Re: Defaulting to MAC-based names for network interfaces

[Felix Lechner via "Development of GNU Guix and the GNU System distribution." <guix-devel@gnu.org>]

Hi Efraim,

On Mon, May 15, 2023 at 7:47 AM Efraim Flashner <efraim@flashner.co.il> wrote:
>
> > the standard command to test udev setups: [2]
> >
> >   $ udevadm --debug test /sys/class/net/*
> >
> > did not find the script installed via the 'udev-service-type'.
>
> I was curious about this, since I've been using a udev rule for quite a
> while to setup zram swap. I definitely have my zram swap enabled and
> working, but 'udevadm --debug test /dev/zram0' didn't find any rule for
> zram.

Your zram probably works because your udev rule does not need a
working udevadm. I believe that network interfaces actually use
udevadm to determine their name. Either way, my latest amendments to
Bug#63508 (v2) will fix your udevadm. [1]

In a concession to Liliana's opposition, I retitled the bug to
sidestep the question of the MAC-based names as a default setting. My
position has not changed but that should probably be a separate
discussion.

Personally, I hope to win everyone's hearts with this: My fix allows
folks to experiment with MAC-based names so everyone can see their
great utility. Anyone interested, please put this in your system
services:

            (udev-rules-service 'net-name-mac
                                (udev-rule
                                 "79-net-name-mac.rules"
                                 "
SUBSYSTEM==\"net\", ACTION==\"add\", NAME=\"$env{ID_NET_NAME_MAC}\"
")))

Sorry I cannot offer substitutes. The change rebuilds more than it should.

As a side note, I looked into upgrading to eudev 3.2.12, which was
tagged yesterday, but that will bring more pain because upstream
hardcoded the path to the hwdb. [2] I have a partial fix, although
some consuming packages like upower aren't working yet.

Kind regards
Felix

[1] https://issues.guix.gnu.org/63508#12
[2] https://github.com/eudev-project/eudev/blob/2703baf55615b7554fb67c4f1c241f057f8c0a79/src/udev/udevadm-hwdb.c#L588