Persistent TAP uploads

[Markus Demleitner]

Hi Mark,

On Wed, Oct 16, 2024 at 11:56:55PM +0200, Mark Taylor wrote:
> On Mon, 14 Oct 2024, Markus Demleitner via dal wrote:
> I *probably* won't implement any client code before I see you next,
> but just in case I get bored on a train: what about capability
> discoverability?
>
> This almost answers itself: a HEAD request to tap-url/user_tables
> returns:
>
>    404: unsupported
>    403: supported (but you're not authenticated)
>    200: supported (and you are authenticated)

I can't say I like it *too* much, but if we specify it like that, I
think that's more or less safe.

> But I don't see a natural way for an unauthenticated user to find out
> if unauthenticated persistent uploads are permitted.  However the idea
> of an unauthenticated persistent upload is a bit wacky.

Yeah, perhaps it *is* a bit wacky, but I suspect it might work out
reasonably well, so at least offering it as something people *might*
want to implement sounds like a worthwhile effort.

> Maybe this should just be handled by TAPRegExt - but perhaps a bit
> harder to prototype (taplint might give you a hard time?).

I think the *right* way to do this would be via something like the
DALIInterface type I've proposed with caproles:

https://ivoa.net/documents/caproles/20190315/NOTE-caproles-1.0-20190315.html#tth_sEc3.1

Then, the basic declaration would be

  <interface xsi:type="vs:DALIInterface">
    <accessURL>http://example.edu/tap</accessURL>
    <endpoint>sync</endpoint>
    [...]
    <endpoint>user_tables</endpoint>
  </interface>

At some point (that I cannot find any more) we had discussed adding a
facility to attach RDF-like triples to DALIInterface, and with that
the availability of anonymous persistent uploads would be in
something like

  <option property="ivo://ivoa.net/std/tapregext#anonoymous-persistent-uploads"/>

(or use a vocabulary rather than the Stdregext record to list the
available properties)...

(or, with a bow to the recent discussion over on the semantics list,
perhaps

  <option property="[...]anonoymous-persistent-uploads" value="True"/>).

Ok:  We don't have DALIInterface, but since IMHO we'll need that
anyway one day, we could use this as an excuse to start designing it
in earnest.  VODataService is going to go into WD soon-ish anyway
(for productType)...

Thanks,

          Markus