +34,7 @@ from nova import context as nova_context
 from nova.i18n import _
 from nova import objects
 from nova.virt import event as virtevent
+import nova.virt.node
 
 CONF = nova.conf.CONF
 LOG = logging.getLogger(__name__)
@@ -1595,6 +1596,9 @@ class ComputeDriver(object):
         """
         raise NotImplementedError()
 
+    def get_available_node_uuids(self, refresh=False):
+        return [nova.virt.node.get_local_node_uuid()]
+
     def node_is_available(self, nodename):
         """Return whether this compute service manages a particular node."""
         if nodename in self.get_available_nodes():
diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 362bf89973..af59c6c027 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -32,6 +32,7 @@ import fixtures
 import os_resource_classes as orc
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
+from oslo_utils.fixture import uuidsentinel as uuids
 from oslo_utils import versionutils
 
 from nova.compute import power_state
@@ -160,8 +161,8 @@ class FakeDriver(driver.ComputeDriver):
         self._host = host
         # NOTE(gibi): this is unnecessary complex and fragile but this is
         # how many current functional sample tests expect the node name.
-        self._nodes = (['fake-mini'] if self._host == 'compute'
-                       else [self._host])
+        self._set_nodes(['fake-mini'] if self._host == 'compute'
+                        else [self._host])
 
     def _set_nodes(self, nodes):
         # NOTE(gibi): this is not part of the driver interface but used
@@ -646,6 +647,9 @@ class FakeDriver(driver.ComputeDriver):
     def get_available_nodes(self, refresh=False):
         return self._nodes
 
+    def get_available_node_uuids(self, refresh=False):
+        return [str(getattr(uuids, n)) for n in self.get_available_nodes()]
+
     def instance_on_disk(self, instance):
         return False
 
@@ -764,7 +768,7 @@ class PredictableNodeUUIDDriver(SmallFakeDriver):
             PredictableNodeUUIDDriver, self).get_available_resource(nodename)
         # This is used in ComputeNode.update_from_virt_driver which is called
         # from the ResourceTracker when creating a ComputeNode.
-        resources['uuid'] = uuid.uuid5(uuid.NAMESPACE_DNS, nodename)
+        resources['uuid'] = str(uuid.uuid5(uuid.NAMESPACE_DNS, nodename))
         return resources
 
 
diff --git a/nova/virt/ironic/driver.py b/nova/virt/ironic/driver.py
index 117294ff89..b437b4a959 100644
--- a/nova/virt/ironic/driver.py
+++ b/nova/virt/ironic/driver.py
@@ -839,6 +839,9 @@ class IronicDriver(virt_driver.ComputeDriver):
 
         return node_uuids
 
+    def get_available_node_uuids(self, refresh=False):
+        return self.get_available_nodes(refresh=refresh)
+
     def update_provider_tree(self, provider_tree, nodename, allocations=None):
         """Update a ProviderTree object with current resource provider and
         inventory information.
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index dbc9bc3f1e..e4c997c171 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -11317,6 +11317,9 @@ class LibvirtDriver(driver.ComputeDriver):
     def get_available_nodes(self, refresh=False):
         return [self._host.get_hostname()]
 
+    def get_available_node_uuids(self, refresh=False):
+        return [self._host.get_node_uuid()]
+
     def get_host_cpu_stats(self):
         """Return the current CPU state of the host."""
         return self._host.get_cpu_stats()
diff --git a/nova/virt/libvirt/host.py b/nova/virt/libvirt/host.py
index 46435a9a7f..4a8bf6f2ac 100644
--- a/nova/virt/libvirt/host.py
+++ b/nova/virt/libvirt/host.py
@@ -66,6 +66,7 @@ from nova.virt.libvirt import event as libvirtevent
 from nova.virt.libvirt import guest as libvirt_guest
 from nova.virt.libvirt import migration as libvirt_migrate
 from nova.virt.libvirt import utils as libvirt_utils
+import nova.virt.node  # noqa
 
 if ty.TYPE_CHECKING:
     import libvirt
@@ -138,6 +139,7 @@ class Host(object):
         self._caps = None
         self._domain_caps = None
         self._hostname = None
+        self._node_uuid = None
 
         self._wrapped_conn = None
         self._wrapped_conn_lock = threading.Lock()
@@ -1059,6 +1061,12 @@ class Host(object):
                       {'old': self._hostname, 'new': hostname})
         return self._hostname
 
+    def get_node_uuid(self):
+        """Returns the UUID of this node."""
+        if not self._node_uuid:
+            self._node_uuid = nova.virt.node.get_local_node_uuid()
+        return self._node_uuid
+
     def find_secret(self, usage_type, usage_id):
         """Find a secret.