add basic metrics for stress testing

proxy/internal/roundtrip/netbird.go

@@ -55,6 +55,8 @@ type managementClient interface {
 	CreateProxyPeer(ctx context.Context, req *proto.CreateProxyPeerRequest, opts ...grpc.CallOption) (*proto.CreateProxyPeerResponse, error)
 }
 
+type backendMetricRecorder func(duration time.Duration)
+
 // NetBird provides an http.RoundTripper implementation
 // backed by underlying NetBird connections.
 // Clients are keyed by AccountID, allowing multiple domains to share the same connection.
@@ -70,6 +72,8 @@ type NetBird struct {
 	clients        map[types.AccountID]*clientEntry
 	initLogOnce    sync.Once
 	statusNotifier statusNotifier
+
+	recordBackendDuration backendMetricRecorder
 }
 
 // ClientDebugInfo contains debug information about a client.
@@ -375,6 +379,10 @@ func (n *NetBird) RoundTrip(req *http.Request) (*http.Response, error) {
 	resp, err := transport.RoundTrip(req)
 	duration := time.Since(start)
 
+	if n.recordBackendDuration != nil {
+		n.recordBackendDuration(duration)
+	}
+
 	if err != nil {
 		n.logger.Debugf("roundtrip: method=%s host=%s url=%s account=%s duration=%s err=%v",
 			req.Method, req.Host, req.URL.String(), accountID, duration.Truncate(time.Millisecond), err)
@@ -483,19 +491,20 @@ func (n *NetBird) ListClientsForStartup() map[types.AccountID]*embed.Client {
 // NewNetBird creates a new NetBird transport. Set wgPort to 0 for a random
 // OS-assigned port. A fixed port only works with single-account deployments;
 // multiple accounts will fail to bind the same port.
-func NewNetBird(mgmtAddr, proxyID, proxyAddr string, wgPort int, logger *log.Logger, notifier statusNotifier, mgmtClient managementClient) *NetBird {
+func NewNetBird(mgmtAddr, proxyID, proxyAddr string, wgPort int, logger *log.Logger, notifier statusNotifier, mgmtClient managementClient, metric backendMetricRecorder) *NetBird {
 	if logger == nil {
 		logger = log.StandardLogger()
 	}
 	return &NetBird{
-		mgmtAddr:       mgmtAddr,
-		proxyID:        proxyID,
-		proxyAddr:      proxyAddr,
-		wgPort:         wgPort,
-		logger:         logger,
-		clients:        make(map[types.AccountID]*clientEntry),
-		statusNotifier: notifier,
-		mgmtClient:     mgmtClient,
+		mgmtAddr:              mgmtAddr,
+		proxyID:               proxyID,
+		proxyAddr:             proxyAddr,
+		wgPort:                wgPort,
+		logger:                logger,
+		clients:               make(map[types.AccountID]*clientEntry),
+		statusNotifier:        notifier,
+		mgmtClient:            mgmtClient,
+		recordBackendDuration: metric,
 	}
 }
 

proxy/internal/roundtrip/netbird_test.go

@@ -23,7 +23,7 @@ func (m *mockMgmtClient) CreateProxyPeer(_ context.Context, _ *proto.CreateProxy
 // mockNetBird creates a NetBird instance for testing without actually connecting.
 // It uses an invalid management URL to prevent real connections.
 func mockNetBird() *NetBird {
-	return NewNetBird("http://invalid.test:9999", "test-proxy", 0, nil, nil, &mockMgmtClient{})
+	return NewNetBird("http://invalid.test:9999", "test-proxy", "localhost", 0, nil, nil, &mockMgmtClient{}, nil)
 }
 
 func TestNetBird_AddPeer_CreatesClientForNewAccount(t *testing.T) {