Occasional 400s from fetching features

[Abdullah0sama]

Describe the feature request

Improve the logging the repository fetch function to emit a more informative than the current one
Error: Unleash Repository error: Response was not statusCode 2XX, but was 400

Background

Starting from last week, we have been noticing this error log in some cases where most of the the responses are actually 304 but occasionally we see 400s (without actually changing anything), which is strange.
So debugging such case has been difficult without having a proper log in place to know the root case.

Solution suggestions

We could somehow enable access to the request or response in the error to improve logs

[gastonfournier]

Hi @Abdullah0sama are you using Unleash cloud? Also, did you subscribe to the event listener for events? It may provide some more details. But also if you'd like more details in the error log feel free to open a PR as well, we'll review it.

[Abdullah0sama]

We were using gitlab's unleash, and regarding the events unfortunately the events weren't exposing more info than the logs.
For now the errors stopped, it started suddenly for a while and stopped suddenly so my explanation that gitlab had a release that was incompatible with the client and then rolled back.

[Abdullah0sama]

I'll close the issue and if it happened again I'll create a PR. Thanks for your help.

[gastonfournier]

Thanks for sharing the details @Abdullah0sama! I think the better error log is still worthwhile, so if you want to contribute, feel free to do so!

wrt gitlab feature flags, they're currently using a ~3 years old specification of Unleash server, but not running Unleash server. It's their own implementation and is not compatible with https://github.com/Unleash/unleash-edge which is the evolution of https://github.com/Unleash/unleash-proxy (now in maintenance mode).