netdev_common: Add ifAlias label

Author: tomvil

collector/netdev_common.go

@@ -21,7 +21,9 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"os"
 	"strconv"
+	"strings"
 	"sync"
 
 	"github.com/alecthomas/kingpin/v2"
@@ -37,6 +39,7 @@ var (
 	oldNetdevDeviceExclude = kingpin.Flag("collector.netdev.device-blacklist", "DEPRECATED: Use collector.netdev.device-exclude").Hidden().String()
 	netdevAddressInfo      = kingpin.Flag("collector.netdev.address-info", "Collect address-info for every device").Bool()
 	netdevDetailedMetrics  = kingpin.Flag("collector.netdev.enable-detailed-metrics", "Use (incompatible) metric names that provide more detailed stats on Linux").Bool()
+	netdevLabelIfAlias     = kingpin.Flag("collector.netdev.label-ifalias", "Add ifAlias label").Bool()
 )
 
 type netDevCollector struct {
@@ -98,10 +101,15 @@ func (c *netDevCollector) metricDesc(key string) *prometheus.Desc {
 	defer c.metricDescsMutex.Unlock()
 
 	if _, ok := c.metricDescs[key]; !ok {
+		labels := []string{"device"}
+		if *netdevLabelIfAlias {
+			labels = append(labels, "ifalias")
+		}
+
 		c.metricDescs[key] = prometheus.NewDesc(
 			prometheus.BuildFQName(namespace, c.subsystem, key+"_total"),
 			fmt.Sprintf("Network device statistic %s.", key),
-			[]string{"device"},
+			labels,
 			nil,
 		)
 	}
@@ -120,7 +128,13 @@ func (c *netDevCollector) Update(ch chan<- prometheus.Metric) error {
 		}
 		for key, value := range devStats {
 			desc := c.metricDesc(key)
-			ch <- prometheus.MustNewConstMetric(desc, prometheus.CounterValue, float64(value), dev)
+
+			labelValues := []string{dev}
+			if *netdevLabelIfAlias {
+				labelValues = append(labelValues, getIfAlias(dev))
+			}
+
+			ch <- prometheus.MustNewConstMetric(desc, prometheus.CounterValue, float64(value), labelValues...)
 		}
 	}
 	if *netdevAddressInfo {
@@ -239,3 +253,13 @@ func popz(m map[string]uint64, key string) uint64 {
 	}
 	return 0
 }
+
+func getIfAlias(dev string) string {
+	IfAliasPath := fmt.Sprintf("/sys/class/net/%s/ifalias", dev)
+	IfAliasBytes, err := os.ReadFile(IfAliasPath)
+	if err != nil {
+		return ""
+	}
+
+	return strings.TrimSpace(string(IfAliasBytes))
+}