add webhook event for peer state change (#444)

new event types: connect and disconnect

example payload:

```json
{
  "event": "connect",
  "entity": "peer",
  "identifier": "Fb5TaziAs1WrPBjC/MFbWsIelVXvi0hDKZ3YQM9wmU8=",
  "payload": {
    "PeerId": "Fb5TaziAs1WrPBjC/MFbWsIelVXvi0hDKZ3YQM9wmU8=",
    "IsConnected": true,
    "IsPingable": false,
    "LastPing": null,
    "BytesReceived": 1860,
    "BytesTransmitted": 10824,
    "LastHandshake": "2025-06-26T23:04:33.325216659+02:00",
    "Endpoint": "10.55.66.77:33874",
    "LastSessionStart": "2025-06-26T22:50:40.10221606+02:00"
  }
}
```

internal/adapters/metrics.go

@@ -133,5 +133,5 @@ func (m *MetricsServer) UpdatePeerMetrics(peer *domain.Peer, status domain.PeerS
 	}
 	m.peerReceivedBytesTotal.WithLabelValues(labels...).Set(float64(status.BytesReceived))
 	m.peerSendBytesTotal.WithLabelValues(labels...).Set(float64(status.BytesTransmitted))
-	m.peerIsConnected.WithLabelValues(labels...).Set(internal.BoolToFloat64(status.IsConnected()))
+	m.peerIsConnected.WithLabelValues(labels...).Set(internal.BoolToFloat64(status.IsConnected))
 }

internal/app/api/v0/model/models_peer.go

@@ -198,7 +198,7 @@ func NewPeerStats(enabled bool, src []domain.PeerStatus) *PeerStats {
 
 	for _, srcStat := range src {
 		stats[string(srcStat.PeerId)] = PeerStatData{
-			IsConnected:      srcStat.IsConnected(),
+			IsConnected:      srcStat.IsConnected,
 			IsPingable:       srcStat.IsPingable,
 			LastPing:         srcStat.LastPing,
 			BytesReceived:    srcStat.BytesReceived,

internal/app/eventbus.go

@@ -36,6 +36,7 @@ const TopicPeerDeleted = "peer:deleted"
 const TopicPeerUpdated = "peer:updated"
 const TopicPeerInterfaceUpdated = "peer:interface:updated"
 const TopicPeerIdentifierUpdated = "peer:identifier:updated"
+const TopicPeerStateChanged = "peer:state:changed"
 
 // endregion peer-events
 

internal/app/webhooks/manager.go

@@ -64,6 +64,7 @@ func (m Manager) connectToMessageBus() {
 	_ = m.bus.Subscribe(app.TopicPeerCreated, m.handlePeerCreateEvent)
 	_ = m.bus.Subscribe(app.TopicPeerUpdated, m.handlePeerUpdateEvent)
 	_ = m.bus.Subscribe(app.TopicPeerDeleted, m.handlePeerDeleteEvent)
+	_ = m.bus.Subscribe(app.TopicPeerStateChanged, m.handlePeerStateChangeEvent)
 
 	_ = m.bus.Subscribe(app.TopicInterfaceCreated, m.handleInterfaceCreateEvent)
 	_ = m.bus.Subscribe(app.TopicInterfaceUpdated, m.handleInterfaceUpdateEvent)
@@ -135,6 +136,14 @@ func (m Manager) handleInterfaceDeleteEvent(iface domain.Interface) {
 	m.handleGenericEvent(WebhookEventDelete, iface)
 }
 
