librenms-librenms/includes/discovery/processors/fortigate.inc.php

<?php

//
// Hardcoded discovery of cpu usage on Fortigate devices.
//
// FORTINET-FORTIGATE-MIB::fgSysCpuUsage.0
if ($device['os'] == 'fortigate') {
    echo 'Fortigate : ';

    $descr = 'Processor';
    $usage = snmp_get($device, '.1.3.6.1.4.1.12356.101.4.1.3.0', '-Ovq');

    if (is_numeric($usage)) { 
        discover_processor($valid['processor'], $device, '.1.3.6.1.4.1.12356.101.4.1.3.0', '0', 'fortigate-fixed', $descr, '1', $usage, null, null);
    }
}

unset($processors_array);