collector.go

package main

import (
	"strconv"
	"sync"

	"github.com/prometheus/client_golang/prometheus"
)

const prefix = "ping_"

var (
	labelNames = []string{"target", "ip", "ip_version"}
	bestDesc   = prometheus.NewDesc(prefix+"rtt_best_ms", "Best round trip time in millis", labelNames, nil)
	worstDesc  = prometheus.NewDesc(prefix+"rtt_worst_ms", "Worst round trip time in millis", labelNames, nil)
	meanDesc   = prometheus.NewDesc(prefix+"rtt_mean_ms", "Mean round trip time in millis", labelNames, nil)
	stddevDesc = prometheus.NewDesc(prefix+"rtt_std_deviation_ms", "Standard deviation in millis", labelNames, nil)
	lossDesc   = prometheus.NewDesc(prefix+"loss_percent", "Packet loss in percent", labelNames, nil)
	progDesc   = prometheus.NewDesc(prefix+"up", "ping_exporter version", nil, prometheus.Labels{"version": version})
	mutex      = &sync.Mutex{}
)

type pingCollector struct {
	targets []*target
}

func (p *pingCollector) Describe(ch chan<- *prometheus.Desc) {
	ch <- lossDesc
	ch <- bestDesc
	ch <- worstDesc
	ch <- meanDesc
	ch <- stddevDesc
	ch <- progDesc
}

func (p *pingCollector) Collect(ch chan<- prometheus.Metric) {
	mutex.Lock()
	defer mutex.Unlock()

	ch <- prometheus.MustNewConstMetric(progDesc, prometheus.GaugeValue, 1)

	for _, t := range p.targets {
		for _, r := range t.runners {
			p.collectForRunner(t, r, ch)
		}
	}
}

func (p *pingCollector) collectForRunner(t *target, r *runner, ch chan<- prometheus.Metric) {
	stats := r.stats
	if stats == nil {
		return
	}

	ipVersion := 6
	if r.ip.To4() != nil {
		ipVersion = 4
	}

	l := []string{t.host, r.ip.String(), strconv.Itoa(ipVersion)}
	ch <- prometheus.MustNewConstMetric(bestDesc, prometheus.GaugeValue, float64(stats.MinRtt.Milliseconds()), l...)
	ch <- prometheus.MustNewConstMetric(worstDesc, prometheus.GaugeValue, float64(stats.MaxRtt.Milliseconds()), l...)
	ch <- prometheus.MustNewConstMetric(meanDesc, prometheus.GaugeValue, float64(stats.AvgRtt.Milliseconds()), l...)
	ch <- prometheus.MustNewConstMetric(stddevDesc, prometheus.GaugeValue, float64(stats.StdDevRtt.Milliseconds()), l...)
	ch <- prometheus.MustNewConstMetric(lossDesc, prometheus.GaugeValue, stats.PacketLoss, l...)
}