prometheus-fail2ban-exporter/src/exporter.go
Hector 5a107cc547 feat: support for textfile metrics (#13)
Add support for collecting arbitrary metrics from a textfile as well as
metrics collected from fail2ban. This allows other data to be exported
along with the fail2ban metrics (e.g. instance metadata).
Update the docker image to allow mounting a folder with a collection of
metric files to be exported. Only files ending in `.prom` with be read.
Update project README with the new functionality.
2021-10-12 20:38:26 +00:00

83 lines
1.9 KiB
Go

package main
import (
"fail2ban-prometheus-exporter/cfg"
"fail2ban-prometheus-exporter/export"
"fail2ban-prometheus-exporter/textfile"
"fmt"
"log"
"net/http"
_ "github.com/mattn/go-sqlite3"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
const (
metricsPath = "/metrics"
)
var (
version = "dev"
commit = "none"
date = "unknown"
builtBy = "unknown"
)
func printAppVersion() {
fmt.Println(version)
fmt.Printf(" build date: %s\r\n commit hash: %s\r\n built by: %s\r\n", date, commit, builtBy)
}
func rootHtmlHandler(w http.ResponseWriter, r *http.Request) {
_, err := w.Write([]byte(
`<html>
<head><title>Fail2Ban Exporter</title></head>
<body>
<h1>Fail2Ban Exporter</h1>
<p><a href="` + metricsPath + `">Metrics</a></p>
</body>
</html>`))
if err != nil {
log.Printf("error handling root url: %v", err)
w.WriteHeader(http.StatusInternalServerError)
}
}
func metricHandler(w http.ResponseWriter, r *http.Request, collector *textfile.Collector) {
promhttp.Handler().ServeHTTP(w, r)
collector.WriteTextFileMetrics(w, r)
}
func main() {
appSettings := cfg.Parse()
if appSettings.VersionMode {
printAppVersion()
} else {
addr := fmt.Sprintf("0.0.0.0:%d", appSettings.MetricsPort)
log.Printf("starting fail2ban exporter at %s", addr)
exporter := export.NewExporter(appSettings, version)
prometheus.MustRegister(exporter)
textFileCollector := textfile.NewCollector(appSettings)
prometheus.MustRegister(textFileCollector)
http.HandleFunc("/", rootHtmlHandler)
http.HandleFunc(metricsPath, func(w http.ResponseWriter, r *http.Request) {
metricHandler(w, r, textFileCollector)
})
log.Printf("metrics available at '%s'", metricsPath)
svrErr := make(chan error)
go func() {
svrErr <- http.ListenAndServe(addr, nil)
}()
log.Print("ready")
err := <-svrErr
log.Print(err)
}
}