Fix problem where database was required during code initialization

alert.update_alert_plugins() is executed when the module is loaded.
During tests the module is loaded before the test database is created
causing problems. I've changed it to the intented affect of refreshing
on View initialisation

cabot/cabotapp/tests/tests_basic.py

@@ -8,12 +8,14 @@ from datetime import timedelta, date
 import os
 import requests
 from cabot.cabotapp.graphite import parse_metric
+from cabot.cabotapp.alert import update_alert_plugins
 from cabot.cabotapp.models import (
     GraphiteStatusCheck, JenkinsStatusCheck,
     HttpStatusCheck, ICMPStatusCheck, Service, Instance,
     StatusCheckResult, minimize_targets)
 from cabot.cabotapp.calendar import get_events
 from cabot.cabotapp.views import StatusCheckReportForm
+from django.conf import settings
 from django.contrib.auth.models import Permission
 from django.contrib.auth.models import User
 from django.core import mail
@@ -932,6 +934,16 @@ class TestAlerts(LocalTestCase):
         self.assertEqual(fake_send_alert.call_count, 1)
         fake_send_alert.assert_called_with(self.service, duty_officers=[])
 
+    def test_update_plugins(self):
+        # Test that disabling a plugin is detected by update_alert_plugins
+        plugins = update_alert_plugins()
+        plugin_count = len(plugins)
+        new_apps = [s for s in settings.INSTALLED_APPS if s not in ['cabot_alert_hipchat']]
+
+        with self.settings(INSTALLED_APPS=new_apps):
+            plugins = update_alert_plugins()
+            self.assertEqual(len(plugins), plugin_count - 1)
+
 
 class TestMinimizeTargets(LocalTestCase):
     def test_null(self):

cabot/cabotapp/views.py

@@ -704,7 +704,9 @@ class ServiceCreateView(LoginRequiredMixin, CreateView):
     model = Service
     form_class = ServiceForm
 
-    alert.update_alert_plugins()
+    def __init__(self, *args, **kwargs):
+        alert.update_alert_plugins()
+        super(ServiceCreateView, self).__init__(*args, **kwargs)
 
     def get_success_url(self):
         return reverse('service', kwargs={'pk': self.object.id})