Expose metadata about the servers via GET /v2/

For an OpenStack Registry API 2.0 server:

Get Metadata About the Server
To discover certain metadata about a server, use the following call:

GET /v2
Request body is ignored.

Response will be a 200 OK, with the body containing a JSON-encoded mapping of metadata about the registry server:

{
 ‘_type’: ‘images.registry’,
 ‘image_id_scope’: <IMAGE_ID_SCOPE>
}

<IMAGE_ID_SCOPE> is a string representing whether the image’s managed by this registry endpoint have identifiers that are guaranteed to be unique within the domain, or globally. The two possible string values are domain and global, respectively.

For an OpenStack Streaming API 2.0 server:

Get Metadata About the Server
To discover metadata about a server, use the following call:

GET /v2

Request body is ignored.

Response will be a 200 OK, with the body containing a JSON-encoded mapping of metadata about the image streaming server:

{
 ‘_type’: ‘images.streaming’,
 ‘registries’: [
   {‘read_only’: False,
     ‘uri’: 'https://images1.example.com/v2/’},
   {‘read_only’: True,
     ‘uri’: 'https://images2.example.com/v2/’},
 ]
}