fix: Ansys Lab authentication (#4503)

Resolved Ansys Lab authentication issue.

---------

Co-authored-by: pyansys-ci-bot <92810346+pyansys-ci-bot@users.noreply.github.com>
Co-authored-by: Jérôme Blanche <90267895+jerome-blanche@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 4 people

doc/changelog.d/4503.fixed.md

@@ -0,0 +1 @@
+Ansys Lab authentication

src/ansys/fluent/core/launcher/pim_launcher.py

@@ -38,6 +38,8 @@
 import inspect
 import logging
 import os
+import tempfile
+import time
 from typing import Any, Dict
 
 from ansys.fluent.core.fluent_connection import FluentConnection, _get_max_c_int_limit
@@ -50,6 +52,7 @@
     UIMode,
     _get_argvals_and_session,
 )
+from ansys.fluent.core.session import _parse_server_info_file
 from ansys.fluent.core.session_meshing import Meshing
 from ansys.fluent.core.session_pure_meshing import PureMeshing
 from ansys.fluent.core.session_solver import Solver
@@ -193,6 +196,54 @@ def __call__(self):
         )
 
 
+def get_ip_port_password(
+    file_service,
+    filename="sifile.txt",
+    max_retries=20,
+    wait_time_between_retries=1,  # seconds
+):
+    """
+    Downloads the file with retries and parses server info.
+
+    Parameters
+    ----------
+    file_service: PimFileTransferService
+        Service object with method download_file(filename, target_dir).
+    filename: str
+        Name of the file to download.
+    max_retries: int
+        Maximum number of attempts.
+    wait_time_between_retries: float
+        Seconds to wait between retries (can be fractional, e.g., 0.5 for half a second).
+
+    Returns
+    -------
+        Tuple (ip, port, password) parsed from the downloaded file.
+
+    Raises
+    ------
+    TimeoutError
+        If unable to download the server info file after multiple retries.
+    """
+    with tempfile.TemporaryDirectory(prefix="fluent_sifile_") as tmpdir:
+        for attempt in range(1, max_retries + 1):
+            try:
+                file_service.download_file(filename, tmpdir)
+                break
+            except Exception as ex:
+                logger.warning(
+                    f"Attempt {attempt} of {max_retries} failed to download {filename}: {ex}"
+                )
+                if attempt == max_retries:
+                    raise TimeoutError(
+                        f"Failed to download file '{filename}' after {max_retries} attempts "
+                        f"with {wait_time_between_retries}s between retries."
+                    ) from ex
+                time.sleep(wait_time_between_retries)
+
+        return _parse_server_info_file(os.path.join(tmpdir, filename))
+
+
 def launch_remote_fluent(
     session_cls,
     start_transcript: bool,
@@ -232,6 +283,11 @@ def launch_remote_fluent(
     -------
     Meshing | PureMeshing | Solver | SolverIcing
         Session object.
+
+    Raises
+    ------
+    TimeoutError
+        If unable to download the server info file after multiple retries.
     """
 
     pim = pypim.connect()
@@ -245,6 +301,10 @@ def launch_remote_fluent(
 
     instance.wait_for_ready()
 
+    ip, port, password = get_ip_port_password(
+        file_service=PimFileTransferService(pim_instance=instance)
+    )
+
     channel = instance.build_grpc_channel(
         options=[
             ("grpc.max_send_message_length", _get_max_c_int_limit()),
@@ -253,6 +313,9 @@ def launch_remote_fluent(
     )
 
     fluent_connection = create_fluent_connection(
+        ip=ip,
+        port=port,
+        password=password,
         channel=channel,
         cleanup_on_exit=cleanup_on_exit,
         instance=instance,
@@ -288,11 +351,20 @@ def create_fluent_instance(
 
 
 def create_fluent_connection(
-    channel, cleanup_on_exit: bool, instance, launcher_args: Dict[str, Any] | None
+    ip: str,
+    port: int,
+    password: str,
+    channel,
+    cleanup_on_exit: bool,
+    instance,
+    launcher_args: Dict[str, Any] | None,
 ):
     """Create a Fluent connection."""
 
     return FluentConnection(
+        ip=ip,
+        port=port,
+        password=password,
         channel=channel,
         cleanup_on_exit=cleanup_on_exit,
         remote_instance=instance,