main.go

package main

import (
	"log"
	"net"
	"net/http"
	"os"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"github.com/rydyb/devices/srs"
)

var (
	controllerAddress = os.Getenv("CONTROLLER_ADDRESS")
	prometheusAddress = os.Getenv("PROMETHEUS_ADDRESS")
)

const (
	prometheusNamespace = "vacuum_apparatus"
	prometheusSubsystem = "atomic_beam_system"
)

var (
	hw_temp = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: prometheusNamespace,
		Subsystem: prometheusSubsystem,
		Name:      "hot_window_temperature_celsius",
	})
	hw_curr = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: prometheusNamespace,
		Subsystem: prometheusSubsystem,
		Name:      "hot_window_current_amperes",
	})
	oven_temp = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: prometheusNamespace,
		Subsystem: prometheusSubsystem,
		Name:      "oven_temperature_celsius",
	})
	oven_power = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: prometheusNamespace,
		Subsystem: prometheusSubsystem,
		Name:      "oven_power_watts",
	})
)

func main() {
	conn, err := net.Dial("tcp", controllerAddress)
	if err != nil {
		log.Fatalf("failed to connect to controller: %s", err)
	}
	defer conn.Close()

	ptc10 := srs.NewPTC10(conn)
	promhandler := promhttp.Handler()

	http.Handle("/metrics", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		outputs, err := ptc10.Outputs()
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			log.Fatalf("failed to get outputs: %s", err)
			return
		}

		hw_temp.Set(outputs["HW TC"])
		hw_curr.Set(outputs["HW Out"])
		oven_temp.Set(outputs["Oven TC"])
		oven_power.Set(outputs["Oven Out"])

		promhandler.ServeHTTP(w, r)
	}))
	if err := http.ListenAndServe(prometheusAddress, nil); err != nil {
		log.Fatalf("failed to listen and serve to %s: %s", prometheusAddress, err)
	}
}