Support for GCS emulator

[o0neup]

Hi folks!

I imagine it might be quite common to use some object storage emulators wrapped in testcontainers (e.g https://github.com/fsouza/fake-gcs-server for GCS). Is there a way to point obstore to the emulator running in a container?
The google's library has a way of passing the base API endpoint to the client (either via the env variable or explicitly), and perhaps there is or could be a way to do similar things with obstore?

for reference, fake-gcs-server does something like this: https://github.com/fsouza/fake-gcs-server/blob/main/examples/python/python.py (using the google's lib)

[kylebarron]

Obstore has been tested with minio and moto for S3, but I wasn't aware of an emulator for Google Cloud Storage.

It looks like this is supported (by the upstream Rust library that obstore uses) as long as you use a fork of fake-gcs-server that supports the GCS XML API: apache/arrow-rs#5263 (comment)

[o0neup]

@kylebarron thank you for the swift reply!