+func (m Manager) handlePeerStateChangeEvent(peerStatus domain.PeerStatus) {
+	if peerStatus.IsConnected {
+		m.handleGenericEvent(WebhookEventConnect, peerStatus)
+	} else {
+		m.handleGenericEvent(WebhookEventDisconnect, peerStatus)
+	}
+}
+
 func (m Manager) handleGenericEvent(action WebhookEvent, payload any) {
 	eventData, err := m.createWebhookData(action, payload)
 	if err != nil {
@@ -177,6 +186,9 @@ func (m Manager) createWebhookData(action WebhookEvent, payload any) (*WebhookDa
 	case domain.Interface:
 		d.Entity = WebhookEntityInterface
 		d.Identifier = string(v.Identifier)
+	case domain.PeerStatus:
+		d.Entity = WebhookEntityPeer
+		d.Identifier = string(v.PeerId)
 	default:
 		return nil, fmt.Errorf("unsupported payload type: %T", v)
 	}

internal/app/webhooks/model.go

@@ -45,4 +45,6 @@ const (
 	WebhookEventCreate     WebhookEvent = "create"
 	WebhookEventUpdate     WebhookEvent = "update"
 	WebhookEventDelete     WebhookEvent = "delete"
+	WebhookEventConnect    WebhookEvent = "connect"
+	WebhookEventDisconnect WebhookEvent = "disconnect"
 )

internal/app/wireguard/statistics.go

@@ -43,6 +43,8 @@ type StatisticsMetricsServer interface {
 type StatisticsEventBus interface {
 	// Subscribe subscribes to a topic
 	Subscribe(topic string, fn interface{}) error
+	// Publish sends a message to the message bus.
+	Publish(topic string, args ...any)
 }
 
 type StatisticsCollector struct {
@@ -55,6 +57,8 @@ type StatisticsCollector struct {
 	db StatisticsDatabaseRepo
 	wg StatisticsInterfaceController
 	ms StatisticsMetricsServer
+
+	peerChangeEvent chan domain.PeerIdentifier
 }
 
 // NewStatisticsCollector creates a new statistics collector.
@@ -171,8 +175,12 @@ func (c *StatisticsCollector) collectPeerData(ctx context.Context) {
 					continue
 				}
 				for _, peer := range peers {
+					var connectionStateChanged bool
+					var newPeerStatus domain.PeerStatus
 					err = c.db.UpdatePeerStatus(ctx, peer.Identifier,
 						func(p *domain.PeerStatus) (*domain.PeerStatus, error) {
+							wasConnected := p.IsConnected
+
 							var lastHandshake *time.Time
 							if !peer.LastHandshake.IsZero() {
 								lastHandshake = &peer.LastHandshake
@@ -186,6 +194,12 @@ func (c *StatisticsCollector) collectPeerData(ctx context.Context) {
 							p.BytesTransmitted = peer.BytesDownload // store bytes that where received from the peer and sent by the server
 							p.Endpoint = peer.Endpoint
 							p.LastHandshake = lastHandshake
+							p.CalcConnected()
+
+							if wasConnected != p.IsConnected {
+								connectionStateChanged = true
+								newPeerStatus = *p // store new status for event publishing
+							}
 
 							// Update prometheus metrics
 							go c.updatePeerMetrics(ctx, *p)
@@ -197,6 +211,11 @@ func (c *StatisticsCollector) collectPeerData(ctx context.Context) {
 					} else {
 						slog.Debug("updated peer status", "peer", peer.Identifier)
 					}
+
+					if connectionStateChanged {
+						// publish event if connection state changed
+						c.bus.Publish(app.TopicPeerStateChanged, newPeerStatus)
+					}
 				}
 			}
 		}
@@ -298,12 +317,17 @@ func (c *StatisticsCollector) enqueuePingChecks(ctx context.Context) {
 func (c *StatisticsCollector) pingWorker(ctx context.Context) {
 	defer c.pingWaitGroup.Done()
 	for peer := range c.pingJobs {
+		var connectionStateChanged bool
+		var newPeerStatus domain.PeerStatus
+
 		peerPingable := c.isPeerPingable(ctx, peer)
 		slog.Debug("peer ping check completed", "peer", peer.Identifier, "pingable", peerPingable)
 
 		now := time.Now()
 		err := c.db.UpdatePeerStatus(ctx, peer.Identifier,
 			func(p *domain.PeerStatus) (*domain.PeerStatus, error) {
+				wasConnected := p.IsConnected
+
 				if peerPingable {
 					p.IsPingable = true
 					p.LastPing = &now
@@ -311,6 +335,13 @@ func (c *StatisticsCollector) pingWorker(ctx context.Context) {
 					p.IsPingable = false
 					p.LastPing = nil
 				}
+				p.UpdatedAt = time.Now()
+				p.CalcConnected()
+
+				if wasConnected != p.IsConnected {
+					connectionStateChanged = true
+					newPeerStatus = *p // store new status for event publishing
+				}
 
