postfix_exporter/main.go

73 lines
2.5 KiB
Go

package main
import (
"context"
"log"
"net/http"
"os"
"github.com/alecthomas/kingpin"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
func main() {
var (
app = kingpin.New("postfix_exporter", "Prometheus metrics exporter for postfix")
listenAddress = app.Flag("web.listen-address", "Address to listen on for web interface and telemetry.").Default(":9154").String()
metricsPath = app.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").String()
postfixShowqPath = app.Flag("postfix.showq_path", "Path at which Postfix places its showq socket.").Default("/var/spool/postfix/public/showq").String()
postfixLogfilePath = app.Flag("postfix.logfile_path", "Path where Postfix writes log entries.").Default("/var/log/maillog").String()
logUnsupportedLines = app.Flag("log.unsupported", "Log all unsupported lines.").Bool()
systemdEnable bool
systemdUnit, systemdSlice, systemdJournalPath string
)
systemdFlags(&systemdEnable, &systemdUnit, &systemdSlice, &systemdJournalPath, app)
kingpin.MustParse(app.Parse(os.Args[1:]))
var journal *Journal
if systemdEnable {
var err error
journal, err = NewJournal(systemdUnit, systemdSlice, systemdJournalPath)
if err != nil {
log.Fatalf("Error opening systemd journal: %s", err)
}
defer journal.Close()
log.Println("Reading log events from systemd")
} else {
log.Printf("Reading log events from %v", *postfixLogfilePath)
}
exporter, err := NewPostfixExporter(
*postfixShowqPath,
*postfixLogfilePath,
journal,
*logUnsupportedLines,
)
if err != nil {
log.Fatalf("Failed to create PostfixExporter: %s", err)
}
prometheus.MustRegister(exporter)
http.Handle(*metricsPath, promhttp.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
_, err = w.Write([]byte(`
<html>
<head><title>Postfix Exporter</title></head>
<body>
<h1>Postfix Exporter</h1>
<p><a href='` + *metricsPath + `'>Metrics</a></p>
</body>
</html>`))
if err != nil {
panic(err)
}
})
ctx, cancelFunc := context.WithCancel(context.Background())
defer cancelFunc()
go exporter.StartMetricCollection(ctx)
log.Print("Listening on ", *listenAddress)
log.Fatal(http.ListenAndServe(*listenAddress, nil))
}