Load averages and PPS with a PiGlow

pcap.js

var pcap = require('pcap');
var piglow = require('piglow');
var eth0 = pcap.createSession('eth0', 'ip proto \\tcp');
var wlan0 = pcap.createSession('wlan0', 'ip proto \\tcp');
var packets_per_sec = {eth0: 0, wlan0: 0};
piglow(function(err, pi) {
    if (err) throw err;
    setInterval(function() {
        pi.startTransaction();
        pi.all = 0;
        console.log(JSON.stringify(packets_per_sec));
        Object.keys(packets_per_sec).forEach(function(iface, i) {
            var packets = packets_per_sec[iface];
            if (packets > 1) pi['l_' + i + '_0'] = 10;
            if (packets > 30) pi['l_' + i + '_1'] = 30;
            if (packets > 60) pi['l_' + i + '_2'] = 60;
            if (packets > 90) pi['l_' + i + '_3'] = 90;
            if (packets > 120) pi['l_' + i + '_4'] = 120;
            if (packets > 150) pi['l_' + i + '_5'] = 150;
        });
        packets_per_sec = {eth0: 0, wlan0: 0};
        var ld = require('os').loadavg()[0];
        if (ld < 0.4) pi.l_2_0 = 10; // Aaaahhhhhh.
        if (ld >= 0.4 && ld < 0.6) pi.l_2_1 = 30;
        if (ld >= 0.6 && ld < 1) pi.l_2_2 = 60;
        if (ld >= 1 && ld < 1.2) pi.l_2_3 = 90; 
        if (ld >= 1.2 && ld < 1.6) pi.l_2_4 = 120;
        if (ld >= 1.6 && ld < 2) pi.l_2_4 = 150;
        if (ld > 2) pi.l_2_5 = 150;
        pi.commitTransaction();
    }, 1000);
    eth0.on('packet', function() {
        packets_per_sec.eth0++;
    });
    wlan0.on('packet', function() {
        packets_per_sec.wlan0++;
    });
});