app-exporter/app_exporter.go

package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"recycled.cloud/app-exporter/apps"
)

// var so it can be overridden at build time
var VERSION = "dev"

const LISTEN_ADDR = ":9404"
const INTERVAL = 24 * time.Hour

var version_flag = flag.Bool("version", false, "Shows the program version")
var logfile = flag.String("logfile", "-", "Where to write the logs")

func main() {
	flag.Parse()

	if *version_flag {
		fmt.Printf("%v\n", VERSION)
		os.Exit(0)
	}

	if *logfile != "-" {
		f, err := os.OpenFile(*logfile, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0664)
		if err != nil {
			log.Fatalf("Could not open logfile: %v\n", err)
		}
		defer f.Close()
		log.SetOutput(f)
	}

	reg := prometheus.NewRegistry()

	log.Printf("app-exporter version %v\n", VERSION)

	m := apps.NewMetrics(reg)

	go RecordMetrics(*m)

	http.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))

	log.Printf("Listening on %v ...\n", LISTEN_ADDR)

	log.Fatal(http.ListenAndServe(LISTEN_ADDR, nil))
}

func RecordMetrics(m apps.Metrics) {
	// export the app-exporter version
	m.Version.With(prometheus.Labels{"version": VERSION}).Set(1)

	for {
		m.Reset()

		apps.Cubebackup(m)
		apps.Forgejo(m)
		apps.ForgejoRunner(m)
		apps.Grafana(m)
		apps.Minio(m)
		apps.Nextcloud(m)
		apps.Odoo(m)
		apps.Postgres(m)
		apps.Vaultwarden(m)

		log.Printf("> Waiting %v\n", INTERVAL)
		time.Sleep(INTERVAL)
	}
}