syslog-ng Open Source Edition 3.16 - Administration Guide

Example: Selecting messages using the in-list filter

Create a text file that contains the programs (as in the ${PROGRAM} field of their log messages) you want to select. For example, you want to forward only the logs of a few applications from a host: kernel, sshd, and sudo. Create the /etc/syslog-ng/programlist.list file with the following contents:

kernel
sshd
sudo

The following filter selects only the messages of the listed applications:

filter f_whitelist { in-list("/etc/syslog-ng/programlist.list", value("PROGRAM")); };

Create the appropriate sources and destinations for your environment, then create a log path that uses the previous filter to select only the log messages of the applications you need:

log {
    source(s_all);
    filter(f_whitelist);
    destination(d_logserver); };

To create a blacklist filter, simply negate the in-list filter:

filter f_blacklist { not in-list("/etc/syslog-ng/programlist.list", value("PROGRAM")); };