How to add object retention while using open/cat/put?

[ketozhang]

I can't tell from the following the kwargs in S3FileSystem open/cat/put (etc?) if there's a way to also add object retention policy.

https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3/client/put_object_retention.html

[martindurant]

I don't believe we have a way to hit that endpoint. It would probably make most sense with in chmod(), which at the moment is only capable of assigning a canned ACL rule to object(s), but I could imagine it being more general purpose. Of course, it would need someone to put in a little work to figure out a friendly API.