rename log-reasons to log-events with structured prefixes

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

cmd/tendrils/main.go

@@ -11,7 +11,7 @@ func main() {
 	noARP := flag.Bool("no-arp", false, "disable ARP discovery")
 	noLLDP := flag.Bool("no-lldp", false, "disable LLDP discovery")
 	noSNMP := flag.Bool("no-snmp", false, "disable SNMP discovery")
-	logReasons := flag.Bool("log-reasons", false, "log addition reasons")
+	logEvents := flag.Bool("log-events", false, "log node events")
 	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")
@@ -22,7 +22,7 @@ func main() {
 	t.DisableARP = *noARP
 	t.DisableLLDP = *noLLDP
 	t.DisableSNMP = *noSNMP
-	t.LogReasons = *logReasons
+	t.LogEvents = *logEvents
 	t.DebugARP = *debugARP
 	t.DebugLLDP = *debugLLDP
 	t.DebugSNMP = *debugSNMP

nodes.go

@@ -84,6 +84,7 @@ func (n *Nodes) Update(ips []net.IP, macs []net.HardwareAddr, source string) {
 	}
 
 	var targetID int
+	isNew := false
 	if len(existingIDs) == 0 {
 		targetID = n.nextID
 		n.nextID++
@@ -91,6 +92,7 @@ func (n *Nodes) Update(ips []net.IP, macs []net.HardwareAddr, source string) {
 			IPs:  map[string]net.IP{},
 			MACs: map[string]net.HardwareAddr{},
 		}
+		isNew = true
 	} else if len(existingIDs) == 1 {
 		for id := range existingIDs {
 			targetID = id
@@ -106,8 +108,8 @@ func (n *Nodes) Update(ips []net.IP, macs []net.HardwareAddr, source string) {
 			merging = append(merging, n.nodes[ids[i]].String())
 			n.mergeNodes(targetID, ids[i])
 		}
-		if n.t.LogReasons {
-			log.Printf("merged nodes %v into %s (via %s)", merging, n.nodes[targetID], source)
+		if n.t.LogEvents {
+			log.Printf("[merge] %v into %s (via %s)", merging, n.nodes[targetID], source)
 		}
 	}
 
@@ -132,8 +134,12 @@ func (n *Nodes) Update(ips []net.IP, macs []net.HardwareAddr, source string) {
 		n.macIndex[macKey] = targetID
 	}
 
-	if len(added) > 0 && n.t.LogReasons {
-		log.Printf("updated %s +%v (via %s)", node, added, source)
+	if len(added) > 0 && 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)
+		}
 	}
 }
 

tendrils.go

@@ -16,7 +16,7 @@ type Tendrils struct {
 	DisableARP  bool
 	DisableLLDP bool
 	DisableSNMP bool
-	LogReasons  bool
+	LogEvents   bool
 	DebugARP    bool
 	DebugLLDP   bool
 	DebugSNMP   bool