Add support for prometheus

stats/prometheus.go

@@ -0,0 +1,80 @@
+package stats
+
+import (
+	"time"
+
+	"github.com/juju/errors"
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/9seconds/mtg/config"
+)
+
+const prometheusPollTime = time.Second
+
+type prometheusExporter struct {
+	connections *prometheus.GaugeVec
+	traffic     *prometheus.GaugeVec
+	speed       *prometheus.GaugeVec
+	crashes     prometheus.Gauge
+}
+
+func (p *prometheusExporter) run() {
+	for range time.Tick(prometheusPollTime) {
+		instance := GetStats()
+
+		p.connections.WithLabelValues("abridged", "v4").Set(float64(instance.Connections.Abridged.IPv4))
+		p.connections.WithLabelValues("abridged", "v6").Set(float64(instance.Connections.Abridged.IPv6))
+		p.connections.WithLabelValues("intermediate", "v4").Set(float64(instance.Connections.Intermediate.IPv4))
+		p.connections.WithLabelValues("intermediate", "v6").Set(float64(instance.Connections.Intermediate.IPv6))
+		p.connections.WithLabelValues("secure", "v4").Set(float64(instance.Connections.Secure.IPv4))
+		p.connections.WithLabelValues("secure", "v6").Set(float64(instance.Connections.Secure.IPv6))
+		p.traffic.WithLabelValues("ingress").Set(float64(instance.Traffic.ingress))
+		p.traffic.WithLabelValues("egress").Set(float64(instance.Traffic.egress))
+		p.speed.WithLabelValues("ingress").Set(float64(instance.Speed.ingress))
+		p.speed.WithLabelValues("egress").Set(float64(instance.Speed.egress))
+		p.crashes.Set(float64(instance.Crashes))
+	}
+}
+
+func newPrometheus(conf *config.Config) (*prometheusExporter, error) {
+	connections := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: conf.Prometheus.Prefix,
+		Name:      "connections",
+		Help:      "Current number of connections to the proxy.",
+	}, []string{"type", "protocol"})
+	traffic := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: conf.Prometheus.Prefix,
+		Name:      "traffic",
+		Help:      "Traffic passed through the proxy in bytes.",
+	}, []string{"direction"})
+	speed := prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: conf.Prometheus.Prefix,
+		Name:      "speed",
+		Help:      "Current throughput in bytes per second.",
+	}, []string{"direction"})
+	crashes := prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: conf.Prometheus.Prefix,
+		Name:      "crashes",
+		Help:      "How many crashes happened.",
+	})
+
+	if err := prometheus.Register(connections); err != nil {
+		return nil, errors.Annotate(err, "Cannot register connections collector")
+	}
+	if err := prometheus.Register(traffic); err != nil {
+		return nil, errors.Annotate(err, "cannot register traffic collector")
+	}
+	if err := prometheus.Register(speed); err != nil {
+		return nil, errors.Annotate(err, "cannot register speed collector")
+	}
+	if err := prometheus.Register(crashes); err != nil {
+		return nil, errors.Annotate(err, "cannot register crashes collector")
+	}
+
+	return &prometheusExporter{
+		connections: connections,
+		traffic:     traffic,
+		speed:       speed,
+		crashes:     crashes,
+	}, nil
+}