From f65453d24fb7758f604c9752e95c0a3a50517c2a Mon Sep 17 00:00:00 2001
From: Jakob Gastinger <jgastinger@anexia-it.com>
Date: Wed, 20 Dec 2023 17:23:21 +0100
Subject: [PATCH] now scrapes interface information to include underlying
 interfaces for each subscriber

---
 pkg/features/subscriber/collector.go | 57 ++++++++++++++++++++++++++--
 pkg/features/subscriber/rpc.go       | 22 ++++++++---
 2 files changed, 69 insertions(+), 10 deletions(-)

diff --git a/pkg/features/subscriber/collector.go b/pkg/features/subscriber/collector.go
index c8c104b2..10c5a868 100644
--- a/pkg/features/subscriber/collector.go
+++ b/pkg/features/subscriber/collector.go
@@ -3,6 +3,10 @@
 package subscriber
 
 import (
+	"errors"
+	"fmt"
+	"strings"
+
 	"github.com/czerwonk/junos_exporter/pkg/collector"
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -12,7 +16,7 @@ const prefix string = "junos_subscriber_info"
 var subscriberInfo *prometheus.Desc
 
 func init() {
-	l := []string{"target", "interface", "agent_circuit_id", "agent_remote_id"}
+	l := []string{"target", "interface", "agent_circuit_id", "agent_remote_id", "underlying_ifd"}
 	subscriberInfo = prometheus.NewDesc(prefix+"", "Subscriber Detail", l, nil)
 }
 
@@ -33,16 +37,61 @@ func (*subcsribers_information) Describe(ch chan<- *prometheus.Desc) {
 
 // Collect collects metrics from JunOS
 func (c *subcsribers_information) Collect(client collector.Client, ch chan<- prometheus.Metric, labelValues []string) error {
+
 	var x = subcsribers_information{}
-	err := client.RunCommandAndParse("show subscribers client-type dhcp detail", &x)
+	err := client.RunCommandAndParse("show subscribers client-type dhcp detail", &x) //TODO: see if client-type dhcp can be left out
+	if err != nil {
+		return err
+	}
+
+	logicalInterfaceMap, err := getLogicalInterfaceInformation(client)
 	if err != nil {
 		return err
 	}
 
 	for _, subscriber := range x.SubscribersInformation.Subscriber {
-		labels := append(labelValues, subscriber.Interface, subscriber.AgentCircuitId, subscriber.AgentRemoteId)
+		underlying_interface, err := findUnderlyingInterface(client, subscriber.UnderlyingInterface, logicalInterfaceMap, 2)
+		if err != nil {
+			fmt.Println(err)
+		}
+
+		labels := append(labelValues, subscriber.Interface, subscriber.AgentCircuitId, subscriber.AgentRemoteId, underlying_interface)
 		ch <- prometheus.MustNewConstMetric(subscriberInfo, prometheus.CounterValue, 1, labels...)
 	}
-
 	return nil
 }
+
+func getLogicalInterfaceInformation(client collector.Client) (map[string]string, error) {
+
+	var interfaceInformation = &InterfaceInformation{}
+	var interfaceMap = make(map[string]string)
+
+	err := client.RunCommandAndParse("show interfaces demux0 brief", interfaceInformation)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, logicalInterface := range interfaceInformation.LogicalInterfaces {
+		interfaceMap[logicalInterface.Name] = logicalInterface.DemuxUnderlyingIfName
+	}
+
+	return interfaceMap, nil
+}
+
+func findUnderlyingInterface(client collector.Client, ifName string, logicalIfMap map[string]string, maxDepth int) (string, error) {
+
+	if !(strings.HasPrefix(ifName, "demux")) {
+		return ifName, nil
+	}
+
+	if maxDepth < 0 {
+		return "", errors.New("no underlying interface found, max treshold reached")
+	}
+
+	logicalIfName, exists := logicalIfMap[ifName]
+	if !exists {
+		return "", errors.New("no underlying interface found")
+	}
+
+	return findUnderlyingInterface(client, logicalIfName, logicalIfMap, maxDepth-1)
+}
diff --git a/pkg/features/subscriber/rpc.go b/pkg/features/subscriber/rpc.go
index 8fb028b1..3b8f359e 100644
--- a/pkg/features/subscriber/rpc.go
+++ b/pkg/features/subscriber/rpc.go
@@ -2,13 +2,23 @@ package subscriber
 
 type subcsribers_information struct {
 	SubscribersInformation struct {
-		Subscriber []subscriber `xml:"subscriber"`
+		Subscriber []Subscriber `xml:"subscriber"`
 	} `xml:"subscribers-information"`
 }
 
-type subscriber struct {
-	AccessType     string `xml:"access-type"`
-	Interface      string `xml:"interface"`
-	AgentCircuitId string `xml:"agent-circuit-id"`
-	AgentRemoteId  string `xml:"agent-remote-id"`
+type Subscriber struct {
+	AccessType          string `xml:"access-type"`
+	Interface           string `xml:"interface"`
+	AgentCircuitId      string `xml:"agent-circuit-id"`
+	AgentRemoteId       string `xml:"agent-remote-id"`
+	UnderlyingInterface string `xml:"underlying-interface"`
+}
+
+type InterfaceInformation struct {
+	LogicalInterfaces []LogicalInterface `xml:"interface-information>physical-interface>logical-interface"`
+}
+
+type LogicalInterface struct {
+	Name                  string `xml:"name"`
+	DemuxUnderlyingIfName string `xml:"demux-information>demux-interface>demux-underlying-interface-name"`
 }