Merge branch 'add-metrics-on-basic-jail-configuration' into 'main'

Add metrics on basic jail configuration

See merge request hectorjsmith/fail2ban-prometheus-exporter!42

README.md

@@ -157,6 +157,9 @@ Exposed metrics:
 * `jail_banned_total` (per jail) - Total number of banned IPs since fail2ban startup (includes expired bans)
 * `jail_failed_current` (per jail) - Number of current failures
 * `jail_failed_total` (per jail) - Total number of failures since fail2ban startup
+* `jail_config_ban_time` (per jail) - How long an IP is banned for in this jail (in seconds)
+* `jail_config_find_time` (per jail) - How far back the filter will look for failures in this jail (in seconds)
+* `jail_config_max_retry` (per jail) - The max number of failures allowed before banning an IP in this jail
 * `version` - Version string of the exporter and fail2ban
 
 **Sample**
@@ -186,6 +189,18 @@ f2b_jail_failed_current{jail="sshd"} 6
 # TYPE f2b_jail_failed_total gauge
 f2b_jail_failed_total{jail="recidive"} 7
 f2b_jail_failed_total{jail="sshd"} 125
+# HELP f2b_config_jail_ban_time How long an IP is banned for in this jail (in seconds)
+# TYPE f2b_config_jail_ban_time gauge
+f2b_config_jail_ban_time{jail="recidive"} 604800
+f2b_config_jail_ban_time{jail="sshd"} 600
+# HELP f2b_config_jail_find_time How far back will the filter look for failures in this jail (in seconds)
+# TYPE f2b_config_jail_find_time gauge
+f2b_config_jail_find_time{jail="recidive"} 86400
+f2b_config_jail_find_time{jail="sshd"} 600
+# HELP f2b_config_jail_max_retries The number of failures allowed until the IP is banned by this jail
+# TYPE f2b_config_jail_max_retries gauge
+f2b_config_jail_max_retries{jail="recidive"} 5
+f2b_config_jail_max_retries{jail="sshd"} 5
 # HELP f2b_up Check if the fail2ban server is up
 # TYPE f2b_up gauge
 f2b_up 1

src/collector/f2b/socket.go

@@ -46,6 +46,21 @@ var (
 		"Total number of IPs banned by this jail (includes expired bans)",
 		[]string{"jail"}, nil,
 	)
+	metricJailBanTime = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_ban_time"),
+		"How long an IP is banned for in this jail (in seconds)",
+		[]string{"jail"}, nil,
+	)
+	metricJailFindTime = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_find_time"),
+		"How far back will the filter look for failures in this jail (in seconds)",
+		[]string{"jail"}, nil,
+	)
+	metricJailMaxRetry = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_max_retries"),
+		"The number of failures allowed until the IP is banned by this jail",
+		[]string{"jail"}, nil,
+	)
 	metricVersionInfo = prometheus.NewDesc(
 		prometheus.BuildFQName(namespace, "", "version"),
 		"Version of the exporter and fail2ban server",
@@ -98,6 +113,7 @@ func (c *Collector) collectJailMetrics(ch chan<- prometheus.Metric, s *socket.Fa
 
 	for i := range jails {
 		c.collectJailStatsMetric(ch, s, jails[i])
+		c.collectJailConfigMetrics(ch, s, jails[i])
 	}
 }
 
@@ -123,6 +139,36 @@ func (c *Collector) collectJailStatsMetric(ch chan<- prometheus.Metric, s *socke
 	)
 }
 
+func (c *Collector) collectJailConfigMetrics(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket, jail string) {
+	banTime, err := s.GetJailBanTime(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get ban time for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailBanTime, prometheus.GaugeValue, float64(banTime), jail,
+		)
+	}
+	findTime, err := s.GetJailFindTime(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get find time for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailFindTime, prometheus.GaugeValue, float64(findTime), jail,
+		)
+	}
+	maxRetry, err := s.GetJailMaxRetries(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get max retries for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailMaxRetry, prometheus.GaugeValue, float64(maxRetry), jail,
+		)
+	}
+}
+
 func (c *Collector) collectVersionMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
 	var err error
 	var fail2banVersion = ""

src/socket/fail2banSocket.go

@@ -118,6 +118,21 @@ func (s *Fail2BanSocket) GetJailStats(jail string) (JailStats, error) {
 	return stats, newBadFormatError(statusCommand, response)
 }
 
+func (s *Fail2BanSocket) GetJailBanTime(jail string) (int, error) {
+	command := fmt.Sprintf(banTimeCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
+func (s *Fail2BanSocket) GetJailFindTime(jail string) (int, error) {
+	command := fmt.Sprintf(findTimeCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
+func (s *Fail2BanSocket) GetJailMaxRetries(jail string) (int, error) {
+	command := fmt.Sprintf(maxRetriesCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
 func (s *Fail2BanSocket) GetServerVersion() (string, error) {
 	response, err := s.sendCommand([]string{versionCommand})
 	if err != nil {
@@ -132,6 +147,22 @@ func (s *Fail2BanSocket) GetServerVersion() (string, error) {
 	return "", newBadFormatError(versionCommand, response)
 }
 
+// sendSimpleIntCommand sends a command to the fail2ban socket and parses the response to extract an int.
+// This command assumes that the response data is in the format of `(d, d)` where `d` is a number.
+func (s *Fail2BanSocket) sendSimpleIntCommand(command string) (int, error) {
+	response, err := s.sendCommand(strings.Split(command, " "))
+	if err != nil {
+		return -1, err
+	}
+
+	if lvl1, ok := response.(*types.Tuple); ok {
+		if banTime, ok := lvl1.Get(1).(int); ok {
+			return banTime, nil
+		}
+	}
+	return -1, newBadFormatError(command, response)
+}
+
 func newBadFormatError(command string, data interface{}) error {
 	return fmt.Errorf("(%s) unexpected response format - cannot parse: %v", command, data)
 }

src/socket/protocol.go

@@ -12,6 +12,9 @@ const (
 	pingCommand          = "ping"
 	statusCommand        = "status"
 	versionCommand       = "version"
+	banTimeCommandFmt    = "get %s bantime"
+	findTimeCommandFmt   = "get %s findtime"
+	maxRetriesCommandFmt = "get %s maxretry"
 	socketReadBufferSize = 1024
 )