Add device_label tag in addition to label tag. (#8306)

This makes labels a bit more consistent with agent's builtin io check,
which uses device_label.

Author: Slavek Kabrda

disk/datadog_checks/disk/disk.py

@@ -152,7 +152,7 @@ def check(self, instance):
                     tags.extend(device_tags)
 
             if self.devices_label.get(device_name):
-                tags.append(self.devices_label.get(device_name))
+                tags.extend(self.devices_label.get(device_name))
 
             # legacy check names c: vs psutil name C:\\
             if Platform.is_win32():
@@ -316,7 +316,7 @@ def collect_latency_metrics(self):
                 metric_tags.append('device:{}'.format(disk_name))
                 metric_tags.append('device_name:{}'.format(_base_device_name(disk_name)))
                 if self.devices_label.get(disk_name):
-                    metric_tags.append(self.devices_label.get(disk_name))
+                    metric_tags.extend(self.devices_label.get(disk_name))
                 self.rate(self.METRIC_DISK.format('read_time_pct'), read_time_pct, tags=metric_tags)
                 self.rate(self.METRIC_DISK.format('write_time_pct'), write_time_pct, tags=metric_tags)
             except AttributeError as e:
@@ -422,7 +422,7 @@ def _get_devices_label_from_blkid(self):
                 # /dev/sda1: LABEL="MYLABEL" UUID="5eea373d-db36-4ce2-8c71-12ce544e8559" TYPE="ext4"
                 labels = self._blkid_label_re.findall(d[1])
                 if labels:
-                    devices_label[d[0]] = 'label:{}'.format(labels[0])
+                    devices_label[d[0]] = ['label:{}'.format(labels[0]), 'device_label:{}'.format(labels[0])]
 
         except SubprocessOutputEmptyError:
             self.log.debug("Couldn't use blkid to have device labels")
@@ -446,7 +446,7 @@ def _get_devices_label_from_blkid_cache(self):
                 device = root.text
                 label = root.attrib.get('LABEL')
                 if label and device:
-                    devices_label[device] = 'label:{}'.format(label)
+                    devices_label[device] = ['label:{}'.format(label), 'device_label:{}'.format(label)]
             except ET.ParseError as e:
                 self.log.warning(
                     'Failed to parse line %s because of %s - skipping the line (some labels might be missing)', line, e

disk/tests/test_unit.py

@@ -127,7 +127,7 @@ def test_device_tagging(aggregator, gauge_metrics, rate_metrics):
     with mock.patch('datadog_checks.disk.disk.Disk._get_devices_label'):
         # _get_devices_label is only called on linux, so devices_label is manually filled
         # to make the test run on everything
-        c.devices_label = {DEFAULT_DEVICE_NAME: 'label:mylab'}
+        c.devices_label = {DEFAULT_DEVICE_NAME: ['label:mylab', 'device_label:mylab']}
         c.check(instance)
 
     # Assert metrics
@@ -138,6 +138,7 @@ def test_device_tagging(aggregator, gauge_metrics, rate_metrics):
         'device_name:{}'.format(DEFAULT_DEVICE_BASE_NAME),
         'optional:tags1',
         'label:mylab',
+        'device_label:mylab',
     ]
 
     for name, value in iteritems(gauge_metrics):
@@ -152,6 +153,7 @@ def test_device_tagging(aggregator, gauge_metrics, rate_metrics):
                 'device_name:{}'.format(DEFAULT_DEVICE_BASE_NAME),
                 'optional:tags1',
                 'label:mylab',
+                'device_label:mylab',
             ],
         )
 
@@ -167,7 +169,7 @@ def test_get_devices_label():
         __name__='get_subprocess_output',
     ):
         labels = c._get_devices_label()
-        assert labels.get("/dev/mapper/vagrant--vg-root") == "label:DATA"
+        assert labels.get("/dev/mapper/vagrant--vg-root") == ["label:DATA", "device_label:DATA"]
 
 
 @pytest.mark.usefixtures('psutil_mocks')
@@ -199,7 +201,9 @@ def test_labels_from_blkid_cache_file(aggregator, instance_blkid_cache_file, gau
     c = Disk('disk', {}, [instance_blkid_cache_file])
     c.check(instance_blkid_cache_file)
     for metric in chain(gauge_metrics, rate_metrics):
-        aggregator.assert_metric(metric, tags=['device:/dev/sda1', 'device_name:sda1', 'label:MYLABEL'])
+        aggregator.assert_metric(
+            metric, tags=['device:/dev/sda1', 'device_name:sda1', 'label:MYLABEL', 'device_label:MYLABEL']
+        )
 
 
 @pytest.mark.skipif(not Platform.is_linux(), reason='disk labels are only available on Linux')