Fixed double metric labels.

examples/server2.status

@@ -6,11 +6,13 @@ CLIENT_LIST,redacted2,0.0.0.0:60536,0.0.0.0,2925752,3145665,Thu Mar 16 17:08:57
 CLIENT_LIST,redacted3,0.0.0.0:28331,0.0.0.0,57316467,611736741,Thu Mar 16 17:08:57 2017,1489680537,UNDEF
 CLIENT_LIST,redacted4,0.0.0.0:52335,0.0.0.0,24289622392,70914674697,Fri Mar 17 11:16:29 2017,1489745789,UNDEF
 CLIENT_LIST,redacted5,0.0.0.0:51865,0.0.0.0,277017840,1544465106,Thu Mar 16 17:09:01 2017,1489680541,UNDEF
+CLIENT_LIST,redacted1,0.0.0.0:19021,0.0.0.0,693438277,228390856,Thu Mar 16 17:09:03 2017,1489680543,UNDEF
 HEADER,ROUTING_TABLE,Virtual Address,Common Name,Real Address,Last Ref,Last Ref (time_t)
 ROUTING_TABLE,0.0.0.0,redacted1,0.0.0.0:19021,Tue Mar 21 10:26:48 2017,1490088408
 ROUTING_TABLE,0.0.0.0,redacted5,0.0.0.0:51865,Tue Mar 21 10:38:26 2017,1490089106
 ROUTING_TABLE,0.0.0.0,redacted3,0.0.0.0:28331,Tue Mar 21 10:39:06 2017,1490089146
 ROUTING_TABLE,0.0.0.0,redacted4,0.0.0.0:52335,Tue Mar 21 10:39:13 2017,1490089153
 ROUTING_TABLE,0.0.0.0,redacted2,0.0.0.0:60536,Thu Mar 16 17:08:58 2017,1489680538
+ROUTING_TABLE,0.0.0.0,redacted1,0.0.0.0:19021,Tue Mar 21 10:26:48 2017,1490088408
 GLOBAL_STATS,Max bcast/mcast queue length,0
 END

exporters/openvpn_exporter.go

@@ -184,6 +184,8 @@ func (e *OpenVPNExporter) collectServerStatusFromReader(statusPath string, file
 	// counter of connected client
 	numberConnectedClient := 0
 
+	recordedMetrics := map[OpenvpnServerHeaderField][]string{}
+
 	for scanner.Scan() {
 		fields := strings.Split(scanner.Text(), separator)
 		if fields[0] == "END" && len(fields) == 1 {
@@ -237,6 +239,7 @@ func (e *OpenVPNExporter) collectServerStatusFromReader(statusPath string, file
 			// Export relevant columns as individual metrics.
 			for _, metric := range header.Metrics {
 				if columnValue, ok := columnValues[metric.Column]; ok {
+					if l, _ := recordedMetrics[metric]; ! subslice(labels, l) {
 						value, err := strconv.ParseFloat(columnValue, 64)
 						if err != nil {
 							return err
@@ -246,6 +249,10 @@ func (e *OpenVPNExporter) collectServerStatusFromReader(statusPath string, file
 							metric.ValueType,
 							value,
 							labels...)
+						recordedMetrics[metric] = append(recordedMetrics[metric], labels...)
+					} else {
+						log.Printf("Metric entry with same labels: %s, %s", metric.Column, labels)
+					}
 				}
 			}
 		} else {
@@ -261,6 +268,27 @@ func (e *OpenVPNExporter) collectServerStatusFromReader(statusPath string, file
 	return scanner.Err()
 }
 
+// Does slice contain string
+func contains(s []string, e string) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}
+
+// Is a sub-slice of slice
+func subslice(sub []string, main []string) bool {
+	if len(sub) > len(main) {return false}
+	for _, s := range sub {
+		if ! contains(main, s) {
+			return false
+		}
+	}
+	return true
+}
+
 // Converts OpenVPN client status information into Prometheus metrics.
 func (e *OpenVPNExporter) collectClientStatusFromReader(statusPath string, file io.Reader, ch chan<- prometheus.Metric) error {
 	scanner := bufio.NewScanner(file)