Publish openwrt log contents to MQTT

.syslog-ng.md

Router logging to MQTT

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. :)

Installation

# 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

log_mqtt_publish

#!/bin/sh
#/usr/bin/log_mqtt_publish

# OPENWRT mosquitto
thishostname="`uci get system.@system[0].hostname`"
thisdomain="`uci get dhcp.@dnsmasq[0].domain`"

while read line; do
  #echo "$line";
  mosquitto_pub -h localhost -p 1883 -t "openwrt/$thisdomain/$thishostname/syslog" -m "${line}" -q 1
done

mosquitto.conf

@version:3.9
#/etc/syslog-ng.d/mosquitto.conf

# Define some filters if you want to (untested)
filter f_associated {
	match(".*IEEE 802.11.*", value("MESSAGE"));
};

destination d_mqtt {
  # The first argument is a program (or script) that gets spawned when syslog-ng starts, and keeps running until it stops again.
  # The log messages are sent to stdin on that program.
	program("ash /usr/bin/log_mqtt_publish" template("${MESSAGE}\n") );
};

# Log to MQTT
log {
	source(src);
	source(net);
	source(kernel);
	# Apply any filters here
	# filter(f_associated);
	destination(d_mqtt);
};

syslog-ng.conf

@version:3.9

options {
	chain_hostnames(no);
	create_dirs(yes);
	flush_lines(0);
	keep_hostname(yes);
	log_fifo_size(256);
	log_msg_size(1024);
	stats_freq(0);
	flush_lines(0);
	use_fqdn(no);
};

source src {
	internal();
	#unix-stream("/dev/log");
	unix-dgram("/dev/log");
};

source net {
	udp(ip(0.0.0.0) port(514));
};

source kernel {
  file("/proc/kmsg" program_override("kernel"));
};

destination messages {
	#file("/var/log/messages" log_fifo_size(256));
	file("/var/log/messages");
};

# Log to /var/log/messages
log {
	source(src);
	source(net);
  	source(kernel);
	destination(messages);
};

# put any customization files in this directory
@include "/etc/syslog-ng.d/"