[HDDS-517] Implement HeadObject REST endpoint

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.3.0
• Labels: newbie
• Target Version/s: 0.3.0
• Assignee: LiXin Ge
• Reporter: Marton Elek
• Created: 20/Sep/18 07:27
• Updated: 11/Oct/18 10:59
• Resolved: 10/Oct/18 13:49

Description

The HEAD operation retrieves metadata from an object without returning the object itself. This operation is useful if you are interested only in an object's metadata. To use HEAD, you must have READ access to the object.

Steps:
1. Look up the volume
2. Read the key and return to the user.

The AWS reference is here:

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

We have a simple version of this call in HDDS-444 but without Range support.