refactor: create new collector folder

Create a new `collector` folder to store the code for the different
collectors. Move the existing f2b and textfile collectors to this folder.
Minor refactors to the f2b collector to better match the code style of the
newer textfile collector.

src/collector/f2b/collector.go

@@ -0,0 +1,83 @@
+package f2b
+
+import (
+	"fail2ban-prometheus-exporter/cfg"
+	fail2banDb "fail2ban-prometheus-exporter/db"
+	"fail2ban-prometheus-exporter/socket"
+	"github.com/prometheus/client_golang/prometheus"
+	"log"
+)
+
+type Collector struct {
+	db                         *fail2banDb.Fail2BanDB
+	socketPath                 string
+	exporterVersion            string
+	lastError                  error
+	dbErrorCount               int
+	socketConnectionErrorCount int
+	socketRequestErrorCount    int
+}
+
+func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Collector {
+	colector := &Collector{
+		exporterVersion:            exporterVersion,
+		lastError:                  nil,
+		dbErrorCount:               0,
+		socketConnectionErrorCount: 0,
+		socketRequestErrorCount:    0,
+	}
+	if appSettings.Fail2BanDbPath != "" {
+		log.Print("database-based metrics have been deprecated and will be removed in a future release")
+		colector.db = fail2banDb.MustConnectToDb(appSettings.Fail2BanDbPath)
+	}
+	if appSettings.Fail2BanSocketPath != "" {
+		colector.socketPath = appSettings.Fail2BanSocketPath
+	}
+	return colector
+}
+
+func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+	if c.db != nil {
+		ch <- deprecatedMetricUp
+		ch <- deprecatedMetricBadIpsPerJail
+		ch <- deprecatedMetricBannedIpsPerJail
+		ch <- deprecatedMetricEnabledJails
+		ch <- deprecatedMetricErrorCount
+	}
+	if c.socketPath != "" {
+		ch <- metricServerUp
+		ch <- metricJailCount
+		ch <- metricJailFailedCurrent
+		ch <- metricJailFailedTotal
+		ch <- metricJailBannedCurrent
+		ch <- metricJailBannedTotal
+	}
+	ch <- metricErrorCount
+}
+
+func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+	if c.db != nil {
+		c.collectDeprecatedBadIpsPerJailMetrics(ch)
+		c.collectDeprecatedBannedIpsPerJailMetrics(ch)
+		c.collectDeprecatedEnabledJailMetrics(ch)
+		c.collectDeprecatedUpMetric(ch)
+		c.collectDeprecatedErrorCountMetric(ch)
+	}
+	if c.socketPath != "" {
+		s, err := socket.ConnectToSocket(c.socketPath)
+		if err != nil {
+			log.Printf("error opening socket: %v", err)
+			c.socketConnectionErrorCount++
+		} else {
+			defer s.Close()
+		}
+		c.collectServerUpMetric(ch, s)
+		if err == nil && s != nil {
+			c.collectJailMetrics(ch, s)
+		}
+		c.collectVersionMetric(ch, s)
+	} else {
+		c.collectVersionMetric(ch, nil)
+	}
+	c.collectErrorCountMetric(ch)
+}

src/collector/f2b/database.go

@@ -1,4 +1,4 @@
-package export
+package f2b
 
 import (
 	"github.com/prometheus/client_golang/prometheus"
@@ -37,9 +37,9 @@ var (
 	)
 )
 
-func (e *Exporter) collectDeprecatedUpMetric(ch chan<- prometheus.Metric) {
+func (c *Collector) collectDeprecatedUpMetric(ch chan<- prometheus.Metric) {
 	var upMetricValue float64 = 1
-	if e.lastError != nil {
+	if c.lastError != nil {
 		upMetricValue = 0
 	}
 	ch <- prometheus.MustNewConstMetric(
@@ -47,18 +47,18 @@ func (e *Exporter) collectDeprecatedUpMetric(ch chan<- prometheus.Metric) {
 	)
 }
 
-func (e *Exporter) collectDeprecatedErrorCountMetric(ch chan<- prometheus.Metric) {
+func (c *Collector) collectDeprecatedErrorCountMetric(ch chan<- prometheus.Metric) {
 	ch <- prometheus.MustNewConstMetric(
-		deprecatedMetricErrorCount, prometheus.CounterValue, float64(e.dbErrorCount), "db",
+		deprecatedMetricErrorCount, prometheus.CounterValue, float64(c.dbErrorCount), "db",
 	)
 }
 
-func (e *Exporter) collectDeprecatedBadIpsPerJailMetrics(ch chan<- prometheus.Metric) {
+func (c *Collector) collectDeprecatedBadIpsPerJailMetrics(ch chan<- prometheus.Metric) {
-	jailNameToCountMap, err := e.db.CountBadIpsPerJail()
+	jailNameToCountMap, err := c.db.CountBadIpsPerJail()
-	e.lastError = err
+	c.lastError = err
 
 	if err != nil {
-		e.dbErrorCount++
+		c.dbErrorCount++
 		log.Print(err)
 	}
 
@@ -69,12 +69,12 @@ func (e *Exporter) collectDeprecatedBadIpsPerJailMetrics(ch chan<- prometheus.Me
 	}
 }
 
