Initial Commit

collector/f2b/collector.go

@@ -0,0 +1,76 @@
+package f2b
+
+import (
+	"log"
+	"os"
+
+	"git.cryptic.systems/volker.raschek/prometheus-fail2ban-exporter/cfg"
+	"git.cryptic.systems/volker.raschek/prometheus-fail2ban-exporter/socket"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type Collector struct {
+	socketPath                 string
+	exporterVersion            string
+	lastError                  error
+	socketConnectionErrorCount int
+	socketRequestErrorCount    int
+	exitOnSocketConnError      bool
+}
+
+func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Collector {
+	log.Printf("reading fail2ban metrics from socket file: %s", appSettings.Fail2BanSocketPath)
+	printFail2BanServerVersion(appSettings.Fail2BanSocketPath)
+	return &Collector{
+		socketPath:                 appSettings.Fail2BanSocketPath,
+		exporterVersion:            exporterVersion,
+		lastError:                  nil,
+		socketConnectionErrorCount: 0,
+		socketRequestErrorCount:    0,
+		exitOnSocketConnError:      appSettings.ExitOnSocketConnError,
+	}
+}
+
+func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- metricServerUp
+	ch <- metricJailCount
+	ch <- metricJailFailedCurrent
+	ch <- metricJailFailedTotal
+	ch <- metricJailBannedCurrent
+	ch <- metricJailBannedTotal
+	ch <- metricErrorCount
+}
+
+func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+	s, err := socket.ConnectToSocket(c.socketPath)
+	if err != nil {
+		log.Printf("error opening socket: %v", err)
+		c.socketConnectionErrorCount++
+		if c.exitOnSocketConnError {
+			os.Exit(1)
+		}
+	} else {
+		defer s.Close()
+	}
+
+	c.collectServerUpMetric(ch, s)
+	if err == nil && s != nil {
+		c.collectJailMetrics(ch, s)
+		c.collectVersionMetric(ch, s)
+	}
+	c.collectErrorCountMetric(ch)
+}
+
+func printFail2BanServerVersion(socketPath string) {
+	s, err := socket.ConnectToSocket(socketPath)
+	if err != nil {
+		log.Printf("error connecting to socket: %v", err)
+	} else {
+		version, err := s.GetServerVersion()
+		if err != nil {
+			log.Printf("error interacting with socket: %v", err)
+		} else {
+			log.Printf("successfully connected to fail2ban socket! fail2ban version: %s", version)
+		}
+	}
+}