Add 'asta_confirmed_total' metric

shiftregister/metrics/views.py

@@ -16,6 +16,10 @@ def metrics(request):
             (
                 f"shiftregister_{name} {value}"
                 for name, value in (
+                    (
+                        "asta_confirmed_total",
+                        Helper.objects.filter(asta_confirmed=True).count(),
+                    ),
                     (
                         "fallback_shifts",
                         Event.objects.filter(