Enable rate limiting (#25642)

* Enable rate limiting

* higher limit specifically when running tests

middleware/rate-limit.js

@@ -13,7 +13,7 @@ export default rateLimit({
   // by the current number of instances.
   // We have see DDoS attempts against prod that hits the `/` endpoint
   // (and not following the redirect to `/en`) at roughly 200k per minute.
-  max: 100,
+  max: process.env.NODE_ENV === 'test' ? 1000 : 100,
 
   // Return rate limit info in the `RateLimit-*` headers
   standardHeaders: true,
@@ -23,10 +23,6 @@ export default rateLimit({
   handler: (request, response, next, options) => {
     const tags = [`url:${request.url}`, `ip:${request.ip}`]
     statsd.increment('middleware.rate_limit', 1, tags)
-    // NOTE! At the time of writing, the actual rate limiting is disabled!
-    // At least we can start recording how often this happens in Datadog.
-    // The following line is commented out and replaced with `next()`
-    // response.status(options.statusCode).send(options.message)
-    next()
+    response.status(options.statusCode).send(options.message)
   },
 })