-func (e *Exporter) collectDeprecatedBannedIpsPerJailMetrics(ch chan<- prometheus.Metric) {
+func (c *Collector) collectDeprecatedBannedIpsPerJailMetrics(ch chan<- prometheus.Metric) {
-	jailNameToCountMap, err := e.db.CountBannedIpsPerJail()
+	jailNameToCountMap, err := c.db.CountBannedIpsPerJail()
-	e.lastError = err
+	c.lastError = err
 
 	if err != nil {
-		e.dbErrorCount++
+		c.dbErrorCount++
 		log.Print(err)
 	}
 
@@ -85,12 +85,12 @@ func (e *Exporter) collectDeprecatedBannedIpsPerJailMetrics(ch chan<- prometheus
 	}
 }
 
-func (e *Exporter) collectDeprecatedEnabledJailMetrics(ch chan<- prometheus.Metric) {
+func (c *Collector) collectDeprecatedEnabledJailMetrics(ch chan<- prometheus.Metric) {
-	jailNameToEnabledMap, err := e.db.JailNameToEnabledValue()
+	jailNameToEnabledMap, err := c.db.JailNameToEnabledValue()
-	e.lastError = err
+	c.lastError = err
 
 	if err != nil {
-		e.dbErrorCount++
+		c.dbErrorCount++
 		log.Print(err)
 	}
 

src/collector/f2b/socket.go

@@ -1,4 +1,4 @@
-package export
+package f2b
 
 import (
 	"fail2ban-prometheus-exporter/socket"
@@ -53,24 +53,24 @@ var (
 	)
 )
 
-func (e *Exporter) collectErrorCountMetric(ch chan<- prometheus.Metric) {
+func (c *Collector) collectErrorCountMetric(ch chan<- prometheus.Metric) {
 	ch <- prometheus.MustNewConstMetric(
-		metricErrorCount, prometheus.CounterValue, float64(e.dbErrorCount), "db",
+		metricErrorCount, prometheus.CounterValue, float64(c.dbErrorCount), "db",
 	)
 	ch <- prometheus.MustNewConstMetric(
-		metricErrorCount, prometheus.CounterValue, float64(e.socketConnectionErrorCount), "socket_conn",
+		metricErrorCount, prometheus.CounterValue, float64(c.socketConnectionErrorCount), "socket_conn",
 	)
 	ch <- prometheus.MustNewConstMetric(
-		metricErrorCount, prometheus.CounterValue, float64(e.socketRequestErrorCount), "socket_req",
+		metricErrorCount, prometheus.CounterValue, float64(c.socketRequestErrorCount), "socket_req",
 	)
 }
 
-func (e *Exporter) collectServerUpMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+func (c *Collector) collectServerUpMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
 	var serverUp float64 = 0
 	if s != nil {
 		pingSuccess, err := s.Ping()
 		if err != nil {
-			e.socketRequestErrorCount++
+			c.socketRequestErrorCount++
 			log.Print(err)
 		}
 		if err == nil && pingSuccess {
@@ -82,11 +82,11 @@ func (e *Exporter) collectServerUpMetric(ch chan<- prometheus.Metric, s *socket.
 	)
 }
 
-func (e *Exporter) collectJailMetrics(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+func (c *Collector) collectJailMetrics(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
 	jails, err := s.GetJails()
 	var count float64 = 0
 	if err != nil {
-		e.socketRequestErrorCount++
+		c.socketRequestErrorCount++
 		log.Print(err)
 	}
 	if err == nil {
@@ -97,14 +97,14 @@ func (e *Exporter) collectJailMetrics(ch chan<- prometheus.Metric, s *socket.Fai
 	)
 
 	for i := range jails {
-		e.collectJailStatsMetric(ch, s, jails[i])
+		c.collectJailStatsMetric(ch, s, jails[i])
 	}
 }
 
-func (e *Exporter) collectJailStatsMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket, jail string) {
+func (c *Collector) collectJailStatsMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket, jail string) {
 	stats, err := s.GetJailStats(jail)
 	if err != nil {
-		e.socketRequestErrorCount++
+		c.socketRequestErrorCount++
 		log.Printf("failed to get stats for jail %s: %v", jail, err)
 		return
 	}
@@ -123,18 +123,18 @@ func (e *Exporter) collectJailStatsMetric(ch chan<- prometheus.Metric, s *socket
 	)
 }
 
