Adjust GetObject satellite endpoint (object retention)

[amwolff]

Goal

This issue is to make meaningful progress on Object Lock implementation within core and edge services. Specifically, to support immutable backups in backup software products like Veeam.

What needs to be done? • Acceptance Criteria

Modify the corresponding to GetObject endpoint on the satellite (the endpoint might be named differently) to respond with the following:

• the Object Lock mode that's currently in place for this object
• the date and time when this object's Object Lock will expire
• Legal Hold and governance mode (retention mode) is out of scope at this moment

Summary

Implementation reference.

Depends on…

• Decide where and make it possible to store per-object metadata for Object Lock #400

Links

• https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html
• an easy-to-read and insightful introduction to Object Lock: Using S3 Object Lock

[storj-gerrit]

Change satellite/{metabase/metainfo}: allow uploading objects with retention mentions this issue.