From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: networkmanager hostname woes
Date: Thu, 14 Sep 2017 10:17:08 +0200
Message-ID: <878thhd797.fsf@gnu.org>
References: <20170913.120529.1808480687765633530.thomas.danckaert@aeronomie.be>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <help-guix-bounces+gcggh-help-guix=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:39698)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1dsPKl-0004Cn-Hw
	for help-guix@gnu.org; Thu, 14 Sep 2017 04:17:19 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <ludo@gnu.org>) id 1dsPKg-0008PC-J5
	for help-guix@gnu.org; Thu, 14 Sep 2017 04:17:15 -0400
In-Reply-To: <20170913.120529.1808480687765633530.thomas.danckaert@aeronomie.be>
	(Thomas Danckaert's message of "Wed, 13 Sep 2017 12:05:29 +0200
	(CEST)")
List-Id: <help-guix.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/help-guix>,
	<mailto:help-guix-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/help-guix/>
List-Post: <mailto:help-guix@gnu.org>
List-Help: <mailto:help-guix-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/help-guix>,
	<mailto:help-guix-request@gnu.org?subject=subscribe>
Errors-To: help-guix-bounces+gcggh-help-guix=m.gmane.org@gnu.org
Sender: "Help-Guix" <help-guix-bounces+gcggh-help-guix=m.gmane.org@gnu.org>
To: Thomas Danckaert <thomas.danckaert@aeronomie.be>
Cc: help-guix@gnu.org

Hi Thomas,

Thomas Danckaert <thomas.danckaert@aeronomie.be> skribis:

> AFAIU, the cause is that networkmanager changes my hostname

I=E2=80=99ve never experienced this (even though I don=E2=80=99t have /etc/=
hostname),
but that looks like a serious bug we should fix.  Why would NM fiddle
with the host name?

I see that NM implements a =E2=80=9CSetHostname=E2=80=9D D-Bus RPC, and =E2=
=80=98nmtui=E2=80=99 has a
menu item to change the host name.

In NM, the =E2=80=98update_system_hostname=E2=80=99 function has this comme=
nt:

	/* Hostname precedence order:
	 *
	 * 1) a configured hostname (from settings)
	 * 2) automatic hostname from the default device's config (DHCP, VPN, etc)
	 * 3) the last hostname set outside NM
	 * 4) reverse-DNS of the best device's IPv4 address
	 *
	 */

Then nm-settings.c has code to deal with host names in all sort of
unpredictable ways.  To give you an idea:

--8<---------------cut here---------------start------------->8---
#define HOSTNAME_FILE_DEFAULT        "/etc/hostname"
#define HOSTNAME_FILE_UCASE_HOSTNAME "/etc/HOSTNAME"
#define HOSTNAME_FILE_GENTOO         "/etc/conf.d/hostname"

[...]

#if defined(HOSTNAME_PERSIST_SUSE)
#define HOSTNAME_FILE           HOSTNAME_FILE_UCASE_HOSTNAME
#elif defined(HOSTNAME_PERSIST_SLACKWARE)
#define HOSTNAME_FILE           HOSTNAME_FILE_UCASE_HOSTNAME
#elif defined(HOSTNAME_PERSIST_GENTOO)
#define HOSTNAME_FILE           HOSTNAME_FILE_GENTOO
#else
#define HOSTNAME_FILE           HOSTNAME_FILE_DEFAULT
#endif

[...]

static gchar *
read_hostname_gentoo (const char *path)
--8<---------------cut here---------------end--------------->8---

So, like Chris wrote, it honors /etc/hostname or /etc/HoSTNaM3 depending
on the phase of the moon.

I don=E2=80=99t understand the logic in there, but a quick fix would be to =
have
=E2=80=98network-manager-service-type=E2=80=99 create /etc/hostname.

What do people think?

Ludo=E2=80=99.