[syslog-ng]conflict with redhat init scripts

Michael Stenner mstenner@phy.duke.edu
Fri, 13 Jul 2001 08:46:56 -0400

I'm using syslog-ng 1.4.11 on a redhat 7.1 machine and have discovered
a conflict involving the way syslog-ng forks and exits, and the way
redhat starts its daemons.  I don't think either end is really doing
anything wrong here, but I think some things could be tidied up a bit.

Basically, I think it comes from the fact that when syslog-ng forks,
the parent waits for the child to send it a SIGTERM, and then dies
with exit code 0.  Unfortunately, I think that initlog (the redhat
tool for starting daemons and logging the results) is thinking that
the daemon was sent an uncaught SIGTERM and is dying.

Let me give you some examples of what I mean.

When you use bash to start syslog-ng and then print the "exit status",
$?, bash reports 143.  From the bash manpage:

	When a command terminates on a fatal signal N, bash uses the
	value of 128+N as the exit status.  

143 - 128 = 15 = SIGTERM

When you use initlog to start syslog-ng, initlog returns 15 directly.
It also logs (via syslog-ng, humorously) that syslog-ng failed to
start.  Consequently, the init script reports failure.

I'm still confused about a couple of things.

1) I've trolled through the syslog-ng source, and It's clear that the
   TERM signal _should_ be caught, so why are bash and initlog
   detecting this?

2) I've trolled through the initlog source, and I can't find where
   initlog tries to detect the type of signal a program received, or
   even that it cares.  As far as I can tell, it just looks for the
   exit value of the program.

As you can see, I'm already hip-deep in both programs, so I'm
certainly willing to try and help "fix" this.  I'm just wondering
about these last two points, and which end it would be best to fix it
on.  (the fact that bash reports as it does leads me to lean toward
changing this behavior in syslog-ng)


P.S.  If anyone is interesting in doing the same source-diving that
I've been doing, you can get the same things I've been using from:



source rpms can be unpacked to an arbitrary tmpdir with the following

mkdir -p $SRCDIR/usr/src/redhat
rpm --root $SRCDIR --install syslog-ng-1.4.11-3.src.rpm
cd $SRCDIR/usr/src/redhat/SOURCES/

The rest should be obvious.

  Michael Stenner			Office Phone: 919-660-2513
  Duke University, Dept. of Physics	  mstenner@phy.duke.edu
  Box 90305, Durham N.C. 27708-0305