Stop ignoring missing compute nodes in claims

The resource tracker will silently ignore attempts to claim resources
when the node requested is not managed by this host. The misleading
"self.disabled(nodename)" check will fail if the nodename is not known
to the resource tracker, causing us to bail early with a NopClaim.
That means we also don't do additional setup like creating a migration
context for the instance, claim resources in placement, and handle
PCI/NUMA things. This behavior is quite old, and clearly doesn't make
sense in a world with things like placement. The bulk of the test
changes here are due to the fact that a lot of tests were relying on
this silent ignoring of a mismatching node, because they were passing
node names that weren't even tracked.

This change makes us raise an error if this happens so that we can
actually catch it, and avoid silently continuing with no resource
claim.

Change-Id: I416126ee5d10428c296fe618aa877cca0e8dffcf

1 files changed, 12 insertions, 7 deletions

diff --git a/nova/tests/unit/compute/test_resource_tracker.py b/nova/tests/unit/compute/test_resource_tracker.py
index cd36b8987f..b6770cb5b8 100644
--- a/nova/tests/unit/compute/test_resource_tracker.py
+++ b/nova/tests/unit/compute/test_resource_tracker.py
@@ -2231,14 +2231,19 @@ class TestInstanceClaim(BaseTestCase):
         self.rt.compute_nodes = {}
         self.assertTrue(self.rt.disabled(_NODENAME))
 
-        with mock.patch.object(self.instance, 'save'):
-            claim = self.rt.instance_claim(mock.sentinel.ctx, self.instance,
-                                           _NODENAME, self.allocations, None)
+        # Reset all changes to the instance to make sure that we can detect
+        # any manipulation after the failure.
+        self.instance.obj_reset_changes(recursive=True)
 
-        self.assertEqual(self.rt.host, self.instance.host)
-        self.assertEqual(self.rt.host, self.instance.launched_on)
-        self.assertEqual(_NODENAME, self.instance.node)
-        self.assertIsInstance(claim, claims.NopClaim)
+        with mock.patch.object(self.instance, 'save') as mock_save:
+            self.assertRaises(exc.ComputeResourcesUnavailable,
+                              self.rt.instance_claim,
+                              mock.sentinel.ctx, self.instance,
+                              _NODENAME, self.allocations, None)
+            mock_save.assert_not_called()
+
+        # Make sure the instance was not touched by the failed claim process
+        self.assertEqual(set(), self.instance.obj_what_changed())
 
     @mock.patch('nova.compute.utils.is_volume_backed_instance')
     @mock.patch('nova.objects.MigrationList.get_in_progress_and_error')