feat: cloud protocol - send preface bytes before packet

Author: SergeyCP

src/smartinspect/protocols/cloud/cloud_protocol.py

@@ -59,6 +59,8 @@ class CloudProtocol(TcpProtocol):
     _DEFAULT_TLS_CERTIFICATE_LOCATION: str = "resource"
     _DEFAULT_TLS_CERTIFICATE_FILEPATH: str = "client.pem"
 
+    _PREFACE_BYTES = bytes([0x29, 0x17, 0x73, 0x50])
+
     def __init__(self) -> None:
         super().__init__()
         self._reconnect_allowed: bool = True
@@ -512,6 +514,10 @@ def _internal_initialize_socket(self):
         else:
             return super()._internal_initialize_socket()
 
+    def _internal_write_packet(self, packet: Packet) -> None:
+        self._get_stream().write(self._PREFACE_BYTES)
+        super()._internal_write_packet(packet)
+
     def _internal_reconnect(self) -> bool:
         if self._reconnect_allowed:
             logger.debug("Trying to reconnect")

src/smartinspect/protocols/tcp_protocol.py

@@ -106,6 +106,9 @@ def _do_handshake(self) -> None:
         self._read_server_banner()
         self._send_client_banner()
 
+    def _get_stream(self):
+        return self.__stream
+
     def _read_server_banner(self) -> None:
         answer = self.__stream.readline().strip()
         if not answer: