On Wed, 17 Jan 2018 18:58:08 -0500
Quiliro Ordonez Baca <quiliro@riseup.net> wrote:

> I am not sure if this has been asked before. But I live in a place where
> there is no network link and I would like users to install different
> softwares there.
> 
> Is it possible to have a machine connect to the net every so often so
> that it updates all available substitutes (or source if substitutes are
> not available)...and then take that machine to an offline site where
> other machines use it to install all packages that users want?
> 

I don't think we don't have anything out-of-the-box that would elegantly
handle a use-case like this.  That being said, you should be able to
hack something together.  I think a good place to start would be the
recent work Ludovic did on 'guix weather', which queries substitute
servers for availability of package substitutes.  You could base
something off that which, instead of simply reporting statistics,
actually builds the derivations: either the source derivation if a
substitute is unavailable, or the package derivation.

Obviously, downloading substitutes and/or source for all
packages could take quite a but of time, so you may instead want to
limit to a manifest of the packages you're interested in.  But that
could get more complicated because a package's source is "useless"
unless you have sources or substitutes of the packages needed to build
it, so you'd need to analyze the dependency tree a bit.

It's an interesting use-case.

Happy Hacking,
`~Eric