Add prom exporter

exporter.go

@@ -9,6 +9,8 @@ package main
 import (
 	"flag"
 	"fmt"
+	"log"
+	"net/http"
 	"os"
 	"os/signal"
 	"regexp"
@@ -16,6 +18,10 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+
 	"periph.io/x/conn/v3/i2c/i2creg"
 	"periph.io/x/conn/v3/physic"
 	"periph.io/x/devices/v3/ina219"
@@ -26,8 +32,9 @@ func mainImpl() error {
 	if _, err := host.Init(); err != nil {
 		return err
 	}
-	address := flag.Int("address", 0x45, "I²C address")
+	httpAddr := flag.String("http-address", ":9455", "Listen addr for HTTP handler")
-	i2cbus := flag.String("bus", "", "I²C bus (/dev/i2c-1)")
+	i2cAddress := flag.Int("i2c-address", 0x45, "I²C address")
+	i2cBus := flag.String("i2c-bus", "", "I²C bus (/dev/i2c-1)")
 	senseResistor := flag.String("sense-resistor", "10m", "Resistance of the shunt resistor in ohms (optionally with suffix m = milli, {µ,mu} = micro, n = nano)")
 	maxCurrent := flag.String("max-current", "8", "Maximum current through the device in amps (optional suffix as for --sense-resistor)")
 
@@ -53,14 +60,14 @@ func mainImpl() error {
 	}
 
 	// Open default I²C bus.
-	bus, err := i2creg.Open(*i2cbus)
+	bus, err := i2creg.Open(*i2cBus)
 	if err != nil {
 		return fmt.Errorf("failed to open I²C: %v", err)
 	}
 	defer bus.Close()
 
 	sensor, err := ina219.New(bus, &ina219.Opts{
-		Address:       *address,
+		Address:       *i2cAddress,
 		SenseResistor: resistor,
 		MaxCurrent:    current,
 	})
@@ -68,13 +75,51 @@ func mainImpl() error {
 		return fmt.Errorf("failed to open new sensor: %v", err)
 	}
 
+	constLabels := prometheus.Labels{"i2c-addr": fmt.Sprintf("0x%x", *i2cAddress)}
+	busVoltageHist := promauto.NewHistogram(prometheus.HistogramOpts{
+		Namespace:                    "ina219",
+		Name:                         "bus_voltage",
+		Help:                         "Bus voltage (V)",
+		ConstLabels:                  constLabels,
+		NativeHistogramBucketFactor:  1.001,
+		NativeHistogramZeroThreshold: 0.001,
+	})
+	busCurrentHist := promauto.NewHistogram(prometheus.HistogramOpts{
+		Namespace:                    "ina219",
+		Name:                         "bus_current",
+		Help:                         "Bus current (A)",
+		ConstLabels:                  constLabels,
+		NativeHistogramBucketFactor:  1.001,
+		NativeHistogramZeroThreshold: 0.001,
+	})
+	busPowerHist := promauto.NewHistogram(prometheus.HistogramOpts{
+		Namespace:                    "ina219",
+		Name:                         "bus_power",
+		Help:                         "Bus power (W)",
+		ConstLabels:                  constLabels,
+		NativeHistogramBucketFactor:  1.001,
+		NativeHistogramZeroThreshold: 0.001,
+	})
+	shuntVoltageHist := promauto.NewHistogram(prometheus.HistogramOpts{
+		Namespace:                    "ina219",
+		Name:                         "shunt_voltage",
+		Help:                         "Shunt voltage (V)",
+		ConstLabels:                  constLabels,
+		NativeHistogramBucketFactor:  1.001,
+		NativeHistogramZeroThreshold: 0.001,
+	})
+
+	go func() {
+		http.Handle("/metrics", promhttp.Handler())
+		log.Fatal(http.ListenAndServe(*httpAddr, nil))
+	}()
+
 	// Read values from sensor every second.
 	everySecond := time.NewTicker(time.Second).C
-	var halt = make(chan os.Signal, 1)
+	halt := make(chan os.Signal, 1)
 	signal.Notify(halt, syscall.SIGTERM)
 	signal.Notify(halt, syscall.SIGINT)
 
-	fmt.Println("ctrl+c to exit")
 	for {
 		select {
 		case <-everySecond:
@@ -82,7 +127,11 @@ func mainImpl() error {
 			if err != nil {
 				return fmt.Errorf("sensor reading error: %v", err)
 			}
-			fmt.Println(p)
+			busVoltageHist.Observe(float64(p.Voltage) / float64(physic.Volt))
+			busCurrentHist.Observe(float64(p.Current) / float64(physic.Ampere))
+			busPowerHist.Observe(float64(p.Power) / float64(physic.Watt))
+			shuntVoltageHist.Observe(float64(p.Shunt) / float64(physic.Volt))
+
 		case <-halt:
 			return nil
 		}

go.mod

@@ -3,8 +3,20 @@ module gitea.drjosh.dev/josh/ina219-exporter
 go 1.23.1
 
 require (
-	github.com/dustin/go-humanize v1.0.1
+	github.com/prometheus/client_golang v1.20.4
 	periph.io/x/conn/v3 v3.7.1
 	periph.io/x/devices/v3 v3.7.1
 	periph.io/x/host/v3 v3.8.2
 )
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/prometheus/client_model v0.6.1 // indirect
+	github.com/prometheus/common v0.55.0 // indirect
+	github.com/prometheus/procfs v0.15.1 // indirect
+	golang.org/x/sys v0.22.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
+)

go.sum

@@ -1,7 +1,29 @@
-github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
-github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/jonboulle/clockwork v0.4.0 h1:p4Cf1aMWXnXAUh8lVfewRBx1zaTSYKrKMF2g3ST4RZ4=
 github.com/jonboulle/clockwork v0.4.0/go.mod h1:xgRqUGwRcjKCO1vbZUEtSLrqKoPSsUpK7fnezOII0kc=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/prometheus/client_golang v1.20.4 h1:Tgh3Yr67PaOv/uTqloMsCEdeuFTatm5zIq5+qNN23vI=
+github.com/prometheus/client_golang v1.20.4/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
+github.com/prometheus/client_model v0.6.1 h1:ZKSh/rekM+n3CeS952MLRAdFwIKqeY8b62p8ais2e9E=
+github.com/prometheus/client_model v0.6.1/go.mod h1:OrxVMOVHjw3lKMa8+x6HeMGkHMQyHDk9E3jmP2AmGiY=
+github.com/prometheus/common v0.55.0 h1:KEi6DK7lXW/m7Ig5i47x0vRzuBsHuvJdi5ee6Y3G1dc=
+github.com/prometheus/common v0.55.0/go.mod h1:2SECS4xJG1kd8XF9IcM1gMX6510RAEL65zxzNImwdc8=
+github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
+github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
+golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
+golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 periph.io/x/conn/v3 v3.7.1 h1:tMjNv3WO8jEz/ePuXl7y++2zYi8LsQ5otbmqGKy3Myg=
 periph.io/x/conn/v3 v3.7.1/go.mod h1:c+HCVjkzbf09XzcqZu/t+U8Ss/2QuJj0jgRF6Nye838=
 periph.io/x/devices/v3 v3.7.1 h1:BsExlfYJlZUZoawzpMF7ksgC9f1eBAdqvKRCGvb+VYw=