remove: database-based metrics

Remove all database-based metrics from the metrics endpoint.
Remove all code related to pulling metrics from the fail2ban database.
Remove all configuration variables related to the fail2ban database.
The CLI parameter for the database path was not removed to avoid breaking
compatibility.
Update docker entrypoint to remove references to the fail2ban database.
Remove all references to the old database metrics from the README.

src/collector/f2b/collector.go

@@ -2,14 +2,12 @@ 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
@@ -19,65 +17,39 @@ type Collector struct {
 }
 
 func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Collector {
-	colector := &Collector{
+	return &Collector{
+		socketPath:                 appSettings.Fail2BanSocketPath,
 		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 <- 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)
+	s, err := socket.ConnectToSocket(c.socketPath)
+	if err != nil {
+		log.Printf("error opening socket: %v", err)
+		c.socketConnectionErrorCount++
 	} else {
-		c.collectVersionMetric(ch, nil)
+		defer s.Close()
+	}
+
+	c.collectServerUpMetric(ch, s)
+	if err == nil && s != nil {
+		c.collectJailMetrics(ch, s)
+		c.collectVersionMetric(ch, s)
 	}
 	c.collectErrorCountMetric(ch)
 }