multiple baseURL's

[petersilva]

multiple centres have expressed the desire to not only replace the baseURL on download, but add to it. the most obvious way to do that is to allow the baseURL
to be a JSON array, as well as a singular value. On the one hand, centres want DCPC''s to retain the responsibility, particularly in large datasets, for distribution, and in such cases, may elect not to re-write the baseURL at all. In other cases, to illustrate that there are multiple sources available, one would want to add the baseURL to the others in the list, so as not to monopolize distribution to downstream clients.

[petersilva]

concretely, in the message payload, rather than:

baseURL: "https://hpfx.../"
one could see:

baseURL: [ "https://hpfx.../", "https://svr2...", "sftp://svr3..." ]

@davidpodeur does this look helpful?

[davidpodeur]

This makes sense to me.
However, we loose the "original" baseURL.
Or by convention we can say it should be the first item in the baseURL list.