simplistic WIP of a prometheus exporter for gpsd

go.mod

@@ -0,0 +1,17 @@
+module laf0rge/gps2prom
+
+go 1.19
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_golang v1.14.0 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
+	github.com/stratoberry/go-gpsd v1.0.0 // indirect
+	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
+)

gps2prom.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"fmt"
+	"github.com/stratoberry/go-gpsd"
+
+	"net/http"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var (
+	gpsMode = promauto.NewGauge(
+		prometheus.GaugeOpts {
+			Subsystem:	"gpsd",
+			Name: 		"mode",
+			Help:		"gpsd mode (2=2D fix, 3=3D fix)",
+		})
+
+	gpsNumSats = promauto.NewGauge(
+		prometheus.GaugeOpts {
+			Subsystem:	"gpsd",
+			Name:		"num_sv_total",
+			Help:		"Total number of SV",
+		})
+	gpsNumSatsUsed = promauto.NewGauge(
+		prometheus.GaugeOpts {
+			Subsystem:	"gpsd",
+			Name:		"num_sv_used",
+			Help:		"Used number of SV",
+		})
+)
+
+func main() {
+	var gps *gpsd.Session
+	var err error
+
+	if gps, err = gpsd.Dial("apu-left:2947"); err != nil {
+		panic(fmt.Sprintf("Failed to connect to GPSD: %s", err))
+	}
+
+	gps.AddFilter("TPV", func(r interface{}) {
+		tpv := r.(*gpsd.TPVReport)
+		//fmt.Println("TPV", tpv.Mode, tpv.Time)
+		gpsMode.Set(float64(tpv.Mode))
+	})
+
+	/*
+	gps.AddFilter("DEVICE", func(r interface{}) {
+		dev := r.(*gpsd.DEVICEReport)
+		fmt.Println("DEVICE", dev.Path, dev.Flags)
+	})
+	*/
+
+	gps.AddFilter("SKY", func(r interface{}) {
+		sky := r.(*gpsd.SKYReport)
+		fmt.Println("SKY", sky.Satellites)
+		gpsNumSats.Set(float64(len(sky.Satellites)))
+
+		num_sats_used := 0
+		for i := 0; i < len(sky.Satellites); i++ {
+			num_sats_used += 1
+		}
+		gpsNumSatsUsed.Set(float64(num_sats_used))
+	})
+
+
+	fmt.Println("Hello, World!")
+
+	done := gps.Watch()
+
+	http.Handle("/metrics", promhttp.Handler())
+	http.ListenAndServe(":2112", nil)
+
+	<-done
+}