Merge pull request #2370 from ricardoapl/kube_persistentvolume_volume_mode

feat: add kube_persistentvolume_volume_mode metric

Author: k8s-ci-robot

docs/metrics/storage/persistentvolume-metrics.md

@@ -11,6 +11,7 @@
 | kube_persistentvolume_created            | Gauge       | Unix creation timestamp                                                                                                   | seconds                 | `persistentvolume`=&lt;persistentvolume-name&gt; <br>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | EXPERIMENTAL |
 | kube_persistentvolume_deletion_timestamp | Gauge       | Unix deletion timestamp                                                                                                   | seconds                 | `persistentvolume`=&lt;persistentvolume-name&gt; <br>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | EXPERIMENTAL |
 | kube_persistentvolume_csi_attributes     | Gauge       | CSI attributes of the Persistent Volume, disabled by default, manage with [--metric-opt-in-list](../../developer/cli-arguments.md))     |                         | `persistentvolume`=&lt;persistentvolume-name&gt; <br> `csi_mounter`=&lt;csi-mounter&gt; <br> `csi_map_options`=&lt;csi-map-options&gt;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | EXPERIMENTAL |
+| kube_persistentvolume_volume_mode       | Gauge       | Volume Mode information for the PersistentVolume.                                                                          |                         | `persistentvolume`=&lt;persistentvolume-name&gt; <br>`volumemode`=&lt;volumemode&gt;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   | EXPERIMENTAL       |
 
 ## Useful metrics queries