From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: [PATCH] gnu: Add postgresql-service.
Date: Wed, 06 May 2015 22:27:14 +0200
Message-ID: <87k2wlqwnx.fsf@gnu.org>
References: <87y4l53vg6.fsf@fsf.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:60562)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1Yq5ua-0007oE-RQ
	for guix-devel@gnu.org; Wed, 06 May 2015 16:27:21 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1Yq5uX-0005ah-Cx
	for guix-devel@gnu.org; Wed, 06 May 2015 16:27:20 -0400
Received: from fencepost.gnu.org ([2001:4830:134:3::e]:34017)
	by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from <ludo@gnu.org>)
	id 1Yq5uX-0005ad-AQ
	for guix-devel@gnu.org; Wed, 06 May 2015 16:27:17 -0400
In-Reply-To: <87y4l53vg6.fsf@fsf.org> (David Thompson's message of "Sun, 03
	May 2015 22:52:57 -0400")
List-Id: "Development of GNU Guix and the GNU System distribution."
	<guix-devel.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/guix-devel>
List-Post: <mailto:guix-devel@gnu.org>
List-Help: <mailto:guix-devel-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/guix-devel>,
	<mailto:guix-devel-request@gnu.org?subject=subscribe>
Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org
Sender: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org
To: David Thompson <dthompson2@worcester.edu>
Cc: guix-devel@gnu.org

David Thompson <dthompson2@worcester.edu> skribis:

> From 888bb58253ab708f38609aa839e77a46a96bd0df Mon Sep 17 00:00:00 2001
> From: David Thompson <dthompson2@worcester.edu>
> Date: Sun, 3 May 2015 17:02:59 -0400
> Subject: [PATCH] gnu: Add postgresql-service.
>
> * gnu/services/databases.scm: New file.
> * gnu-system.am (GNU_SYSTEM_MODULES): Add it.
> * doc/guix.texi ("Database Services"): New subsubsection.

Nice!  I haven=E2=80=99t tested it, but it looks good.  I only have minor
comments:

> +;;; Copyright =C2=A9 2015

Line truncated.  :-)

> +(define %default-postgres-hba
> +  (text-file* "pg_hba.conf"
> +              "local	all	all			trust\n"
> +              "host	all	all	127.0.0.1/32 	trust\n"
> +              "host	all	all	::1/128 	trust\n"))
> +
> +(define %default-postgres-ident
> +  (text-file* "pg_ident.conf"
> +              "# MAPNAME       SYSTEM-USERNAME         PG-USERNAME"))

Since these two are purely text (they do not contain references to store
items), =E2=80=98text-file=E2=80=99 is enough and even better.

(=E2=80=98text-file*=E2=80=99 returns a derivation that builds the file, an=
d that
derivation depends on Guile; conversely, =E2=80=98text-file=E2=80=99 simply=
 creates a
new file in the store.)

> +          ;; Drop privileges and init state directory in a new
> +          ;; process.  Wait for it to finish before proceeding.
> +          (match (primitive-fork)
> +            (0
> +             (setgid (passwd:gid user))
> +             (setuid (passwd:uid user))
> +             (primitive-exit (system* initdb "-D" #$data-directory)))

It may be a good idea to wrap the child process=E2=80=99s body in:

  (dynamic-wind
    (const #t)
    (lambda ()
      ...)
    (lambda ()
      (primitive-exit 1)))

This makes sure that it doesn=E2=80=99t keep going if an exception is thrown
(yes it=E2=80=99s quite ugly.)

OK to push with these changes!

Thanks,
Ludo=E2=80=99.