Add CLI args for snapshot intervals (#2849)

* Add CLI args for snapshot intervals

Signed-off-by: sed-i <82407168+sed-i@users.noreply.github.com>

* Apply suggestions from code review

Co-authored-by: Simon Pasquier <spasquie@redhat.com>
Signed-off-by: sed-i <82407168+sed-i@users.noreply.github.com>

* use same flag for silences and nflogs intervals

Signed-off-by: sed-i <82407168+sed-i@users.noreply.github.com>

Co-authored-by: Simon Pasquier <spasquie@redhat.com>

cmd/alertmanager/main.go

@@ -190,10 +190,11 @@ func run() int {
 	}
 
 	var (
-		configFile      = kingpin.Flag("config.file", "Alertmanager configuration file name.").Default("alertmanager.yml").String()
-		dataDir         = kingpin.Flag("storage.path", "Base path for data storage.").Default("data/").String()
-		retention       = kingpin.Flag("data.retention", "How long to keep data for.").Default("120h").Duration()
-		alertGCInterval = kingpin.Flag("alerts.gc-interval", "Interval between alert GC.").Default("30m").Duration()
+		configFile          = kingpin.Flag("config.file", "Alertmanager configuration file name.").Default("alertmanager.yml").String()
+		dataDir             = kingpin.Flag("storage.path", "Base path for data storage.").Default("data/").String()
+		retention           = kingpin.Flag("data.retention", "How long to keep data for.").Default("120h").Duration()
+		maintenanceInterval = kingpin.Flag("data.maintenance-interval", "Interval between garbage collection and snapshotting to disk of the silences and the notification logs.").Default("15m").Duration()
+		alertGCInterval     = kingpin.Flag("alerts.gc-interval", "Interval between alert GC.").Default("30m").Duration()
 
 		webConfig      = webflag.AddFlags(kingpin.CommandLine)
 		externalURL    = kingpin.Flag("web.external-url", "The URL under which Alertmanager is externally reachable (for example, if Alertmanager is served via a reverse proxy). Used for generating relative and absolute links back to Alertmanager itself. If the URL has a path portion, it will be used to prefix all HTTP endpoints served by Alertmanager. If omitted, relevant URL components will be derived automatically.").String()
@@ -273,7 +274,7 @@ func run() int {
 	notificationLogOpts := []nflog.Option{
 		nflog.WithRetention(*retention),
 		nflog.WithSnapshot(filepath.Join(*dataDir, "nflog")),
-		nflog.WithMaintenance(15*time.Minute, stopc, wg.Done, nil),
+		nflog.WithMaintenance(*maintenanceInterval, stopc, wg.Done, nil),
 		nflog.WithMetrics(prometheus.DefaultRegisterer),
 		nflog.WithLogger(log.With(logger, "component", "nflog")),
 	}
@@ -310,7 +311,7 @@ func run() int {
 	// Start providers before router potentially sends updates.
 	wg.Add(1)
 	go func() {
-		silences.Maintenance(15*time.Minute, filepath.Join(*dataDir, "silences"), stopc, nil)
+		silences.Maintenance(*maintenanceInterval, filepath.Join(*dataDir, "silences"), stopc, nil)
 		wg.Done()
 	}()