Add n_pings field to Check model. This holds a continually updated count of api_ping entries for each check.

hc/api/management/commands/fillnpings.py

@@ -0,0 +1,13 @@
+from django.core.management.base import BaseCommand
+from hc.api.models import Check, Ping
+
+
+class Command(BaseCommand):
+    help = 'Fill check.n_pings field'
+
+    def handle(self, *args, **options):
+        for check in Check.objects.all():
+            check.n_pings = Ping.objects.filter(owner=check).count()
+            check.save()
+
+        print("Done.")

hc/api/migrations/0020_check_n_pings.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9 on 2015-12-30 12:06
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0019_check_tags'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='check',
+            name='n_pings',
+            field=models.IntegerField(default=0),
+        ),
+    ]

hc/api/models.py

@@ -48,6 +48,7 @@ class Check(models.Model):
     created = models.DateTimeField(auto_now_add=True)
     timeout = models.DurationField(default=DEFAULT_TIMEOUT)
     grace = models.DurationField(default=DEFAULT_GRACE)
+    n_pings = models.IntegerField(default=0)
     last_ping = models.DateTimeField(null=True, blank=True)
     alert_after = models.DateTimeField(null=True, blank=True, editable=False)
     status = models.CharField(max_length=6, choices=STATUSES, default="new")

hc/api/views.py

@@ -1,6 +1,7 @@
 import json
 
 from django.contrib.humanize.templatetags.humanize import naturaltime
+from django.db.models import F
 from django.http import HttpResponse, HttpResponseBadRequest
 from django.utils import timezone
 from django.views.decorators.csrf import csrf_exempt
@@ -16,6 +17,7 @@ def ping(request, code):
     except Check.DoesNotExist:
         return HttpResponseBadRequest()
 
+    check.n_pings = F("n_pings") + 1
     check.last_ping = timezone.now()
     if check.status == "new":
         check.status = "up"
@@ -52,6 +54,7 @@ def handle_email(request):
             except Check.DoesNotExist:
                 continue
 
+            check.n_pings = F("n_pings") + 1
             check.last_ping = timezone.now()
             if check.status == "new":
                 check.status = "up"