Re: Intermediate abstraction of system service configuration

[Carlo Zancanaro]

On Tue, Feb 06 2024, Dale Mellor wrote:
>    Agree that it would have repercussions throughout the package
> ecosystem.  I would have thought that it would make things easier.  You
> could argue that you don't benefit from the Guile syntax checker, but
> at the end of the day you don't find out you've made a mistake until
> you try to run `guix system reconfigure` anyway.

It might make things "easier" in one sense, but loosening the
constraints on one thing often makes some other part harder. In
particular, because of service extensions you can't rely on the whole
configuration being written in the same place, so we would need some
sort of merging logic for free-form configurations.

This merging logic would have to be service specific, but would
presumably need to perform its own shape checking (for good error
messages, if nothing else). Presumably this would require some sort of
type definitions, similar to what our current configuration system
requires (maybe with less boilerplate).

I'm sure it's possible to write a system that uses these things, and
there has been some idea of doing this in the past for nginx
specifically[1], but I'm not yet convinced it would actually be easier
across the board. Having used Nix (which has more free-form
configuration), I'm not sure that it's better than what Guix has.

I'm happy to be convinced, though, if you'd like to put together an
implementation. Maybe you could start with a single service (nginx) and
see how it comes together. I'm not a committer, so convincing me doesn't
get things into Guix, but presumably if you can convince me you can
convince a committer as well.

Carlo

[1]: https://issues.guix.gnu.org/37388