fail2ban-prometheus-exporter/exporter.go
Hector 4f18bf35a8 feat: add cli parameters for db path and metrics port (#4)
Add support for configuring CLI parameters in the application using a new
`cfg` package. The `cfg` package exports an `AppSettings` struct that
contains the settings the application was run with.
Update the application to use the new CLI parameters to set the db to open
and the port to use for the metrics server.
Add support for setting the app version during build. The app includes a
`-version` flag to print the stored version data.
2021-02-06 15:17:35 +00:00

103 lines
2.5 KiB
Go

package main
import (
"fail2ban-prometheus-exporter/cfg"
fail2banDb "fail2ban-prometheus-exporter/db"
"fmt"
_ "github.com/mattn/go-sqlite3"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"log"
"net/http"
)
const namespace = "fail2ban"
var (
version = "dev"
commit = "none"
date = "unknown"
builtBy = "unknown"
metricUp = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "up"),
"Was the last fail2ban query successful.",
nil, nil,
)
metricBannedIpsPerJail = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "banned_ips"),
"Number of banned IPs stored in the database (per jail).",
[]string{"jail"}, nil,
)
metricBadIpsPerJail = prometheus.NewDesc(
prometheus.BuildFQName(namespace, "", "bad_ips"),
"Number of bad IPs stored in the database (per jail).",
[]string{"jail"}, nil,
)
)
type Exporter struct {
db *fail2banDb.Fail2BanDB
}
func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
ch <- metricUp
ch <- metricBadIpsPerJail
ch <- metricBannedIpsPerJail
}
func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
ch <- prometheus.MustNewConstMetric(
metricUp, prometheus.GaugeValue, 1,
)
e.collectBadIpsPerJailMetrics(ch)
e.collectBannedIpsPerJailMetrics(ch)
}
func (e *Exporter) collectBadIpsPerJailMetrics(ch chan<- prometheus.Metric) {
jailNameToCountMap, err := e.db.CountBadIpsPerJail()
if err != nil {
log.Print(err)
}
for jailName, count := range jailNameToCountMap {
ch <- prometheus.MustNewConstMetric(
metricBadIpsPerJail, prometheus.GaugeValue, float64(count), jailName,
)
}
}
func (e *Exporter) collectBannedIpsPerJailMetrics(ch chan<- prometheus.Metric) {
jailNameToCountMap, err := e.db.CountBannedIpsPerJail()
if err != nil {
log.Print(err)
}
for jailName, count := range jailNameToCountMap {
ch <- prometheus.MustNewConstMetric(
metricBannedIpsPerJail, prometheus.GaugeValue, float64(count), jailName,
)
}
}
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 main() {
appSettings := cfg.Parse()
if appSettings.VersionMode {
printAppVersion()
} else {
log.Print("starting fail2ban exporter")
exporter := &Exporter{
db: fail2banDb.MustConnectToDb(appSettings.Fail2BanDbPath),
}
prometheus.MustRegister(exporter)
http.Handle("/metrics", promhttp.Handler())
log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", appSettings.MetricsPort), nil))
}
}