Call webhook on player disconnect (#396)

server/connector.go

@@ -409,6 +409,9 @@ func (c *Connector) findAndConnectBackend(ctx context.Context, frontendConn net.
 	}
 
 	defer func() {
+		if c.connectionNotifier != nil {
+			c.connectionNotifier.NotifyDisconnected(ctx, clientAddr, serverAddress, userInfo, backendHostPort)
+		}
 		c.metrics.ActiveConnections.Set(float64(
 			atomic.AddInt32(&c.activeConnections, -1)))
 		if c.recordLogins && userInfo != nil {

server/notifier.go

@@ -16,4 +16,8 @@ type ConnectionNotifier interface {
 	// NotifyConnected is called when the backend connection succeeded.
 	NotifyConnected(ctx context.Context,
 		clientAddr net.Addr, serverAddress string, playerInfo *PlayerInfo, backendHostPort string) error
+
+	// NotifyDisconnected is called when the backend connection terminates.
+	NotifyDisconnected(ctx context.Context,
+		clientAddr net.Addr, serverAddress string, playerInfo *PlayerInfo, backendHostPort string) error
 }

server/webhook_notifier.go

@@ -22,7 +22,8 @@ type WebhookNotifier struct {
 }
 
 const (
-	WebhookEventConnecting = "connect"
+	WebhookEventConnecting    = "connect"
+	WebhookEventDisconnecting = "disconnect"
 )
 
 const (
@@ -109,6 +110,24 @@ func (w *WebhookNotifier) NotifyConnected(ctx context.Context, clientAddr net.Ad
 	return w.send(ctx, payload)
 }
 
+func (w *WebhookNotifier) NotifyDisconnected(ctx context.Context, clientAddr net.Addr, serverAddress string, playerInfo *PlayerInfo, backendHostPort string) error {
+	if w.requireUser && playerInfo == nil {
+		return nil
+	}
+
+	payload := &WebhookNotifierPayload{
+		Event:           WebhookEventDisconnecting,
+		Timestamp:       time.Now(),
+		Status:          WebhookStatusSuccess,
+		Client:          ClientInfoFromAddr(clientAddr),
+		Server:          serverAddress,
+		PlayerInfo:      playerInfo,
+		BackendHostPort: backendHostPort,
+	}
+
+	return w.send(ctx, payload)
+}
+
 func (w *WebhookNotifier) send(ctx context.Context, payload *WebhookNotifierPayload) error {
 	jsonPayload, err := json.Marshal(payload)
 	if err != nil {