You can create a failure script that is executed when syslog-ng OSE terminates abnormally, that is, when it exits with a non-zero exit code. For example, you can use this script to send an automatic email notification.

Prerequisites

The failure script must be the following file: /opt/syslog-ng/sbin/syslog-ng-failure, and must be executable.

To create a sample failure script, complete the following steps.

Steps

  1. Create a file named /opt/syslog-ng/sbin/syslog-ng-failure with the following content:

     #!/usr/bin/env bash
 cat >>/tmp/test.txt <<EOF
 $(date)
 Name............$1
 Chroot dir......$2
 Pid file dir....$3
 Pid file........$4
 Cwd.............$5
 Caps............$6
 Reason..........$7
 Argbuf..........$8
 Restarting......$9

 EOF

  2. Make the file executable: chmod +x /opt/syslog-ng/sbin/syslog-ng-failure

  3. Run the following command in the /opt/syslog-ng/sbin directory:

     ./syslog-ng --process-mode=safe-background; sleep 0.5; ps aux |
 grep './syslog-ng' | grep -v grep | awk '{print $2}' | xargs
 kill -KILL; sleep 0.5; cat /tmp/test.txt

    The command starts syslog-ng OSE in safe-background mode (which is needed to use the failure script) and then kills it. You should see that the relevant information is written into the /tmp/test.txt file, for example:

     Thu May 18 12:08:58 UTC 2017
 Name............syslog-ng
 Chroot dir......NULL
 Pid file dir....NULL
 Pid file........NULL
 Cwd.............NULL
 Caps............NULL
 Reason..........signalled
 Argbuf..........9
 Restarting......not-restarting

  4. You should also see messages similar to the following in system syslog. The exact message depends on the signal (or the reason why syslog-ng OSE stopped):

    May 18 13:56:09 myhost supervise/syslog-ng[10820]: Daemon exited gracefully, not restarting; exitcode=’0’ May 18 13:57:01 myhost supervise/syslog-ng[10996]: Daemon exited due to a deadlock/signal/failure, restarting; exitcode=’131’ May 18 13:57:37 myhost supervise/syslog-ng[11480]: Daemon was killed, not restarting; exitcode=’9’

    The failure script should run on every non-zero exit event.

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