return 404 if checking an object that doesn't exist (#5842)

hobo/environment/views.py

@@ -3,7 +3,8 @@ import string
 
 from django.conf import settings
 from django.core.urlresolvers import reverse_lazy
-from django.http import HttpResponse
+from django.http import HttpResponse, Http404
+from django.shortcuts import get_object_or_404
 from django.views.generic.base import TemplateView
 from django.views.generic.edit import CreateView, UpdateView, DeleteView
 
@@ -136,12 +137,16 @@ class ServiceDeleteView(DeleteView):
         return None
 
 def operational_check_view(request, service, slug, **kwargs):
-    if service == 'wcs':
-        object = Wcs.objects.get(slug=slug)
-    elif service == 'authentic':
-        object = Authentic.objects.get(slug=slug)
-    elif service == 'passerelle':
-        object = Passerelle.objects.get(slug=slug)
+    klass = {
+            'wcs': Wcs,
+            'authentic': Authentic,
+            'passerelle': Passerelle
+    }.get(service)
+
+    if klass is None:
+        raise Http404
+
+    object = get_object_or_404(klass, slug=slug)
     object.check_operational()
     response = HttpResponse(content_type='application/json')
     json.dump({'operational': object.is_operational()}, response)