Merge "Verify requested_destination in the scheduler"

nova/scheduler/host_manager.py

@@ -505,10 +505,33 @@ class HostManager(object):
                           "'force_nodes' value of '%s'")
             LOG.info(msg % forced_nodes_str)
 
+        def _get_hosts_matching_request(hosts, requested_destination):
+            (host, node) = (requested_destination.host,
+                            requested_destination.node)
+            requested_nodes = [x for x in hosts
+                               if x.host == host and x.nodename == node]
+            if requested_nodes:
+                LOG.info(_LI('Host filter only checking host %(host)s and '
+                             'node %(node)s') % {'host': host, 'node': node})
+            else:
+                # NOTE(sbauza): The API level should prevent the user from
+                # providing a wrong destination but let's make sure a wrong
+                # destination doesn't trample the scheduler still.
+                LOG.info(_LI('No hosts matched due to not matching requested '
+                             'destination (%(host)s, %(node)s)'
+                             ) % {'host': host, 'node': node})
+            return iter(requested_nodes)
+
         ignore_hosts = spec_obj.ignore_hosts or []
         force_hosts = spec_obj.force_hosts or []
         force_nodes = spec_obj.force_nodes or []
+        requested_node = spec_obj.requested_destination
 
+        if requested_node is not None:
+            # NOTE(sbauza): Reduce a potentially long set of hosts as much as
+            # possible to any requested destination nodes before passing the
+            # list to the filters
+            hosts = _get_hosts_matching_request(hosts, requested_node)
         if ignore_hosts or force_hosts or force_nodes:
             # NOTE(deva): we can't assume "host" is unique because
             #             one host may have many nodes.

nova/tests/unit/scheduler/test_host_manager.py

@@ -222,6 +222,40 @@ class HostManagerTestCase(test.NoDBTestCase):
                 fake_properties)
         self._verify_result(info, result)
 
+    def test_get_filtered_hosts_with_requested_destination(self):
+        dest = objects.Destination(host='fake_host1', node='fake-node')
+        fake_properties = objects.RequestSpec(requested_destination=dest,
+                                              ignore_hosts=[],
+                                              instance_uuid='fake-uuid1',
+                                              force_hosts=[],
+                                              force_nodes=[])
+
+        info = {'expected_objs': [self.fake_hosts[0]],
+                'expected_fprops': fake_properties}
+
+        self._mock_get_filtered_hosts(info)
+
+        result = self.host_manager.get_filtered_hosts(self.fake_hosts,
+                fake_properties)
+        self._verify_result(info, result)
+
+    def test_get_filtered_hosts_with_wrong_requested_destination(self):
+        dest = objects.Destination(host='dummy', node='fake-node')
+        fake_properties = objects.RequestSpec(requested_destination=dest,
+                                              ignore_hosts=[],
+                                              instance_uuid='fake-uuid1',
+                                              force_hosts=[],
+                                              force_nodes=[])
+
+        info = {'expected_objs': [],
+                'expected_fprops': fake_properties}
+
+        self._mock_get_filtered_hosts(info)
+
+        result = self.host_manager.get_filtered_hosts(self.fake_hosts,
+                fake_properties)
+        self._verify_result(info, result)
+
     def test_get_filtered_hosts_with_ignore(self):
         fake_properties = objects.RequestSpec(
             instance_uuid=uuids.instance,