502 Errors for POST requests

[gwil]

@jerome I was looking through a few new threads and some things caught my eye:

@kurt

This error was the result of a failure to read the body from the request. We’re going to try to reproduce the problem. It could be a bug on our end, it might be something specific about how a browser is interacting with our proxy. It’s probably not your app.

My own error is caused by my app seemingly not being able to read the body of the request (via request.text or request.json).

@lewis

When trying this out locally, upload latencies were reasonable in the sub ~100ms range. However, the same service when deployed to Fly results in uploads of over 3 seconds for files that are larger than ~30KB. For smaller files the latencies are within the same ballpark as local dev, which makes this even more puzzling.

This error seems to happen for POST requests where the body is over 30kb in size. Below that, and the POST requests react as they are expected to.