add --log-nodes flag for comprehensive node logging

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/tendrils/main.go

@@ -12,6 +12,7 @@ func main() {
 	noLLDP := flag.Bool("no-lldp", false, "disable LLDP discovery")
 	noSNMP := flag.Bool("no-snmp", false, "disable SNMP discovery")
 	logEvents := flag.Bool("log-events", false, "log node events")
+	logNodes := flag.Bool("log-nodes", false, "log full node details on changes")
 	debugARP := flag.Bool("debug-arp", false, "debug ARP discovery")
 	debugLLDP := flag.Bool("debug-lldp", false, "debug LLDP discovery")
 	debugSNMP := flag.Bool("debug-snmp", false, "debug SNMP discovery")
@@ -23,6 +24,7 @@ func main() {
 	t.DisableLLDP = *noLLDP
 	t.DisableSNMP = *noSNMP
 	t.LogEvents = *logEvents
+	t.LogNodes = *logNodes
 	t.DebugARP = *debugARP
 	t.DebugLLDP = *debugLLDP
 	t.DebugSNMP = *debugSNMP

nodes.go

@@ -15,21 +15,26 @@ type Interface struct {
 }
 
 func (i *Interface) String() string {
-	name := i.Name
-	if name == "" {
-		name = "??"
-	}
-
 	var ips []string
 	for _, ip := range i.IPs {
 		ips = append(ips, ip.String())
 	}
 	sort.Strings(ips)
 
-	if len(ips) == 0 {
+	var parts []string
-		return fmt.Sprintf("%s/%s", name, i.MAC)
+	parts = append(parts, i.MAC.String())
+	if i.Name != "" {
+		parts = append(parts, fmt.Sprintf("(%s)", i.Name))
 	}
-	return fmt.Sprintf("%s/%s %v", name, i.MAC, ips)
+	if len(ips) > 0 {
+		parts = append(parts, fmt.Sprintf("%v", ips))
+	}
+
+	result := parts[0]
+	for _, p := range parts[1:] {
+		result += " " + p
+	}
+	return result
 }
 
 type Node struct {
@@ -131,13 +136,18 @@ func (n *Nodes) Update(mac net.HardwareAddr, ips []net.IP, ifaceName, nodeName,
 		node.Name = nodeName
 	}
 
-	if len(added) > 0 && n.t.LogEvents {
+	if len(added) > 0 {
+		if n.t.LogEvents {
 			if isNew {
 				log.Printf("[add] %s %v (via %s)", node, added, source)
 			} else {
 				log.Printf("[update] %s +%v (via %s)", node, added, source)
 			}
 		}
+		if n.t.LogNodes {
+			n.logNode(node)
+		}
+	}
 }
 
 func (n *Nodes) Merge(macs []net.HardwareAddr, source string) {
@@ -172,6 +182,10 @@ func (n *Nodes) Merge(macs []net.HardwareAddr, source string) {
 		}
 		n.mergeNodes(targetID, ids[i])
 	}
+
+	if n.t.LogNodes {
+		n.logNode(n.nodes[targetID])
+	}
 }
 
 func (n *Nodes) mergeNodes(keepID, mergeID int) {
@@ -223,6 +237,25 @@ func (n *Nodes) GetByMAC(mac net.HardwareAddr) *Node {
 	return nil
 }
 
+func (n *Nodes) logNode(node *Node) {
+	name := node.Name
+	if name == "" {
+		name = "??"
+	}
+	log.Printf("[node] %s", name)
+
+	var macKeys []string
+	for macKey := range node.Interfaces {
+		macKeys = append(macKeys, macKey)
+	}
+	sort.Strings(macKeys)
+
+	for _, macKey := range macKeys {
+		iface := node.Interfaces[macKey]
+		log.Printf("[node]   %s", iface)
+	}
+}
+
 func (n *Nodes) All() []*Node {
 	n.mu.RLock()
 	defer n.mu.RUnlock()

tendrils.go

@@ -17,6 +17,7 @@ type Tendrils struct {
 	DisableLLDP bool
 	DisableSNMP bool
 	LogEvents   bool
+	LogNodes    bool
 	DebugARP    bool
 	DebugLLDP   bool
 	DebugSNMP   bool