[Question]: Source code of packages hosted on ipv6 only website

[EruEri]

I have a question, In general, is it an issue if the source code of a package is hosted on a website on reachable via ipv6 ?

Thanks for your time.

[raphael-proust]

We (opam-repo maintainers) discussed this during the maintenance meeting. We think it would be ok because opam provides some tools for mirroring and such.

Don't hesitate to open a PR with your package and there can be a more thorough discussion there with more people involved.

[EruEri]

Ok, thanks you for your reply and time.

[avsm]

This will cause quite a bit of pain to users of opam-repo who are stuck on IPv4-only infra (such as GitHub actions actions/runner-images#668). I think, sadly, that the primary URL for a package being ipv6-only would be problematic in opam-repo in practise unless there's a way to make the opam client fallback on failure to an alternative source automatically. Otherwise the opam install would just fail.

[hannesm]

My perspective (that I shared in the opam-repository meeting):

• the opam.ocaml.org machine(s) have IPv6 addresses assigned, so we assume they will be able to download and cache the archives,
• there's a zoo of CI machines and docker images which use this git repository as opam source. here, if you encounter such a docker image and have control, please add to ~/.opam/config the line archive-mirrors: [ "https://opam.ocaml.org/cache" ] -- and now magically, the opam.ocaml.org host will be used for tarballs (so, ipv4/ipv6 will be fine, and the cache will be fine).

If you're aware of any other systems that are not able to use the archive-mirrors, please discuss. But keep in mind that legacy IP is going away and you need a lot of privileges to host your stuff on IPv4 systems -- plus we have all the bits and pieces in place to smoothly transition to IPv6 without an issue. If there are any issues, please discuss on the respective issue tracker.

[hannesm]

Unfortunately, it is not clear to me what the impact of the issue ocaml/infrastructure#42 is, and whether the infrastructure team monitors and provides IPv6 service.