Allow enabling metrics per virtual disk

This change will allow enabling metrics for individual virtual disks.
The Nova Hyper-V driver will use it when attaching Cinder volumes.

Note that Hyper-V does not support collecting metrics for passthrough
disks at the moment.

Change-Id: Iaba32ca94b2c09661f150fa4b12b2c7eb83ff6d9
Partial-Bug: #1794456

os_win/tests/unit/utils/metrics/test_metricsutils.py

@@ -18,7 +18,9 @@ import mock
 from os_win import exceptions
 from os_win.tests.unit import test_base
 from os_win.utils import _wqlutils
+from os_win.utils.compute import vmutils
 from os_win.utils.metrics import metricsutils
+from os_win import utilsfactory
 
 
 class MetricsUtilsTestCase(test_base.OsWinBaseTestCase):
@@ -27,8 +29,16 @@ class MetricsUtilsTestCase(test_base.OsWinBaseTestCase):
     _FAKE_RET_VAL = 0
     _FAKE_PORT = "fake's port name"
 
+    _autospec_classes = [
+        vmutils.VMUtils,
+    ]
+
     def setUp(self):
         super(MetricsUtilsTestCase, self).setUp()
+
+        mock.patch.object(utilsfactory, 'get_vmutils',
+                          mock.Mock(return_value=vmutils.VMUtils)).start()
+
         self.utils = metricsutils.MetricsUtils()
         self.utils._conn_attr = mock.MagicMock()
 
@@ -58,6 +68,22 @@ class MetricsUtilsTestCase(test_base.OsWinBaseTestCase):
         mock_enable_metrics.assert_has_calls(
             [mock.call(mock_disk), mock.call(mock_vm, metrics_names)])
 
+    @mock.patch.object(metricsutils.MetricsUtils, '_enable_metrics')
+    def test_enable_disk_metrics_collection(self, mock_enable_metrics):
+        mock_get_disk = (
+            self.utils._vmutils._get_mounted_disk_resource_from_path)
+
+        self.utils.enable_disk_metrics_collection(
+            mock.sentinel.disk_path,
+            mock.sentinel.is_physical,
+            mock.sentinel.serial)
+
+        mock_get_disk.assert_called_once_with(
+            mock.sentinel.disk_path,
+            is_physical=mock.sentinel.is_physical,
+            serial=mock.sentinel.serial)
+        mock_enable_metrics.assert_called_once_with(mock_get_disk.return_value)
+
     @mock.patch.object(metricsutils.MetricsUtils, '_enable_metrics')
     @mock.patch.object(metricsutils.MetricsUtils, '_get_switch_port')
     def test_enable_switch_port_metrics_collection(self, mock_get_port,

os_win/utils/metrics/metricsutils.py

@@ -57,6 +57,10 @@ class MetricsUtils(baseutils.BaseUtilsVirt):
         self._metrics_svc_obj = None
         self._metrics_defs_obj = {}
 
+        # We need to avoid a circular dependency.
+        from os_win import utilsfactory
+        self._vmutils = utilsfactory.get_vmutils(host)
+
     @property
     def _metrics_svc(self):
         if not self._metrics_svc_obj:
@@ -87,6 +91,13 @@ class MetricsUtils(baseutils.BaseUtilsVirt):
         metrics_names = [self._CPU_METRICS, self._MEMORY_METRICS]
         self._enable_metrics(vm, metrics_names)
 
+    def enable_disk_metrics_collection(self, attached_disk_path=None,
+                                       is_physical=False,
+                                       serial=None):
+        disk = self._vmutils._get_mounted_disk_resource_from_path(
+            attached_disk_path, is_physical=is_physical, serial=serial)
+        self._enable_metrics(disk)
+
     def enable_port_metrics_collection(self, switch_port_name):
         port = self._get_switch_port(switch_port_name)
         metrics_names = [self._NET_IN_METRICS, self._NET_OUT_METRICS]