Re: [PATCH] services: Make dovecot and cups configuration abstractions available

[ludo@gnu.org (Ludovic Courtès)]

Hi Julien,

Julien Lepiller <julien@lepiller.eu> skribis:

> since I will probably use it in openvpn-service and maybe in
> nginx-service, I moved the definitions of the documentation that was
> duplicated in cups and dovecot to services.scm. Is it the best place
> for it?

Thanks for looking into it!

I would suggest moving it to a new (gnu services configuration) module
instead, if that’s fine with you.

Could you send an updated patch?

BTW, I just checked and there’s at least one subtle difference between
cups.scm and mail.scm: ‘define-configuration’ in cups.scm defines the
constructor as a macro that calls ‘validate-configuration’:

               (define-syntax-rule (stem arg (... ...))
                 (let ((conf (#,(id #'stem #'% #'stem) arg (... ...))))
                   (validate-configuration conf
                                           #,(id #'stem #'stem #'-fields))
                   conf))

The version in mail.scm does not do that, but I think we want to
preserve it (and your patch does seem to preserve that already).

Probably the are serializers that can be factorized as well.

> From 9acc9456f4e61506105bc109298aedb66e31efd0 Mon Sep 17 00:00:00 2001
> From: Julien Lepiller <julien@lepiller.eu>
> Date: Sun, 20 Nov 2016 17:56:08 +0100
> Subject: [PATCH] services: Make dovecot and cups configuration abstractions
>  available.
>
> * gnu/services.scm: Add configuration-field, configuration-missing-field,
> configuration-field-error, serialize-confgiuration, define-configuration,
> validate-configuration, validate-configuration and generate-documetation.
> * gnu/services/cups.scm: Use it.
> * gnu/services/mail.scm: Use it.

Please take some time to see the ChangeLog convention for this.

> + ; (define (str x) (object->string x))
> + ; (define (generate configuration-name)
> + ;   (match (assq-ref documentation configuration-name)
> + ;     ((fields . sub-documentation)
> + ;      `((para "Available " (code ,(str configuration-name)) " fields are:")
> + ;        ,@(map
> + ;           (lambda (f)
> + ;             (let ((field-name (configuration-field-name f))

Why comment things out?  Could it be moved to (gnu services
configuration) as well?

Thanks!

Ludo’.