package main import ( "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promhttp" "log" "net/http" ) const namespace = "fail2ban" var up = prometheus.NewDesc( prometheus.BuildFQName(namespace, "", "up"), "Was the last fail2ban query successful.", nil, nil, ) type Exporter struct { } func (e *Exporter) Describe(ch chan<- *prometheus.Desc) { ch <- up } func (e *Exporter) Collect(ch chan<- prometheus.Metric) { ch <- prometheus.MustNewConstMetric( up, prometheus.GaugeValue, 1, ) } func main() { log.Print("starting fail2ban exporter") exporter := &Exporter{} prometheus.MustRegister(exporter) http.Handle("/metrics", promhttp.Handler()) log.Fatal(http.ListenAndServe(":9101", nil)) }