Google App Engine standard doesn't compress my Next.js/Express app

Question

I'm trying to figure out what to do to make Google App Engine (standard version) apply compression to the output of my Next.js/Node.js/Express application.

As far as I've gathered, the problem is that

1) Google's load balancer removes all meta tags indicating that the client supports compression from the request, and thus app.use(compression()) in server.js won't do anything. I've tried to force compression using a {filter: shouldCompress} function, but doesn't seem to matter since Google's front end still returns an uncompressed result. (Locally compression works fine.)

2) How and when Google's load balancer chooses to apply compression is a mystery to me. (And particularly, why not to my silly but large application/javascsript content :))

Here's what they say in the docs:

If the client sends HTTP headers with the original request indicating that the client can accept compressed (gzipped) content, App Engine compresses the handler response data automatically and attaches the appropriate response headers. It uses both the Accept-Encoding and User-Agent request headers to determine if the client can reliably receive compressed responses. How Requests are Handled: Response Compression

So there's that. I'd love to use App Engine for this project but when index.js is 700KB instead of a compressed 200KB, it's kind of a showstopper.

Answer 1

As per the Request Headers and Responses documentation for Node.js, the Accept-Encoding header is removed from the request for security purpose.

Note: Entity headers (headers relating to the request body) are not sanitized or checked, so applications should not rely on them. In particular, the Content- MD5 request header is sent unmodified to the application, so may not match the MD5 hash of the content. Also, the Content-Encoding request header is not checked by the server, so if the client sends a gzipped request body, it will be sent in compressed form to the application.

Also note the response on Google Group which states:

Today, we are not passing through the Accept-Encoding header, so it is not possible for your middleware to decide that it should compress.

We will roll out a fix for this in the new few weeks.