restore _getuid() - this partly reverts "[OMCProcessDocker*] remove user handling - it was needed for the OMC ZMQ port file ..."

This reverts commit 969cce176ddd20fcdf304712863ccc10af431afd.

Author: syntron

OMPython/OMCSession.py

@@ -680,6 +680,15 @@ def _omc_port_get(self) -> str:
 
         return port
 
+    @staticmethod
+    def _getuid() -> int:
+        """
+        The uid to give to docker.
+        On Windows, volumes are mapped with all files are chmod ugo+rwx,
+        so uid does not matter as long as it is not the root user.
+        """
+        return 1000 if sys.platform == 'win32' else os.getuid()
+
     def get_server_address(self) -> Optional[str]:
         if self._dockerNetwork == "separate" and isinstance(self._dockerCid, str):
             output = subprocess.check_output(["docker", "inspect", self._dockerCid]).decode().strip()
@@ -781,6 +790,7 @@ def _docker_omc_cmd(
                            "docker", "run",
                            "--cidfile", docker_cid_file.as_posix(),
                            "--rm",
+                           "--user", str(self._getuid()),
                        ]
                        + self._dockerExtraArgs
                        + dockerNetworkStr
@@ -887,7 +897,10 @@ def _docker_omc_cmd(self, omc_path_and_args_list) -> list:
         if isinstance(self._interactivePort, int):
             extraFlags = extraFlags + [f"--interactivePort={int(self._interactivePort)}"]
 
-        omc_command = (["docker", "exec"]
+        omc_command = ([
+                           "docker", "exec",
+                           "--user", str(self._getuid()),
+                       ]
                        + self._dockerExtraArgs
                        + [self._dockerCid, self._dockerOpenModelicaPath]
                        + omc_path_and_args_list