compute node local_gb_used include swap disks

The ComputeNode.local_gb_used value is set in the ResourceTracker._update_usage() method, based on

1. root_gb in the flavor
2. any disk overhead from the virt driver
3. ephemeral_gb in the flavor

The consideration of swap disk in the flavor was ignored.

This patch adds swap disk to the consideration.

Closes-bug: #1782386

Change-Id: I880e9daa6b97d73a0e33ac9a5bdae9bacfa89aaa

nova/compute/resource_tracker.py

@@ -936,6 +936,7 @@ class ResourceTracker(object):
         cn.memory_mb_used += sign * mem_usage
         cn.local_gb_used += sign * disk_usage
         cn.local_gb_used += sign * usage.get('ephemeral_gb', 0)
+        cn.local_gb_used += sign * usage.get('swap', 0) / 1024
         cn.vcpus_used += sign * vcpus_usage
 
         # free ram and disk may be negative, depending on policy:
@@ -1457,6 +1458,7 @@ class ResourceTracker(object):
             is_bfv = compute_utils.is_volume_backed_instance(
                 object_or_dict._context, object_or_dict)
             usage = {'memory_mb': object_or_dict.flavor.memory_mb,
+                     'swap': object_or_dict.flavor.swap,
                      'vcpus': object_or_dict.flavor.vcpus,
                      'root_gb': (0 if is_bfv else
                                  object_or_dict.flavor.root_gb),

nova/tests/functional/test_servers.py

@@ -3649,9 +3649,7 @@ class VolumeBackedServerTest(integrated_helpers.ProviderUsageBaseTestCase):
         self.assertEqual(expected_usage, resources['DISK_GB'])
         # Ensure the compute node is reporting the correct disk usage
         self.assertEqual(
-            # TODO(efried): Due to bug #1782386, swap is not being reported.
-            # expected_usage,
-            30,
+            expected_usage,
             self.admin_api.get_hypervisor_stats()['local_gb_used'])
 
     def test_volume_backed_no_disk_allocation(self):
@@ -3664,9 +3662,7 @@ class VolumeBackedServerTest(integrated_helpers.ProviderUsageBaseTestCase):
         self.assertEqual(expected_usage, resources['DISK_GB'])
         # Ensure the compute node is reporting the correct disk usage
         self.assertEqual(
-            # TODO(efried): Due to bug #1782386, swap is not being reported.
-            # expected_usage,
-            20,
+            expected_usage,
             self.admin_api.get_hypervisor_stats()['local_gb_used'])
 
         # Now let's hack the RequestSpec.is_bfv field to mimic migrating an

nova/tests/unit/compute/test_resource_tracker.py

@@ -2684,6 +2684,15 @@ class TestUpdateUsageFromInstance(BaseTestCase):
         result = self.rt._get_usage_dict(self.instance)
         self.assertEqual(0, result['root_gb'])
 
+    @mock.patch('nova.compute.utils.is_volume_backed_instance')
+    def test_get_usage_dict_include_swap(
+            self, mock_check_bfv):
+        mock_check_bfv.return_value = False
+        instance_with_swap = self.instance.obj_clone()
+        instance_with_swap.flavor.swap = 10
+        result = self.rt._get_usage_dict(instance_with_swap)
+        self.assertEqual(10, result['swap'])
+
     @mock.patch('nova.compute.utils.is_volume_backed_instance')
     @mock.patch('nova.compute.resource_tracker.ResourceTracker.'
                 '_update_usage')