Agent setup

To gather data from remote systems you can use LibreNMS in combination with check_mk (included in the librenms-agent repository).

The agent uses TCP-Port 6556, please allow access from the LibreNMS-Host and Poller-Nodes if you're using the Distributed Polling setup.

On each of the hosts you would like to use the agent on then you need to do the following:

• Copy the check_mk_agent script into /usr/bin and make it executable.

cp check_mk_agent /usr/bin/check_mk_agent
chmod +x /usr/bin/check_mk_agent

• Copy the xinetd config file into place.

cp check_mk_xinetd /etc/xinetd.d/check_mk

• Create the relevant directories.

mkdir -p /usr/lib/check_mk_agent/plugins /usr/lib/check_mk_agent/local

• Copy each of the scripts from agent-local/ into /usr/lib/check_mk_agent/local
• And restart xinetd.

/etc/init.d/xinetd restart

• Login to the LibreNMS web interface and edit the device you want to monitor. Under the modules section, ensure that unix-agent is enabled.
• Then under Applications, enable the apps that you plan to monitor.
• Wait, in around 10 minutes you should start seeing data in your graphs under Apps for the device.

Application Specific Configuration

BIND9/named

Create stats file with appropriate permissions:

~$ touch /etc/bind/named.stats
~$ chown bind:bind /etc/bind/named.stats

Change user:group to the user and group that's running bind/named.

Bind/named configuration:

options {
	...
	statistics-file "/etc/bind/named.stats";
	zone-statistics yes;
	...
};

Restart your bind9/named after changing the configuration.

Verify that everything works by executing rndc stats && cat /etc/bind/named.stats.
In case you get a Permission Denied error, make sure you chown'ed correctly.

Note: if you change the path you will need to change the path in agent-local/bind.

TinyDNS/djbdns

Installation:

1. Get tinystats sources from http://www.morettoni.net/tinystats.en.html
2. Compile like as advised.
   Note: In case you get Makefile:9: *** missing separator. Stop., compile manually using:
   • With IPv6: gcc -Wall -O2 -fstack-protector -DWITH_IPV6 -o tinystats tinystats.c
   • Without IPv6: gcc -Wall -O2 -fstack-protector -o tinystats tinystats.c
3. Install into prefered path, like /usr/bin/.

Configuration:

Note: In this part we assume that you use DJB's Daemontools to start/stop tinydns.
And that your tinydns-instance is located in /service/dns, adjust this path if necesary.

1. Replace your log's run file, typically located in /service/dns/log/run with:

#!/bin/sh

exec setuidgid dnslog tinystats ./main/tinystats/ multilog t n3 s250000 ./main/

2. Create tinystats directory and chown:
   mkdir /service/dns/log/main/tinystats && chown dnslog:nofiles /service/dns/log/main/tinystats
3. Restart TinyDNS and Daemontools: /etc/init.d/svscan restart
   Note: Some say svc -t /service/dns is enough, on my install (Gentoo) it doesnt rehook the logging and I'm forced to restart it entirely.

MySQL

Unlike most other scripts, the MySQL script requires a configuration file /usr/lib/check_mk_agent/local/mysql.cnf with following content:

<?php
$mysql_user = 'root';
$mysql_pass = 'toor';
$mysql_host = 'localhost';
$mysql_port = 3306;

NOTE: This only applies to the PHP-Version of the Statistics-poller. There's work being done in porting this script to Python, a different configuration file (if any) will apply.

Nginx

It's required to have the following directive in your nginx-configuration responsible for the localhost-server:

location /nginx-status {
    stub_status on;
    access_log   off;
    allow 127.0.0.1;
    deny all;
}