feat: Return launch and connection info from standalone launcher dry-…

…run (#3576)

* feat: Return launch and connection info from standalone launcher dry-run

* feat: use fluent_path verbatim

* feat: Add tests

* feat: Return launch and connection info from standalone launcher dry-run

* feat: doc

* fix: tests

* fix: test

* fix: test

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

@@ -168,8 +168,9 @@ def launch_fluent(
         See also :mod:`~ansys.fluent.core.launcher.fluent_container`.
     dry_run : bool, optional
         Defaults to False. If True, will not launch Fluent, and will instead print configuration information
-        that would be used as if Fluent was being launched. If dry running a container start,
-        ``launch_fluent()`` will return the configured ``container_dict``.
+        that would be used as if Fluent was being launched. If dry running a standalone start
+        ``launch_fluent()`` will return a tuple containing Fluent launch string and the server info file name.
+        If dry running a container start, ``launch_fluent()`` will return the configured ``container_dict``.
     cleanup_on_exit : bool, optional
         Whether to shut down the connected Fluent session when PyFluent is
         exited, or the ``exit()`` method is called on the session instance,

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

@@ -137,7 +137,14 @@ def get_exe_path(fluent_root: Path) -> Path:
             return fluent_root / "bin" / "fluent"
 
     # Look for Fluent exe path in the following order:
-    # 1. product_version parameter passed with launch_fluent
+    # 1. Custom Path provided by the user in launch_fluent
+    fluent_path = launch_argvals.get("fluent_path")
+    if fluent_path:
+        # Return the fluent_path string verbatim. The path may not even exist
+        # in the current machine if user wants to launch fluent externally (dry_run use case).
+        return fluent_path
+
+    # 2. product_version parameter passed with launch_fluent
     product_version = launch_argvals.get("product_version")
     if product_version:
         return get_exe_path(get_fluent_root(FluentVersion(product_version)))
@@ -147,10 +154,5 @@ def get_exe_path(fluent_root: Path) -> Path:
     if fluent_root:
         return get_exe_path(Path(fluent_root))
 
-    # 2. Custom Path provided by the user in launch_fluent
-    fluent_path = launch_argvals.get("fluent_path")
-    if fluent_path:
-        return Path(fluent_path)
-
     # 3. the latest ANSYS version from AWP_ROOT environment variables
     return get_exe_path(get_fluent_root(FluentVersion.get_latest_installed()))

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

@@ -276,9 +276,7 @@ def _get_running_session_mode(
     return session_mode.get_fluent_value()
 
 
-def _get_standalone_launch_fluent_version(
-    product_version: FluentVersion | str | float | int | None,
-) -> FluentVersion | None:
+def _get_standalone_launch_fluent_version(argvals) -> FluentVersion | None:
     """Determine the Fluent version during the execution of the ``launch_fluent()``
     method in standalone mode.
 
@@ -295,9 +293,14 @@ def _get_standalone_launch_fluent_version(
 
     # Look for Fluent version in the following order:
     # 1. product_version parameter passed with launch_fluent
+    product_version = argvals.get("product_version")
     if product_version:
         return FluentVersion(product_version)
 
+    # If fluent_path is provided, we cannot determine the Fluent version, so returning None.
+    if argvals.get("fluent_path"):
+        return None
+
     # (DEV) if "PYFLUENT_FLUENT_ROOT" environment variable is defined, we cannot
     # determine the Fluent version, so returning None.
     if os.getenv("PYFLUENT_FLUENT_ROOT"):

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

@@ -10,7 +10,27 @@
 from ansys.fluent.core.session import _parse_server_info_file
 
 
-def _get_server_info_file_name(use_tmpdir=True):
+def _get_server_info_file_names(use_tmpdir=True) -> tuple[str, str]:
+    """Returns a tuple containing server and client-side file names with the server connection information.
+    When server and client are in a different machine, the environment variable SERVER_INFO_DIR
+    can be set to a shared directory between the two machines and the server-info file will be
+    created in that directory. The value of the environment variable SERVER_INFO_DIR can be
+    different for the server and client machines. The relative path of the server-side server-info
+    file is passed to Fluent launcher and PyFluent connects to the server using the absolute path
+    of the client-side server-info file. A typical use case of the environment variable
+    SERVER_INFO_DIR is as follows:
+    - Server machine environment variable: SERVER_INFO_DIR=/mnt/shared
+    - Client machine environment variable: SERVER_INFO_DIR=\\\\server\\shared
+    - Server-side server-info file: /mnt/shared/serverinfo-xyz.txt
+    - Client-side server-info file: \\\\server\\shared\\serverinfo-xyz.txt
+    - Fluent launcher command: fluent ... -sifile=serverinfo-xyz.txt ...
+    - From PyFluent: connect_to_fluent(server_info_file_name="\\\\server\\shared\\serverinfo-xyz.txt")
+
+    When the environment variable SERVER_INFO_DIR is not set, the server-side and client-side
+    file paths for the server-info file are identical. The server-info file is created in the
+    temporary directory if ``use_tmpdir`` is True, otherwise it is created in the current working
+    directory.
+    """
     server_info_dir = os.getenv("SERVER_INFO_DIR")
     dir_ = (
         Path(server_info_dir)
@@ -19,7 +39,10 @@ def _get_server_info_file_name(use_tmpdir=True):
     )
     fd, file_name = tempfile.mkstemp(suffix=".txt", prefix="serverinfo-", dir=str(dir_))
     os.close(fd)
-    return file_name
+    if server_info_dir:
+        return Path(file_name).name, file_name
+    else:
+        return file_name, file_name
 
