Add InstanceStatusSnapshot to cleanup db task

These are also piling up and should be deleted

cabot/cabotapp/tasks.py

@@ -74,26 +74,36 @@ def clean_db(days_to_retain=7, batch_size=10000):
 
     To loop over undeleted results, spawn new tasks to make sure db connection closed etc
     """
-    from .models import StatusCheckResult, ServiceStatusSnapshot
+    from .models import StatusCheckResult, ServiceStatusSnapshot, InstanceStatusSnapshot
 
     to_discard_results = StatusCheckResult.objects.order_by('time_complete').filter(
         time_complete__lte=timezone.now() - timedelta(days=days_to_retain)
     )
-    to_discard_snapshots = ServiceStatusSnapshot.objects.order_by('time').filter(
+    to_discard_service = ServiceStatusSnapshot.objects.order_by('time').filter(
+        time__lte=timezone.now() - timedelta(days=days_to_retain)
+    )
+    to_discard_instance = InstanceStatusSnapshot.objects.order_by('time').filter(
         time__lte=timezone.now() - timedelta(days=days_to_retain)
     )
 
     result_ids = to_discard_results[:batch_size].values_list('id', flat=True)
-    snapshot_ids = to_discard_snapshots[:batch_size].values_list('id', flat=True)
+    service_snapshot_ids = to_discard_service[:batch_size].values_list('id', flat=True)
+    instance_snapshot_ids = to_discard_instance[:batch_size].values_list('id', flat=True)
 
     result_count = result_ids.count()
-    snapshot_count = snapshot_ids.count()
+    service_snapshot_count = service_snapshot_ids.count()
+    instance_snapshot_count = instance_snapshot_ids.count()
 
     StatusCheckResult.objects.filter(id__in=result_ids).delete()
-    ServiceStatusSnapshot.objects.filter(id__in=snapshot_ids).delete()
+    ServiceStatusSnapshot.objects.filter(id__in=service_snapshot_ids).delete()
+    InstanceStatusSnapshot.objects.filter(id__in=instance_snapshot_ids).delete()
 
     # If we reached the batch size on either we need to re-queue to continue cleaning up.
-    if result_count == batch_size or snapshot_count == batch_size:
+    if (
+            result_count == batch_size or
+            service_snapshot_count == batch_size or
+            instance_snapshot_count == batch_size
+    ):
         clean_db.apply_async(kwargs={
             'days_to_retain': days_to_retain,
             'batch_size': batch_size},