Another GMS WD

[Mark Taylor]

Hi Brian,

a few comments on WD-GMS-1.0-20190329 as requested:

On changing the IVOID scheme from ivo to gms:
   As I understand it, it's not an IVOID if it doesn't use the "ivo" scheme.
   IVOID 2.0 section 2.3.1 says: "The <scheme> part of IVOIDs is ivo.".

   I think(?) that you should abandon the idea of syntactically signalling
   that an IVOID is a Group Identifier.  It's not necessary to do that
   anyway, that's properly signalled by context: an IVOID can be
   treated as a Group Identifier if a capability of its resource has
   standard_id="ivo://ivoa.net/std/gms#search-1.0" (er, or something
   like that).

   Note that the examples in section 4.2 still use the ivo scheme
   in any case - at least usage has to be consistent.

Section 3.2 item 3:
   The IVOID standard seems to use the term "resource key" rather 
   than "path" for this part of the identifier (IVOID 2.0 section 2.3.3).
   I can't remember if there's an important reason for that, but it
   might be a good idea to follow the IVOID rather than URI terminology.

Section 4.1: "(ending with a newline character)": 
   I suggest (being mindful of Goldfarb's First Law of Text Processing) 
   to be explicit here about what's meant by "a newline character".
   I seem to remember that text/plain is supposed always to use CRLF; 
   I can't now find a reference for that, but CRLF is the line end 
   sequence used by RFC822 and HTTP, so it would probably make a 
   good choice.

Section 4.1: 
   The terms "user" and "principal" are still used in several places, 
   I think the intention was to change these to "identity" and 
   "identityType" passim.

Section 4.2:
   "This resolves ... to host http://server.example.com/groupService/search"
   - should probably say "to URL" not "to host".

Examples (sections 3.2, 4.2):
   In the examples it might be a good idea to resolve to (e.g.)
   https://example.com/... rather than http://example.com/...,
   given that real-life use of this protocol will presumably be
   taking security issues seriously.

References:
   A few of the references in the bibliography point at out of date
   document versions; unless there's some reason the older versions
   are preferred, you could update Datalink (to REC), DALI (to v1.1)
   and SSO (to v2.0).

Apart from these, I think it looks basically comprehensible and
well designed.

Mark

On Mon, 1 Apr 2019, Brian Major wrote:

> Hi Grid,
> 
> A second Group Membership Service (GMS) working draft is available:
>     http://www.ivoa.net/documents/GMS/20190329/WD-GMS-1.0-20190329.pdf
> 
> Please have a look and provide your feedback through email or on this page:
>     https://wiki.ivoa.net/twiki/bin/view/IVOA/GroupMembershipService
> 
> From the 'what has changed' section in the document:
>     - Changed GMS IVOID to be in the format gms://authority/path?group
>     - Changed names of params user and principal to identity and
> identityType
>     - Corrected API definition to always return 200 on success
>     - REST API now described in a table
> 
> We'll review and discuss the draft in Paris but it would be good if
> feedback could be received ahead of that meeting.
> 
> Cheers,
> Brian
> 

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/