-func (e *Exporter) collectVersionMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+func (c *Collector) collectVersionMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
 	var err error
 	var fail2banVersion = ""
 	if s != nil {
 		fail2banVersion, err = s.GetServerVersion()
 		if err != nil {
-			e.socketRequestErrorCount++
+			c.socketRequestErrorCount++
 			log.Printf("failed to get fail2ban server version: %v", err)
 		}
 	}
 
 	ch <- prometheus.MustNewConstMetric(
-		metricVersionInfo, prometheus.GaugeValue, float64(1), e.exporterVersion, fail2banVersion,
+		metricVersionInfo, prometheus.GaugeValue, float64(1), c.exporterVersion, fail2banVersion,
 	)
 }

src/export/build.go

@@ -1,25 +0,0 @@
-package export
-
-import (
-	"fail2ban-prometheus-exporter/cfg"
-	fail2banDb "fail2ban-prometheus-exporter/db"
-	"log"
-)
-
-func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Exporter {
-	exporter := &Exporter{
-		exporterVersion:            exporterVersion,
-		lastError:                  nil,
-		dbErrorCount:               0,
-		socketConnectionErrorCount: 0,
-		socketRequestErrorCount:    0,
-	}
-	if appSettings.Fail2BanDbPath != "" {
-		log.Print("database-based metrics have been deprecated and will be removed in a future release")
-		exporter.db = fail2banDb.MustConnectToDb(appSettings.Fail2BanDbPath)
-	}
-	if appSettings.Fail2BanSocketPath != "" {
-		exporter.socketPath = appSettings.Fail2BanSocketPath
-	}
-	return exporter
-}

src/export/exporter.go

@@ -1,64 +0,0 @@
-package export
-
-import (
-	fail2banDb "fail2ban-prometheus-exporter/db"
-	"fail2ban-prometheus-exporter/socket"
-	"github.com/prometheus/client_golang/prometheus"
-	"log"
-)
-
-type Exporter struct {
-	db                         *fail2banDb.Fail2BanDB
-	socketPath                 string
-	exporterVersion            string
-	lastError                  error
-	dbErrorCount               int
-	socketConnectionErrorCount int
-	socketRequestErrorCount    int
-}
-
-func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
-	if e.db != nil {
-		ch <- deprecatedMetricUp
-		ch <- deprecatedMetricBadIpsPerJail
-		ch <- deprecatedMetricBannedIpsPerJail
-		ch <- deprecatedMetricEnabledJails
-		ch <- deprecatedMetricErrorCount
-	}
-	if e.socketPath != "" {
-		ch <- metricServerUp
-		ch <- metricJailCount
-		ch <- metricJailFailedCurrent
-		ch <- metricJailFailedTotal
-		ch <- metricJailBannedCurrent
-		ch <- metricJailBannedTotal
-	}
-	ch <- metricErrorCount
-}
-
-func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
-	if e.db != nil {
-		e.collectDeprecatedBadIpsPerJailMetrics(ch)
-		e.collectDeprecatedBannedIpsPerJailMetrics(ch)
-		e.collectDeprecatedEnabledJailMetrics(ch)
-		e.collectDeprecatedUpMetric(ch)
-		e.collectDeprecatedErrorCountMetric(ch)
-	}
-	if e.socketPath != "" {
-		s, err := socket.ConnectToSocket(e.socketPath)
-		if err != nil {
-			log.Printf("error opening socket: %v", err)
-			e.socketConnectionErrorCount++
-		} else {
-			defer s.Close()
-		}
-		e.collectServerUpMetric(ch, s)
-		if err == nil && s != nil {
-			e.collectJailMetrics(ch, s)
-		}
-		e.collectVersionMetric(ch, s)
-	} else {
-		e.collectVersionMetric(ch, nil)
-	}
-	e.collectErrorCountMetric(ch)
-}

src/exporter.go

@@ -2,8 +2,8 @@ package main
 
 import (
 	"fail2ban-prometheus-exporter/cfg"
-	"fail2ban-prometheus-exporter/export"
+	"fail2ban-prometheus-exporter/collector/f2b"
-	"fail2ban-prometheus-exporter/textfile"
+	textfile2 "fail2ban-prometheus-exporter/collector/textfile"
 	"fmt"
 	"log"
 	"net/http"
@@ -44,7 +44,7 @@ func rootHtmlHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func metricHandler(w http.ResponseWriter, r *http.Request, collector *textfile.Collector) {
+func metricHandler(w http.ResponseWriter, r *http.Request, collector *textfile2.Collector) {
 	promhttp.Handler().ServeHTTP(w, r)
 	collector.WriteTextFileMetrics(w, r)
 }
@@ -58,10 +58,10 @@ func main() {
 
 		log.Printf("starting fail2ban exporter at %s", addr)
 
-		exporter := export.NewExporter(appSettings, version)
+		f2bCollector := f2b.NewExporter(appSettings, version)
-		prometheus.MustRegister(exporter)
+		prometheus.MustRegister(f2bCollector)
 
-		textFileCollector := textfile.NewCollector(appSettings)
+		textFileCollector := textfile2.NewCollector(appSettings)
 		prometheus.MustRegister(textFileCollector)
 
 		http.HandleFunc("/", rootHtmlHandler)