fetch fullsnapshotinterval from the etcd spec fullsnapshotschedule

go.mod

@@ -104,6 +104,7 @@ require (
 	github.com/prometheus/client_model v0.4.0 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.10.1 // indirect
+	github.com/robfig/cron v1.2.0 // indirect
 	github.com/robfig/cron/v3 v3.0.1 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/sirupsen/logrus v1.9.0 // indirect

go.sum

@@ -438,6 +438,8 @@ github.com/prometheus/procfs v0.10.1 h1:kYK1Va/YMlutzCGazswoHKo//tZVlFpKYh+Pymzi
 github.com/prometheus/procfs v0.10.1/go.mod h1:nwNm2aOCAYw8uTR/9bWRREkZFxAUcWzPHWJq+XBB/FM=
 github.com/rakyll/gotest v0.0.6 h1:hBTqkO3jiuwYW/M9gL4bu0oTYcm8J6knQAAPUsJsz1I=
 github.com/rakyll/gotest v0.0.6/go.mod h1:SkoesdNCWmiD4R2dljIUcfSnNdVZ12y8qK4ojDkc2Sc=
+github.com/robfig/cron v1.2.0 h1:ZjScXvvxeQ63Dbyxy76Fj3AT3Ut0aKsyd2/tl3DTMuQ=
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
 github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
 github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=

internal/health/condition/check_backup_ready.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	druidv1alpha1 "github.com/gardener/etcd-druid/api/v1alpha1"
+	"github.com/gardener/etcd-druid/internal/utils"
 	coordinationv1 "k8s.io/api/coordination/v1"
 
 	"k8s.io/apimachinery/pkg/types"
@@ -54,19 +55,26 @@ func (f *fullSnapshotBackupReadyCheck) Check(ctx context.Context, etcd druidv1al
 
 	//Fetch snapshot leases
 	var (
-		fullSnapErr   error
-		fullSnapLease = &coordinationv1.Lease{}
+		fullSnapErr          error
+		fullSnapLease        = &coordinationv1.Lease{}
+		fullSnapshotInterval = 24 * time.Hour
+		err                  error
 	)
 	fullSnapErr = f.cl.Get(ctx, types.NamespacedName{Name: getFullSnapLeaseName(&etcd), Namespace: etcd.ObjectMeta.Namespace}, fullSnapLease)
 	fullLeaseRenewTime := fullSnapLease.Spec.RenewTime
 	fullLeaseCreationTime := fullSnapLease.ObjectMeta.CreationTimestamp
 
+	if etcd.Spec.Backup.FullSnapshotSchedule != nil {
+		if fullSnapshotInterval, err = utils.ComputeScheduleInterval(*etcd.Spec.Backup.FullSnapshotSchedule); err != nil {
+			return result
+		}
+	}
 	//Set status to Unknown if errors in fetching full snapshot lease
 	if fullSnapErr != nil {
 		return result
 	}
 	if fullLeaseRenewTime == nil {
-		if time.Since(fullLeaseCreationTime.Time) < 24*time.Hour {
+		if time.Since(fullLeaseCreationTime.Time) < fullSnapshotInterval {
 			return result
 		} else {
 			result.status = druidv1alpha1.ConditionFalse
@@ -75,7 +83,7 @@ func (f *fullSnapshotBackupReadyCheck) Check(ctx context.Context, etcd druidv1al
 			return result
 		}
 	} else {
-		if time.Since(fullLeaseRenewTime.Time) < 24*time.Hour {
+		if time.Since(fullLeaseRenewTime.Time) < fullSnapshotInterval {
 			result.status = druidv1alpha1.ConditionTrue
 			result.reason = SnapshotUploadedOnSchedule
 			result.message = fmt.Sprintf("Full snapshot uploaded successfully %v ago", time.Since(fullLeaseRenewTime.Time))

internal/utils/miscellaneous.go

@@ -8,7 +8,9 @@ import (
 	"fmt"
 	"maps"
 	"strings"
+	"time"
 
+	"github.com/robfig/cron"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -76,3 +78,19 @@ func IfConditionOr[T any](condition bool, trueVal, falseVal T) T {
 func PointerOf[T any](val T) *T {
 	return &val
 }
+
+// ComputeScheduleInterval computes the interval between two activations for the given cron schedule.
+// Assumes that every cron activation is at equal intervals apart, based on cron schedules such as
+// "once every X hours", "once every Y days", "at 1:00pm on every Tuesday", etc.
+// TODO: write a new function to accurately compute the previous activation time from the cron schedule
+// in order to compute when the previous activation of the cron schedule was supposed to have occurred,
+// instead of relying on the assumption that all the cron activations are evenly spaced.
+func ComputeScheduleInterval(cronSchedule string) (time.Duration, error) {
+	schedule, err := cron.ParseStandard(cronSchedule)
+	if err != nil {
+		return 0, err
+	}
+	nextScheduledTime := schedule.Next(time.Now())
+	nextNextScheduledTime := schedule.Next(nextScheduledTime)
+	return nextNextScheduledTime.Sub(nextScheduledTime), nil
+}