Feature Request: Support for GCS `predefinedAcl` query parameter in `put`/`put_async`

[hjed]

Summary

Add support for passing GCS-specific query parameters (specifically predefinedAcl) when uploading objects via put/put_async to Google Cloud Storage.

Motivation

When uploading objects to GCS buckets that use legacy ACLs (not uniform bucket-level access), it's common to need to set the object's access control at upload time. Currently, obstore's put_async only supports the attributes parameter which maps to HTTP headers (Content-Type, Cache-Control, etc.), but doesn't provide a way to pass GCS-specific query parameters like predefinedAcl.

This forces users to make a separate API call after upload to set the ACL, which:

1. Adds latency (extra round-trip)
2. Creates a race condition window where the object exists but isn't publicly accessible
3. Requires using a separate GCS client library (e.g., gcloud-aio-storage) just for ACL management
4. Can cause errors due to timing issues

Current Workaround

from gcloud.aio.storage import Storage

# Upload with obstore
store = GCSStore(bucket=bucket_name)
await store.put_async(path=object_name, file=stream, attributes={"Content-Type": content_type})

# Separate call to set ACL using different library
aio_client = Storage(session=session)
await aio_client.patch_metadata(
    bucket=bucket_name,
    object_name=object_name,
    metadata={},
    params={"predefinedAcl": "publicRead"},
)

Proposed Solution

Add an optional options or gcs_options parameter to put/put_async that allows passing GCS-specific query parameters:

await store.put_async(
    path=object_name,
    file=stream,
    attributes={"Content-Type": content_type},
    # New parameter for GCS/Provider specific options
    options={"predefinedAcl": "publicRead"},
)

Alternatively could be supported in attributes?

GCS API Reference

The predefinedAcl parameter is documented in the GCS JSON API for object insertion:

• Objects: insert - https://cloud.google.com/storage/docs/json_api/v1/objects/insert

  • Query parameter: predefinedAcl (string)
  • Acceptable values: authenticatedRead, bucketOwnerFullControl, bucketOwnerRead, private, projectPrivate, publicRead

• Predefined ACLs overview - https://cloud.google.com/storage/docs/access-control/lists#predefined-acl

[kylebarron]

This library is a wrapper and we don't touch the raw requests here. You'll have to make the feature request in https://github.com/apache/arrow-rs-object-store