From bacdc3c5871aef300800ef077258b22becd47a26 Mon Sep 17 00:00:00 2001
From: Marvin Vogt <git@srv6d.space>
Date: Fri, 5 May 2023 13:11:17 +0200
Subject: [PATCH 1/2] Allow explicitly including interfaces instead of only
 allowing excludes

---
 main.go                            | 19 +++++++++++++++----
 transceiver-collector/collector.go | 16 ++++++++++++++--
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/main.go b/main.go
index 87c7802..369332d 100644
--- a/main.go
+++ b/main.go
@@ -21,6 +21,7 @@ var (
 	metricsPath              = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics")
 	collectInterfaceFeatures = flag.Bool("collector.interface-features.enable", true, "Collect interface features")
 	excludeInterfaces        = flag.String("exclude.interfaces", "", "Comma seperated list of interfaces to exclude")
+	includeInterfaces        = flag.String("include.interfaces", "", "Comma seperated list of interfaces to include")
 	powerUnitdBm             = flag.Bool("collector.optical-power-in-dbm", false, "Report optical powers in dBm instead of mW (default false -> mW)")
 )
 
@@ -81,13 +82,23 @@ func (t transceiverCollectorWrapper) Describe(ch chan<- *prometheus.Desc) {
 }
 
 func handleMetricsRequest(w http.ResponseWriter, request *http.Request) {
+	var excludedIfaceNames []string
+	var includedIfaceNames []string
 	registry := prometheus.NewRegistry()
 
-	excludedIfaceNames := strings.Split(*excludeInterfaces, ",")
-	for index, excludedIfaceName := range excludedIfaceNames {
-		excludedIfaceNames[index] = strings.Trim(excludedIfaceName, " ")
+	if len(*excludeInterfaces) > 0 {
+		excludedIfaceNames = strings.Split(*excludeInterfaces, ",")
+		for index, excludedIfaceName := range excludedIfaceNames {
+			excludedIfaceNames[index] = strings.Trim(excludedIfaceName, " ")
+		}
+	}
+	if len(*includeInterfaces) > 0 {
+		includedIfaceNames = strings.Split(*includeInterfaces, ",")
+		for index, includedIfaceName := range includedIfaceNames {
+			includedIfaceNames[index] = strings.Trim(includedIfaceName, " ")
+		}
 	}
-	transceiverCollector := transceivercollector.NewCollector(excludedIfaceNames, *collectInterfaceFeatures, *powerUnitdBm)
+	transceiverCollector := transceivercollector.NewCollector(excludedIfaceNames, includedIfaceNames, *collectInterfaceFeatures, *powerUnitdBm)
 	wrapper := &transceiverCollectorWrapper{
 		collector: transceiverCollector,
 	}
diff --git a/transceiver-collector/collector.go b/transceiver-collector/collector.go
index f974317..29513ab 100644
--- a/transceiver-collector/collector.go
+++ b/transceiver-collector/collector.go
@@ -91,6 +91,7 @@ var laserLabels = []string{"interface", "laser_index"}
 // TransceiverCollector implements prometheus.Collector interface and collects various interface statistics
 type TransceiverCollector struct {
 	excludeInterfaces        []string
+	includeInterfaces        []string
 	collectInterfaceFeatures bool
 	powerUnitdBm             bool
 }
@@ -172,7 +173,7 @@ func init() {
 }
 
 // NewCollector initializes a new TransceiverCollector
-func NewCollector(excludeInterfaces []string, collectInterfaceFeatures bool, powerUnitdBm bool) *TransceiverCollector {
+func NewCollector(excludeInterfaces []string, includeInterfaces []string, collectInterfaceFeatures bool, powerUnitdBm bool) *TransceiverCollector {
 	laserTxPowerThresholdsSupportedDesc = prometheus.NewDesc(prefix+"laser_tx_power_supports_thresholds_bool", "1 if thresholds for the laser tx power are supported", laserLabels, nil)
 	laserRxPowerThresholdsSupportedDesc = prometheus.NewDesc(prefix+"laser_rx_power_supports_thresholds_bool", "1 if thresholds for the laser rx power are supported", laserLabels, nil)
 	if powerUnitdBm {
@@ -203,6 +204,7 @@ func NewCollector(excludeInterfaces []string, collectInterfaceFeatures bool, pow
 
 	return &TransceiverCollector{
 		excludeInterfaces:        excludeInterfaces,
+		includeInterfaces:        includeInterfaces,
 		collectInterfaceFeatures: collectInterfaceFeatures,
 		powerUnitdBm:             powerUnitdBm,
 	}
@@ -293,14 +295,24 @@ func (t *TransceiverCollector) getMonitoredInterfaces() ([]string, error) {
 		return []string{}, errors.Wrapf(err, "Could not enumerate system's interfaces")
 	}
 
+	InterfacesExcluded := len(t.excludeInterfaces) > 0
+	InterfacesIncluded := len(t.includeInterfaces) > 0
+	if InterfacesExcluded == true && InterfacesIncluded == true {
+		return []string{}, errors.New("Cannot include and exclude interfaces at the same time")
+	}
+
 	ifaceNames := []string{}
 	for _, iface := range interfaces {
 		if iface.Flags&net.FlagLoopback > 0 {
 			continue
 		}
-		if contains(t.excludeInterfaces, iface.Name) {
+		if InterfacesExcluded == true && contains(t.excludeInterfaces, iface.Name) {
 			continue
 		}
+		if InterfacesIncluded == true && !contains(t.includeInterfaces, iface.Name) {
+			continue
+		}
+
 		ifaceNames = append(ifaceNames, iface.Name)
 	}
 	return ifaceNames, nil

From 168de0b358bdcd871f106523326916ee1c4fad08 Mon Sep 17 00:00:00 2001
From: Marvin Vogt <git@srv6d.space>
Date: Fri, 5 May 2023 17:08:20 +0200
Subject: [PATCH 2/2] Mention option to explicitly include interfaces in README

---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index 87dce82..2819b97 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ Usage of ./transceiver-exporter:
     	Report optical powers in dBm instead of mW (default false -> mW)
   -exclude.interfaces string
     	Comma seperated list of interfaces to exclude
+  -include.interfaces string
+    	Comma seperated list of interfaces to include
   -version
     	Print version and exit
   -web.listen-address string