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Subject: [bug#30498] [WIP v2 shepherd] shepherd: If /dev/kmsg is writable,
	use it for logging.
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From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
References: <20180217122035.1443-1-dannym@scratchpost.org>
	<20180217164835.1178-1-dannym@scratchpost.org>
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Date: Mon, 05 Mar 2018 17:51:44 +0100
In-Reply-To: <20180303233715.7ec8a08c@scratchpost.org> (Danny Milosavljevic's
	message of "Sat, 3 Mar 2018 23:37:15 +0100")
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To: Danny Milosavljevic <dannym@scratchpost.org>
Cc: 30498@debbugs.gnu.org

Heya,

I took the liberty to split this in several patches, which I think makes
it easier to follow.  I omitted the bits about redirecting stderr, for
now, to simplify things.

I tested it in a GuixSD VM and it works as advertised!  \o/

There=E2=80=99s one thing we need to improve though: syslogd reads /proc/km=
sg
and prefixes everything that comes from there with =E2=80=9Cvmunix=E2=80=9D=
 (as if it
came from the kernel).  That=E2=80=99s inconvenient because it makes it
impossible to have syslogd rules to filter shepherd messages.

So I think we need to do instead use a =E2=80=98syslog=E2=80=99-style inter=
face and,
similar to what =E2=80=98syslog=E2=80=99 does in glibc, write to /dev/log u=
nless it=E2=80=99s
unavailable, in which case we fall back to /dev/kmsg.

Thoughts?

I=E2=80=99ll see if I can give it a try.

Thanks,
Ludo=E2=80=99.