Recommendations on test data

[Guido Günther]

Hi,
sometimes it's useful to be able to fetch resources via e.g. http from
the network (e.g. prebuilt vm images for testing libvirt). Are there any
recommendations on how to do this? Often one might rather want the
opposite - restrict network access (as detailed in e.g. 801895) but I
wonder if there's a need for a "needs-network" restrictions and maybe
even a way how to specify the URLs that can be reached?
I didn't find any mention if network access is allowed/forbidden in
DEP-8 either.

I'm pretty sure other packages have similar problems but wasn't able to
find any examples.

Happy about any pointers,
 -- Guido