Sorry for the late response, for some reason your mail didn't end
up in my inbox.  A reminder for what my goal is: I am attempting
to serve substitutes via a P2P system.  Ludovic has a patch
for substitutes over IPFS, myself I'm planning to write a patch
for substitutes over GNUnet.  This patch aims to define a
simple ‘hook’ into ‘guix publish’ for adding the IPFS or GNUnet
URI.

On Mon, 2021-02-01 at 23:22 +0100, Jonathan Brielmaier wrote:
> 
> On 31.01.21 12:11, Maxime Devos wrote:
> > [...]
> > I've defined a ‘narinfo-hook’, which allows adding extra
> > key value pairs to the generated narinfos.  [...]
> I didn't looked really into the code, but would this also allow hooks
> like baking the nar-file and write it into the cache? Or is it only for
> the narinfos?

This patch is only for the generation of the narinfos.

(I would like to eventually write a hook that publishes
the store item via GNUnet and embeds the URI in the narinfo,
but there isn't yet a corresponding hook mechanism on
the substituter side.)

That said, other hook types could be defined with additional
patches, though I don't know what use that would serve.

Greetings,
Maxime.