 
 def _get_server_info(

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

@@ -64,7 +64,7 @@
     UIMode,
     _get_argvals_and_session,
 )
-from ansys.fluent.core.launcher.server_info import _get_server_info_file_name
+from ansys.fluent.core.launcher.server_info import _get_server_info_file_names
 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
@@ -416,11 +416,14 @@ def __init__(
                     )
 
     def _prepare(self):
-        self._server_info_file_name = _get_server_info_file_name(use_tmpdir=False)
+        server_info_file_name_for_server, server_info_file_name_for_client = (
+            _get_server_info_file_names(use_tmpdir=False)
+        )
+        self._server_info_file_name = server_info_file_name_for_client
         self._argvals.update(self._argvals["scheduler_options"])
         launch_cmd = _generate_launch_string(
             self._argvals,
-            self._server_info_file_name,
+            server_info_file_name_for_server,
         )
 
         self._sifile_last_mtime = Path(self._server_info_file_name).stat().st_mtime

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

@@ -43,7 +43,7 @@
 )
 from ansys.fluent.core.launcher.server_info import (
     _get_server_info,
-    _get_server_info_file_name,
+    _get_server_info_file_names,
 )
 import ansys.fluent.core.launcher.watchdog as watchdog
 from ansys.fluent.core.utils.fluent_version import FluentVersion
@@ -128,8 +128,9 @@ def __init__(
             exited, or the ``exit()`` method is called on the session instance,
             or if the session instance becomes unreferenced. The default is ``True``.
         dry_run : bool, optional
-            Defaults to False. If True, will not launch Fluent, and will instead print configuration information
-            that would be used as if Fluent was being launched.
+            Defaults to False. If True, will not launch Fluent, and will print configuration information
+            that would be used as if Fluent was being launched. If True, the ``call()`` method will return
+            a tuple containing Fluent launch string and the server info file name.
         start_transcript : bool, optional
             Whether to start streaming the Fluent transcript in the client. The
             default is ``True``. You can stop and start the streaming of the
@@ -188,9 +189,7 @@ def __init__(
             self.argvals["start_timeout"] = 60
         if self.argvals["lightweight_mode"] is None:
             self.argvals["lightweight_mode"] = False
-        fluent_version = _get_standalone_launch_fluent_version(
-            self.argvals["product_version"]
-        )
+        fluent_version = _get_standalone_launch_fluent_version(self.argvals)
         if fluent_version:
             _raise_non_gui_exception_in_windows(self.argvals["ui_mode"], fluent_version)
 
@@ -200,10 +199,13 @@ def __init__(
         if os.getenv("PYFLUENT_FLUENT_DEBUG") == "1":
             self.argvals["fluent_debug"] = True
 
-        self._server_info_file_name = _get_server_info_file_name()
+        server_info_file_name_for_server, server_info_file_name_for_client = (
+            _get_server_info_file_names()
+        )
+        self._server_info_file_name = server_info_file_name_for_client
         self._launch_string = _generate_launch_string(
             self.argvals,
-            self._server_info_file_name,
+            server_info_file_name_for_server,
         )
 
         self._sifile_last_mtime = Path(self._server_info_file_name).stat().st_mtime
@@ -232,7 +234,7 @@ def __init__(
     def __call__(self):
         if self.argvals["dry_run"]:
             print(f"Fluent launch string: {self._launch_string}")
-            return
+            return self._launch_string, self._server_info_file_name
         try:
             logger.debug(f"Launching Fluent with command: {self._launch_cmd}")
 

tests/test_launcher.py

@@ -1,6 +1,7 @@
 import os
 from pathlib import Path
 import platform
+import tempfile
 from tempfile import TemporaryDirectory
 
 import pytest
@@ -498,3 +499,31 @@ def test_fluent_automatic_transcript(monkeypatch):
     with TemporaryDirectory(dir=pyfluent.EXAMPLES_PATH) as tmp_dir:
         with pyfluent.launch_fluent(container_dict=dict(working_dir=tmp_dir)):
             assert not list(Path(tmp_dir).glob("*.trn"))
+
+
+def test_standalone_launcher_dry_run(monkeypatch):
+    monkeypatch.setenv("PYFLUENT_LAUNCH_CONTAINER", "0")
+    fluent_path = r"\x\y\z\fluent.exe"
+    fluent_launch_string, server_info_file_name = pyfluent.launch_fluent(
+        fluent_path=fluent_path, dry_run=True, ui_mode="no_gui"
+    )
+    assert str(Path(server_info_file_name).parent) == tempfile.gettempdir()
+    assert (
+        fluent_launch_string
+        == f"{fluent_path} 3ddp -gu -sifile={server_info_file_name} -nm"
+    )
+
+
+def test_standalone_launcher_dry_run_with_server_info_dir(monkeypatch):
+    monkeypatch.setenv("PYFLUENT_LAUNCH_CONTAINER", "0")
+    with tempfile.TemporaryDirectory() as tmp_dir:
+        monkeypatch.setenv("SERVER_INFO_DIR", tmp_dir)
+        fluent_path = r"\x\y\z\fluent.exe"
+        fluent_launch_string, server_info_file_name = pyfluent.launch_fluent(
+            fluent_path=fluent_path, dry_run=True, ui_mode="no_gui"
+        )
+        assert str(Path(server_info_file_name).parent) == tmp_dir
+        assert (
+            fluent_launch_string
+            == f"{fluent_path} 3ddp -gu -sifile={Path(server_info_file_name).name} -nm"
+        )