Alerting: Fix panics when attempting to create an Alertmanager after failing (#94023)

pkg/services/ngalert/metrics/alertmanager.go

@@ -20,7 +20,7 @@ func NewAlertmanagerMetrics(r prometheus.Registerer, l log.Logger) *Alertmanager
 	other := prometheus.WrapRegistererWithPrefix(fmt.Sprintf("%s_%s_", Namespace, Subsystem), r)
 	return &Alertmanager{
 		Registerer:                r,
-		Alerts:                    metrics.NewAlerts(other),
+		Alerts:                    metrics.NewAlerts(other, l),
 		AlertmanagerConfigMetrics: NewAlertmanagerConfigMetrics(r, l),
 	}
 }

pkg/services/ngalert/notifier/alertmanager.go

@@ -135,7 +135,7 @@ func NewAlertmanager(ctx context.Context, orgID int64, cfg *setting.Cfg, store A
 	}
 
 	l := log.New("ngalert.notifier.alertmanager", "org", orgID)
-	gam, err := alertingNotify.NewGrafanaAlertmanager("orgID", orgID, amcfg, peer, l, alertingNotify.NewGrafanaAlertmanagerMetrics(m.Registerer))
+	gam, err := alertingNotify.NewGrafanaAlertmanager("orgID", orgID, amcfg, peer, l, alertingNotify.NewGrafanaAlertmanagerMetrics(m.Registerer, l))
 	if err != nil {
 		return nil, err
 	}