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I want to have a rsyslog log its data to a fifo that a daemon creates. However, if the daemon isn't running and the fifo isn't there then rsyslog will just start writing to a file in its place.

Is there any way I can prevent this from happening?

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What should happen to the log entries if the daemon isn't listening? Can they get lost, or should something (what) buffer them? – Gilles Mar 29 '11 at 22:09
@Gilles: I already send them to log files with another syslog entry ... just no sense in doubling them. – Kyle Brandt♦ Mar 29 '11 at 22:10

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If you have any control over the way the daemon is started, tell rsyslog to log to a UDP port and pipe the data into the daemon with netcat:

nc -u -l localhost 53396 | daemon --read-from-stdin

That way, if the daemon isn't available, entries will be discarded.

If you supervise the daemon, it'll be available almost all the time anyway.

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Was thinking about just doing that... I wrote the daemon, so I have control :-) Just have to learn how to read line by line from UDP port... – Kyle Brandt♦ Mar 29 '11 at 22:47
@KyleBrandt: Now I'm confused: wouldn't netcat completely insulate your daemon from UDP? – Gilles Mar 29 '11 at 23:18
@Gillies: Ya, but cleaner just to put what netcat does in python itself if I can I think – Kyle Brandt♦ Mar 29 '11 at 23:28
That feels like an awful lot of moving parts just to write to a fifo. We tailor our syslog-ng init script to ensure the fifos we write to are in place before the service can start. – Jeff Albert Mar 30 '11 at 1:55

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