Make _is_multi_host() use objects

This makes the network api _is_multi_host() method use objects
instead of direct database access so that compute manager can
call it directly.

Note that the previous unit tests for this method used the
random.choice() method to selectively test the is/is-not multihost
case. Unit tests should not be non-deterministic like this, for
coverage and stability reasons. This patch pulls out the two
possibilities for each into separate cases to ensure both are
tested.

Related to blueprint compute-manager-objects-juno

Change-Id: I432a759a666948f2cfaa29d82f749dc9a39141be

nova/network/api.py

@@ -24,7 +24,9 @@
 from nova.network import floating_ips
 from nova.network import model as network_model
 from nova.network import rpcapi as network_rpcapi
+from nova.objects import fixed_ip as fixed_ip_obj
 from nova.objects import instance as instance_obj
+from nova.objects import network as network_obj
 from nova.openstack.common.gettextutils import _
 from nova.openstack.common import log as logging
 from nova import policy
@@ -458,13 +460,14 @@ def setup_networks_on_host(self, context, instance, host=None,
 
     def _is_multi_host(self, context, instance):
         try:
-            fixed_ips = self.db.fixed_ip_get_by_instance(context,
-                                                         instance['uuid'])
+            fixed_ips = fixed_ip_obj.FixedIPList.get_by_instance_uuid(
+                context, instance['uuid'])
         except exception.FixedIpNotFoundForInstance:
             return False
-        network = self.db.network_get(context, fixed_ips[0]['network_id'],
-                                      project_only='allow_none')
-        return network['multi_host']
+        network = network_obj.Network.get_by_id(context,
+                                                fixed_ips[0].network_id,
+                                                project_only='allow_none')
+        return network.multi_host
 
     def _get_floating_ip_addresses(self, context, instance):
         floating_ips = self.db.instance_floating_address_get_all(context,

nova/tests/network/test_api.py

@@ -17,7 +17,6 @@
 
 import contextlib
 import itertools
-import random
 
 import mock
 import mox
@@ -32,6 +31,8 @@
 from nova.network import model as network_model
 from nova.network import rpcapi as network_rpcapi
 from nova.objects import fields
+from nova.objects import fixed_ip as fixed_ip_obj
+from nova.objects import network as network_obj
 from nova import policy
 from nova import test
 from nova.tests import fake_instance
@@ -235,46 +236,44 @@ def fake_fixed_ip_get_by_instance(ctxt, uuid):
         self.assertFalse(self.network_api._is_multi_host(self.context,
                                                          instance))
 
-    def test_is_multi_host_network_has_no_project_id(self):
-        is_multi_host = random.choice([True, False])
-        network = {'project_id': None,
-                   'multi_host': is_multi_host, }
-        network_ref = self.network_api.db.network_create_safe(
-                                                 self.context.elevated(),
-                                                 network)
-
-        def fake_fixed_ip_get_by_instance(ctxt, uuid):
-            fixed_ip = [{'network_id': network_ref['id'],
-                         'instance_uuid': FAKE_UUID, }]
-            return fixed_ip
-
-        self.stubs.Set(self.network_api.db, 'fixed_ip_get_by_instance',
-                       fake_fixed_ip_get_by_instance)
-
+    @mock.patch('nova.objects.fixed_ip.FixedIPList.get_by_instance_uuid')
+    @mock.patch('nova.objects.network.Network.get_by_id')
+    def _test_is_multi_host_network_has_no_project_id(self, is_multi_host,
+                                                      net_get, fip_get):
+        net_get.return_value = network_obj.Network(id=123,
+                                                   project_id=None,
+                                                   multi_host=is_multi_host)
+        fip_get.return_value = [fixed_ip_obj.FixedIP(
+                network_id=123, instance_uuid=FAKE_UUID)]
         instance = {'uuid': FAKE_UUID}
         result = self.network_api._is_multi_host(self.context, instance)
         self.assertEqual(is_multi_host, result)
 
-    def test_is_multi_host_network_has_project_id(self):
-        is_multi_host = random.choice([True, False])
-        network = {'project_id': self.context.project_id,
-                   'multi_host': is_multi_host, }
-        network_ref = self.network_api.db.network_create_safe(
-                                                 self.context.elevated(),
-                                                 network)
-
-        def fake_fixed_ip_get_by_instance(ctxt, uuid):
-            fixed_ip = [{'network_id': network_ref['id'],
-                         'instance_uuid': FAKE_UUID, }]
-            return fixed_ip
-
-        self.stubs.Set(self.network_api.db, 'fixed_ip_get_by_instance',
-                       fake_fixed_ip_get_by_instance)
-
+    def test_is_multi_host_network_has_no_project_id_multi(self):
+        self._test_is_multi_host_network_has_no_project_id(True)
+
+    def test_is_multi_host_network_has_no_project_id_non_multi(self):
+        self._test_is_multi_host_network_has_no_project_id(False)
+
+    @mock.patch('nova.objects.fixed_ip.FixedIPList.get_by_instance_uuid')
+    @mock.patch('nova.objects.network.Network.get_by_id')
+    def _test_is_multi_host_network_has_project_id(self, is_multi_host,
+                                                   net_get, fip_get):
+        net_get.return_value = network_obj.Network(
+            id=123, project_id=self.context.project_id,
+            multi_host=is_multi_host)
+        fip_get.return_value = [
+            fixed_ip_obj.FixedIP(network_id=123, instance_uuid=FAKE_UUID)]
         instance = {'uuid': FAKE_UUID}
         result = self.network_api._is_multi_host(self.context, instance)
         self.assertEqual(is_multi_host, result)
 
+    def test_is_multi_host_network_has_project_id_multi(self):
+        self._test_is_multi_host_network_has_project_id(True)
+
+    def test_is_multi_host_network_has_project_id_non_multi(self):
+        self._test_is_multi_host_network_has_project_id(False)
+
     def test_network_disassociate_project(self):
         def fake_network_disassociate(ctx, network_id, disassociate_host,
                                       disassociate_project):