Add volume reconstruction metrics

Count nr. of volumes that kubelet tried to reconstruct + reconstruction
errors.

pkg/kubelet/volumemanager/metrics/metrics.go

@@ -30,7 +30,9 @@ const (
 	pluginNameNotAvailable = "N/A"
 
 	// Metric keys for Volume Manager.
-	volumeManagerTotalVolumes = "volume_manager_total_volumes"
+	volumeManagerTotalVolumes       = "volume_manager_total_volumes"
+	reconstructedVolumesTotal       = "reconstructed_volumes_total"
+	reconstructedVolumesErrorsTotal = "reconstructed_volumes_errors_total"
 )
 
 var (
@@ -43,6 +45,21 @@ var (
 		nil,
 		metrics.ALPHA, "",
 	)
+
+	ReconstructedVolumesTotal = metrics.NewCounter(
+		&metrics.CounterOpts{
+			Name:           reconstructedVolumesTotal,
+			Help:           "The number of volumes that were attempted to be reconstructed from the operating system during kubelet startup. This includes both successful and failed reconstruction.",
+			StabilityLevel: metrics.ALPHA,
+		},
+	)
+	ReconstructedVolumesErrorsTotal = metrics.NewCounter(
+		&metrics.CounterOpts{
+			Name:           reconstructedVolumesErrorsTotal,
+			Help:           "The number of volumes that failed reconstruction from the operating system during kubelet startup.",
+			StabilityLevel: metrics.ALPHA,
+		},
+	)
 )
 
 // volumeCount is a map of maps used as a counter.
@@ -61,6 +78,8 @@ func (v volumeCount) add(state, plugin string) {
 func Register(asw cache.ActualStateOfWorld, dsw cache.DesiredStateOfWorld, pluginMgr *volume.VolumePluginMgr) {
 	registerMetrics.Do(func() {
 		legacyregistry.CustomMustRegister(&totalVolumesCollector{asw: asw, dsw: dsw, pluginMgr: pluginMgr})
+		legacyregistry.MustRegister(ReconstructedVolumesTotal)
+		legacyregistry.MustRegister(ReconstructedVolumesErrorsTotal)
 	})
 }
 

pkg/kubelet/volumemanager/reconciler/reconstruct_common.go

@@ -28,6 +28,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/klog/v2"
 	"k8s.io/kubernetes/pkg/kubelet/config"
+	"k8s.io/kubernetes/pkg/kubelet/volumemanager/metrics"
 	volumepkg "k8s.io/kubernetes/pkg/volume"
 	"k8s.io/kubernetes/pkg/volume/util"
 	"k8s.io/kubernetes/pkg/volume/util/operationexecutor"
@@ -177,7 +178,14 @@ func getVolumesFromPodDir(podDir string) ([]podVolume, error) {
 }
 
 // Reconstruct volume data structure by reading the pod's volume directories
-func (rc *reconciler) reconstructVolume(volume podVolume) (*reconstructedVolume, error) {
+func (rc *reconciler) reconstructVolume(volume podVolume) (rvolume *reconstructedVolume, rerr error) {
+	metrics.ReconstructedVolumesTotal.Inc()
+	defer func() {
+		if rerr != nil {
+			metrics.ReconstructedVolumesErrorsTotal.Inc()
+		}
+	}()
+
 	// plugin initializations
 	plugin, err := rc.volumePluginMgr.FindPluginByName(volume.pluginName)
 	if err != nil {