Re: Composing service definitions (and maybe fmt)

[ludo@gnu.org (Ludovic Courtès)]

"Thompson, David" <dthompson2@worcester.edu> skribis:

> On Wed, Jan 20, 2016 at 5:13 PM, Ludovic Courtès <ludo@gnu.org> wrote:
>
>> To me, the question is more about choosing between writing configuration
>> file bindings and exposing upstream’s configuration file syntax, as was
>> discussed when Andy posted the Dovecot service.  (To which I don’t have
>> a better answer than: let’s see on a case-by-case basis.)
>
> How about this:
>
> Procedures that return services should accept file-like objects when
> configuration files are needed.  When it makes sense (like with
> elogind, dovecot, etc.), we can provide special procedures that take a
> Scheme data structure and "compile" that to a file-like object in the
> service's native configuration language.  This way, we allow ourselves
> to have the high-level Scheme configuration APIs we like while also
> allowing the use of "raw" configuration files in situations where it
> is unavoidable or the path of least resistance.

I like it!  When we provide Scheme data structures, we necessarily have
a ‘foo-configuration->file’ procedure anyway, so it’s just a matter of
exposing it.

Ludo’.