From 42422a1d16e2aba2963e8ca5edecf11862376344 Mon Sep 17 00:00:00 2001
From: Roman Bednar <rbednar@redhat.com>
Date: Fri, 16 Sep 2022 10:43:38 +0200
Subject: [PATCH] add a metric for retroactive sc errors

---
 .../persistentvolume/metrics/metrics.go       | 28 +++++++++++++++++++
 .../volume/persistentvolume/pv_controller.go  |  2 ++
 2 files changed, 30 insertions(+)

diff --git a/pkg/controller/volume/persistentvolume/metrics/metrics.go b/pkg/controller/volume/persistentvolume/metrics/metrics.go
index 86ca21ff76e..22f25792def 100644
--- a/pkg/controller/volume/persistentvolume/metrics/metrics.go
+++ b/pkg/controller/volume/persistentvolume/metrics/metrics.go
@@ -65,6 +65,8 @@ func Register(pvLister PVLister, pvcLister PVCLister, pluginMgr *volume.VolumePl
 	registerMetrics.Do(func() {
 		legacyregistry.CustomMustRegister(newPVAndPVCCountCollector(pvLister, pvcLister, pluginMgr))
 		legacyregistry.MustRegister(volumeOperationErrorsMetric)
+		legacyregistry.MustRegister(retroactiveStorageClassMetric)
+		legacyregistry.MustRegister(retroactiveStorageClassErrorMetric)
 	})
 }
 
@@ -122,6 +124,20 @@ var (
 			StabilityLevel: metrics.ALPHA,
 		},
 		[]string{"plugin_name", "operation_name"})
+
+	retroactiveStorageClassMetric = metrics.NewCounter(
+		&metrics.CounterOpts{
+			Name:           "retroactive_storageclass_total",
+			Help:           "Total number of retroactive StorageClass assignments to persistent volume claim",
+			StabilityLevel: metrics.ALPHA,
+		})
+
+	retroactiveStorageClassErrorMetric = metrics.NewCounter(
+		&metrics.CounterOpts{
+			Name:           "retroactive_storageclass_errors_total",
+			Help:           "Total number of failed retroactive StorageClass assignments to persistent volume claim",
+			StabilityLevel: metrics.ALPHA,
+		})
 )
 
 // volumeCount counts by PluginName and VolumeMode.
@@ -231,6 +247,18 @@ func (collector *pvAndPVCCountCollector) pvcCollect(ch chan<- metrics.Metric) {
 	}
 }
 
+// RecordRetroactiveStorageClassMetric increments only retroactive_storageclass_total
+// metric or both retroactive_storageclass_total and retroactive_storageclass_errors_total
+// if success is false.
+func RecordRetroactiveStorageClassMetric(success bool) {
+	if !success {
+		retroactiveStorageClassMetric.Inc()
+		retroactiveStorageClassErrorMetric.Inc()
+	} else {
+		retroactiveStorageClassMetric.Inc()
+	}
+}
+
 // RecordVolumeOperationErrorMetric records error count into metric
 // volume_operation_total_errors for provisioning/deletion operations
 func RecordVolumeOperationErrorMetric(pluginName, opName string) {
diff --git a/pkg/controller/volume/persistentvolume/pv_controller.go b/pkg/controller/volume/persistentvolume/pv_controller.go
index ca98f91caaf..08e4fd9c2de 100644
--- a/pkg/controller/volume/persistentvolume/pv_controller.go
+++ b/pkg/controller/volume/persistentvolume/pv_controller.go
@@ -355,10 +355,12 @@ func (ctrl *PersistentVolumeController) syncUnboundClaim(ctx context.Context, cl
 				klog.V(4).Infof("FeatureGate[%s] is enabled, attempting to assign storage class to unbound PersistentVolumeClaim[%s]", features.RetroactiveDefaultStorageClass, claimToClaimKey(claim))
 				updated, err := ctrl.assignDefaultStorageClass(claim)
 				if err != nil {
+					metrics.RecordRetroactiveStorageClassMetric(false)
 					return fmt.Errorf("can't update PersistentVolumeClaim[%q]: %w", claimToClaimKey(claim), err)
 				}
 				if updated {
 					klog.V(4).Infof("PersistentVolumeClaim[%q] update successful, restarting claim sync", claimToClaimKey(claim))
+					metrics.RecordRetroactiveStorageClassMetric(true)
 					return nil
 				}
 			}