add new metrics (gauges): backup_total and restore_total

Signed-off-by: fabito <fuechi@ciandt.com>

changelogs/unreleased/1353-fabito

@@ -0,0 +1 @@
+Add gauge metrics for number of existing backups and restores

pkg/controller/backup_controller.go

@@ -111,6 +111,8 @@ func NewBackupController(
 		backupLocationInformer.Informer().HasSynced,
 		volumeSnapshotLocationInformer.Informer().HasSynced,
 	)
+	c.resyncFunc = c.resync
+	c.resyncPeriod = time.Minute
 
 	backupInformer.Informer().AddEventHandler(
 		cache.ResourceEventHandlerFuncs{
@@ -141,6 +143,15 @@ func NewBackupController(
 	return c
 }
 
+func (c *backupController) resync() {
+	backups, err := c.lister.List(labels.Everything())
+	if err != nil {
+		c.logger.Error(err, "Error computing backup_total metric")
+	} else {
+		c.metrics.SetBackupTotal(int64(len(backups)))
+	}
+}
+
 func (c *backupController) processBackup(key string) error {
 	log := c.logger.WithField("key", key)
 

pkg/controller/restore_controller.go

@@ -25,6 +25,7 @@ import (
 	"io/ioutil"
 	"os"
 	"sort"
+	"time"
 
 	jsonpatch "github.com/evanphx/json-patch"
 	"github.com/pkg/errors"
@@ -133,6 +134,8 @@ func NewRestoreController(
 		backupLocationInformer.Informer().HasSynced,
 		snapshotLocationInformer.Informer().HasSynced,
 	)
+	c.resyncFunc = c.resync
+	c.resyncPeriod = time.Minute
 
 	restoreInformer.Informer().AddEventHandler(
 		cache.ResourceEventHandlerFuncs{
@@ -163,6 +166,15 @@ func NewRestoreController(
 	return c
 }
 
+func (c *restoreController) resync() {
+	restores, err := c.restoreLister.List(labels.Everything())
+	if err != nil {
+		c.logger.Error(err, "Error computing restore_total metric")
+	} else {
+		c.metrics.SetRestoreTotal(int64(len(restores)))
+	}
+}
+
 func (c *restoreController) processQueueItem(key string) error {
 	log := c.logger.WithField("key", key)
 

pkg/metrics/metrics.go

@@ -30,6 +30,7 @@ type ServerMetrics struct {
 const (
 	metricNamespace              = "velero"
 	backupTarballSizeBytesGauge  = "backup_tarball_size_bytes"
+	backupTotal                  = "backup_total"
 	backupAttemptTotal           = "backup_attempt_total"
 	backupSuccessTotal           = "backup_success_total"
 	backupFailureTotal           = "backup_failure_total"
@@ -37,6 +38,7 @@ const (
 	backupDeletionAttemptTotal   = "backup_deletion_attempt_total"
 	backupDeletionSuccessTotal   = "backup_deletion_success_total"
 	backupDeletionFailureTotal   = "backup_deletion_failure_total"
+	restoreTotal                 = "restore_total"
 	restoreAttemptTotal          = "restore_attempt_total"
 	restoreValidationFailedTotal = "restore_validation_failed_total"
 	restoreSuccessTotal          = "restore_success_total"
@@ -63,6 +65,13 @@ func NewServerMetrics() *ServerMetrics {
 				},
 				[]string{scheduleLabel},
 			),
+			backupTotal: prometheus.NewGauge(
+				prometheus.GaugeOpts{
+					Namespace: metricNamespace,
+					Name:      backupTotal,
+					Help:      "Current number of existent backups",
+				},
+			),
 			backupAttemptTotal: prometheus.NewCounterVec(
 				prometheus.CounterOpts{
 					Namespace: metricNamespace,
@@ -130,6 +139,13 @@ func NewServerMetrics() *ServerMetrics {
 				},
 				[]string{scheduleLabel},
 			),
+			restoreTotal: prometheus.NewGauge(
+				prometheus.GaugeOpts{
+					Namespace: metricNamespace,
+					Name:      restoreTotal,
+					Help:      "Current number of existent restores",
+				},
+			),
 			restoreAttemptTotal: prometheus.NewCounterVec(
 				prometheus.CounterOpts{
 					Namespace: metricNamespace,
@@ -247,6 +263,13 @@ func (m *ServerMetrics) SetBackupTarballSizeBytesGauge(backupSchedule string, si
 	}
 }
 
+// SetBackupTotal records the current number of existent backups.
+func (m *ServerMetrics) SetBackupTotal(numberOfBackups int64) {
+	if g, ok := m.metrics[backupTotal].(prometheus.Gauge); ok {
+		g.Set(float64(numberOfBackups))
+	}
+}
+
 // RegisterBackupAttempt records an backup attempt.
 func (m *ServerMetrics) RegisterBackupAttempt(backupSchedule string) {
 	if c, ok := m.metrics[backupAttemptTotal].(*prometheus.CounterVec); ok {
@@ -302,6 +325,13 @@ func toSeconds(d time.Duration) float64 {
 	return float64(d / time.Second)
 }
 
+// SetRestoreTotal records the current number of existent restores.
+func (m *ServerMetrics) SetRestoreTotal(numberOfRestores int64) {
+	if g, ok := m.metrics[restoreTotal].(prometheus.Gauge); ok {
+		g.Set(float64(numberOfRestores))
+	}
+}
+
 // RegisterRestoreAttempt records an attempt to restore a backup.
 func (m *ServerMetrics) RegisterRestoreAttempt(backupSchedule string) {
 	if c, ok := m.metrics[restoreAttemptTotal].(*prometheus.CounterVec); ok {