Re: [PATCH] daemon: add --no-syslog to undo implicit --syslog

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 24, 2018, 18:33 UTC
Message-ID: <xmqqtvvbds42.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <18ef807d-a642-17b2-fc32-af0c3b963a71@lucaswerkmeister.de>

Lucas Werkmeister <mail@lucaswerkmeister.de> writes:

Show 10 quoted lines

>> Moreover, --detach completely dissociates the process from the
>> original set of standard file descriptors by first closing them and
>> then connecting it to "/dev/null", so it will be nonsense to use this
>> new option with it.
>
> Ah, I wasn’t aware of that – so with --detach, --no-syslog would be
> better described as “disables all logging” rather than “log to stderr
> instead”. IMHO it would still make sense to have the --no-syslog option
> (then mainly for use with --inetd) as long as its interaction with
> --inetd is properly documented.

Because "--detach --no-syslog" is a roundabout way to ask for sending the log to _nowhere_, I actually would say that "nonsense" is a bit too strong a word for the combination of your thing with "--detach".

It might make more sense to introduce a new "--send-log-to=<dest>" option, where the destination can be one of: syslog, stderr, none.

The you can make the current "--syslog" option a synonym to "--send-log-to=syslog". The internal variable log_syslog would probably become

	enum log_destination { 
		LOG_TO_NONE = -1,
		LOG_TO_STDERR = 0,
		LOG_TO_SYSLOG = 1,
	} log_destination;

and wherever the current code assigns 1 to log_syslog, you would be setting it LOG_TO_SYSLOG.

Then those who want no log can express that wish in a more direct way, i.e. "daemon --send-log-to=none", perhaps.

Such an approach leaves open room for future enhancement. It is not too far-fetched to imagine something like:

	git daemon --send-log-to=/var/log/git-daemon.log

by introducing the fourth value to "enum log_destination"; perhaps the file is opened and connected to stderr to accept the logs, combined with a new feature that tells the daemon to close and reopen the log file when it receives a HUP or something like that.