From: Tom Lane <tgl@sss.pgh.pa.us>
To: pablito.federico@gmail.com
cc: pgsql-docs@lists.postgresql.org
Subject: Re: Server start with systemd and configured with IP address
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Comments: In-reply-to PG Doc comments form <noreply@postgresql.org>
	message dated "Tue, 11 Oct 2022 20:52:54 -0000"
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Date: Wed, 12 Oct 2022 10:38:55 -0400
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PG Doc comments form <noreply@postgresql.org> writes:
> My suggestion is add to the documentation in the segment that shows the
> systemd entry inside the [Unit] segment the line
> After=network-online.target

> I saw in several sites that most people recommends using
> After=network.target

> but this will fail if the server is configured to listen on a specific IP
> address instead of just localhost or 127.0.0.1

Yeah, I have also found with other daemons that if you use specific
IP addresses in the configuration, you need network-online.target.
Some references suggest that you *also* need to say
Wants=network-online.target [1].

It might be that network.target is sufficient if you just bind to
"*", but considering that we're not mentioning that either right
now, I don't see a need to discuss the difference.

(Down the road, maybe we should consider using IP_FREEBIND on
Linux, as suggested at [1] ... although that hobbles error
detection, so I'm not really sold that it's such a great idea.)

			regards, tom lane

[1] https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/