This configuration sends all (or part of) your OpenWRT logs to a MQTT broker. I'm writing it up here for future reference.
I made this so I can keep track of wireless clients as they associate and disassociate with my home network. This way, my home automation setup can make decisions based on that information. :)
# We need syslog-ng first
opkg update
opkg install syslog-ng # new package = opkg install syslog-ng3
# Edit your configuration according to the other files in this Gist...
# Disable the regular logger
/etc/init.d/log disable
/etc/init.d/log stop
# Enable syslog-ng on boot and start it
/etc/init.d/syslog-ng enable
/etc/init.d/syslog-ng start
nano /usr/bin/log_mqtt_publish
chmod +x /usr/bin/log_mqtt_publish
nano /etc/syslog-ng.conf
nano /etc/syslog-ng.d/mosquitto.conf
/etc/init.d/syslog-ng restart