[HDDS-10640] Support x-amz-mp-parts-count for MPU key

• Type: Sub-task
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: S3, s3gateway
• Labels: GoodForNewContributors newbie
• Assignee: Unassigned
• Reporter: Ivan Andika
• Created: 04/Apr/24 03:04
• Updated: 05/Apr/24 05:39

Description

Description: The count of parts this object has. This value is only returned if you specify partNumber in your request and the object was uploaded as a multipart upload.

Reference:

https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html

https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html

Possible implementation: Since ETag of MPU key suffix is the number of the parts in the MPU, we can use that instead. If the ETag does not contain the number of MPU part (e.g. legacy MPU key), don't return the response header. 

Should be tested using unit tests and acceptance tests.