fix: sync MTProto startup and egress fixes

internal/mtprotoedge/connection_intake.go

@@ -0,0 +1,95 @@
+package mtprotoedge
+
+import (
+	"net"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+type connectionIntakeEvent struct {
+	stage     string
+	outcome   string
+	transport string
+	remote    string
+	local     string
+	duration  time.Duration
+	bytes     int
+	err       error
+}
+
+func (s *Server) signalServing(addr net.Addr) {
+	if s.onServing != nil {
+		s.onServing(addr)
+	}
+}
+
+func (s *Server) observeConnectionIntake(event connectionIntakeEvent) {
+	fields := []zap.Field{
+		zap.String("phase", event.stage),
+		zap.String("outcome", event.outcome),
+	}
+	if event.transport != "" {
+		fields = append(fields, zap.String("transport", event.transport))
+	}
+	if event.remote != "" {
+		fields = append(fields, zap.String("remote_addr", event.remote))
+	}
+	if event.local != "" {
+		fields = append(fields, zap.String("local_addr", event.local))
+	}
+	if event.duration > 0 {
+		fields = append(fields, zap.Duration("duration", event.duration))
+	}
+	if event.bytes > 0 {
+		fields = append(fields, zap.Int("bytes", event.bytes))
+	}
+	if event.err != nil {
+		fields = append(fields, zap.Error(event.err))
+	}
+	s.log.Debug("Connection intake", fields...)
+	if metrics, ok := s.metrics.(ConnectionIntakeMetrics); ok {
+		metrics.ConnectionIntake(event.stage, event.outcome, event.duration)
+	}
+}
+
+func (s *Server) observeRawAccepts(ln net.Listener) net.Listener {
+	return &connectionObservedListener{Listener: ln, observe: s.observeConnectionIntake}
+}
+
+type connectionObservedListener struct {
+	net.Listener
+	observe func(connectionIntakeEvent)
+}
+
+func (l *connectionObservedListener) Accept() (net.Conn, error) {
+	conn, err := l.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+	l.observe(connectionIntakeEvent{
+		stage: "raw_accept", outcome: "accepted", remote: connRemote(conn), local: connLocal(conn),
+	})
+	return conn, nil
+}
+
+func connRemote(conn net.Conn) string {
+	if conn == nil || conn.RemoteAddr() == nil {
+		return ""
+	}
+	return conn.RemoteAddr().String()
+}
+
+func connLocal(conn net.Conn) string {
+	if conn == nil || conn.LocalAddr() == nil {
+		return ""
+	}
+	return conn.LocalAddr().String()
+}
+
+func intakeTransport(obfuscated bool) string {
+	if obfuscated {
+		return "obfuscated_tcp"
+	}
+	return "tcp"
+}