 				// Update prometheus metrics
 				go c.updatePeerMetrics(ctx, *p)
@@ -322,6 +353,11 @@ func (c *StatisticsCollector) pingWorker(ctx context.Context) {
 		} else {
 			slog.Debug("updated peer ping status", "peer", peer.Identifier)
 		}
+
+		if connectionStateChanged {
+			// publish event if connection state changed
+			c.bus.Publish(app.TopicPeerStateChanged, newPeerStatus)
+		}
 	}
 }
 

internal/domain/statistics.go

@@ -3,21 +3,23 @@ package domain
 import "time"
 
 type PeerStatus struct {
-	PeerId    PeerIdentifier `gorm:"primaryKey;column:identifier"`
-	UpdatedAt time.Time      `gorm:"column:updated_at"`
+	PeerId    PeerIdentifier `gorm:"primaryKey;column:identifier" json:"PeerId"`
+	UpdatedAt time.Time      `gorm:"column:updated_at" json:"-"`
 
-	IsPingable bool       `gorm:"column:pingable"`
-	LastPing   *time.Time `gorm:"column:last_ping"`
+	IsConnected bool `gorm:"column:connected" json:"IsConnected"` // indicates if the peer is connected based on the last handshake or ping
 
-	BytesReceived    uint64 `gorm:"column:received"`
-	BytesTransmitted uint64 `gorm:"column:transmitted"`
+	IsPingable bool       `gorm:"column:pingable" json:"IsPingable"`
+	LastPing   *time.Time `gorm:"column:last_ping" json:"LastPing"`
 
-	LastHandshake    *time.Time `gorm:"column:last_handshake"`
-	Endpoint         string     `gorm:"column:endpoint"`
-	LastSessionStart *time.Time `gorm:"column:last_session_start"`
+	BytesReceived    uint64 `gorm:"column:received" json:"BytesReceived"`
+	BytesTransmitted uint64 `gorm:"column:transmitted" json:"BytesTransmitted"`
+
+	LastHandshake    *time.Time `gorm:"column:last_handshake" json:"LastHandshake"`
+	Endpoint         string     `gorm:"column:endpoint" json:"Endpoint"`
+	LastSessionStart *time.Time `gorm:"column:last_session_start" json:"LastSessionStart"`
 }
 
-func (s PeerStatus) IsConnected() bool {
+func (s *PeerStatus) CalcConnected() {
 	oldestHandshakeTime := time.Now().Add(-2 * time.Minute) // if a handshake is older than 2 minutes, the peer is no longer connected
 
 	handshakeValid := false
@@ -25,7 +27,7 @@ func (s PeerStatus) IsConnected() bool {
 		handshakeValid = !s.LastHandshake.Before(oldestHandshakeTime)
 	}
 
-	return s.IsPingable || handshakeValid
+	s.IsConnected = s.IsPingable || handshakeValid
 }
 
 type InterfaceStatus struct {

internal/domain/statistics_test.go

@@ -66,8 +66,9 @@ func TestPeerStatus_IsConnected(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := tt.status.IsConnected(); got != tt.want {
-				t.Errorf("IsConnected() = %v, want %v", got, tt.want)
+			tt.status.CalcConnected()
+			if got := tt.status.IsConnected; got != tt.want {
+				t.Errorf("IsConnected = %v, want %v", got, tt.want)
 			}
 		})
 	}