500 instead of 204 when no report is available for too long

src/Handler/Health.hs

@@ -12,7 +12,13 @@ getHealthR :: Handler TypedContent
 getHealthR = do
   healthReport' <- liftIO . readTVarIO =<< getsYesod appHealthReport
   case healthReport' of
-    Nothing -> sendResponseStatus noContent204 ()
+    Nothing -> do
+      interval <- getsYesod $ round . (* 1e6) . toRational . view _appHealthCheckInterval
+      reportStore <- getsYesod appHealthReport
+      waitResult <- threadDelay interval `race` atomically (readTVar reportStore >>= guard . is _Just)
+      case waitResult of
+        Left () -> fail "System is not generating HealthReports"
+        Right _ -> redirect HealthR
     Just (lastUpdated, healthReport) -> do
       rContent <- selectRep $ do
         provideRep $