Fix ping handler to return "not found" in 404 body

hc/api/tests/test_ping.py

@@ -76,6 +76,7 @@ class PingTestCase(BaseTestCase):
     def test_it_handles_missing_check(self):
         r = self.client.get("/ping/07c2f548-9850-4b27-af5d-6c9dc157ec02/")
         self.assertEqual(r.status_code, 404)
+        self.assertEqual(r.content.decode(), "not found")
 
     def test_it_handles_120_char_ua(self):
         ua = (

hc/api/tests/test_ping_by_slug.py

@@ -35,6 +35,7 @@ class PingBySlugTestCase(BaseTestCase):
     def test_it_handles_missing_check(self):
         r = self.client.get(f"/ping/{self.project.ping_key}/bar")
         self.assertEqual(r.status_code, 404)
+        self.assertEqual(r.content.decode(), "not found")
 
     def test_it_never_caches(self):
         r = self.client.get(self.url)

hc/api/views.py

@@ -33,7 +33,10 @@ class BadChannelException(Exception):
 @never_cache
 def ping(request, code, check=None, action="success", exitstatus=None):
     if check is None:
-        check = get_object_or_404(Check, code=code)
+        try:
+            check = Check.objects.get(code=code)
+        except Check.DoesNotExist:
+            return HttpResponseNotFound("not found")
 
     if exitstatus is not None and exitstatus > 255:
         return HttpResponseBadRequest("invalid url format")
@@ -62,7 +65,9 @@ def ping(request, code, check=None, action="success", exitstatus=None):
 @csrf_exempt
 def ping_by_slug(request, ping_key, slug, action="success", exitstatus=None):
     try:
-        check = get_object_or_404(Check, slug=slug, project__ping_key=ping_key)
+        check = Check.objects.get(slug=slug, project__ping_key=ping_key)
+    except Check.DoesNotExist:
+        return HttpResponseNotFound("not found")
     except Check.MultipleObjectsReturned:
         return HttpResponse("ambiguous slug", status=409)