Improving port being busy detection (#2603)

* Improving port being busy

* Adding typing hints and docstrings

* fixing port error

* skipping tests in nostudent

* adding test.
Avoiding tests issues

* fixing tests

* fixing test

* fixing test

* skipping test on remote (since it does not make sense?)

src/ansys/mapdl/core/errors.py

@@ -111,6 +111,22 @@ def __init__(self, msg=""):
         RuntimeError.__init__(self, msg)
 
 
+class PortAlreadyInUse(MapdlDidNotStart):
+    """Error when the port is already occupied"""
+
+    def __init__(self, msg="The port {port} is already being used.", port=50052):
+        MapdlDidNotStart.__init__(self, msg.format(port=port))
+
+
+class PortAlreadyInUseByAnMAPDLInstance(PortAlreadyInUse):
+    """Error when the port is already occupied"""
+
+    def __init__(
+        self, msg="The port {port} is already used by an MAPDL instance.", port=50052
+    ):
+        PortAlreadyInUse.__init__(self, msg.format(port=port))
+
+
 class MapdlConnectionError(RuntimeError):
     """Provides the error when connecting to the MAPDL instance fails."""
 

src/ansys/mapdl/core/launcher.py

@@ -32,9 +32,11 @@
 import tempfile
 import threading
 import time
-from typing import TYPE_CHECKING, Tuple, Union
+from typing import TYPE_CHECKING, Dict, List, Optional, Tuple, Union
 import warnings
 
+import psutil
+
 try:
     import ansys.platform.instancemanagement as pypim
 
@@ -57,6 +59,8 @@
     LockFileException,
     MapdlDidNotStart,
     MapdlRuntimeError,
+    PortAlreadyInUse,
+    PortAlreadyInUseByAnMAPDLInstance,
     VersionError,
 )
 from ansys.mapdl.core.licensing import ALLOWABLE_LICENSES, LicenseChecker
@@ -113,7 +117,7 @@
 GALLERY_INSTANCE = [None]
 
 
-def _cleanup_gallery_instance():  # pragma: no cover
+def _cleanup_gallery_instance() -> None:  # pragma: no cover
     """This cleans up any left over instances of MAPDL from building the gallery."""
     if GALLERY_INSTANCE[0] is not None:
         mapdl = MapdlGrpc(
@@ -126,7 +130,7 @@ def _cleanup_gallery_instance():  # pragma: no cover
 atexit.register(_cleanup_gallery_instance)
 
 
-def _is_ubuntu():
+def _is_ubuntu() -> bool:
     """Determine if running as Ubuntu.
 
     It's a bit complicated because sometimes the distribution is
@@ -157,7 +161,7 @@ def _is_ubuntu():
         return "ubuntu" in platform.platform().lower()
 
 
-def close_all_local_instances(port_range=None):
+def close_all_local_instances(port_range: range = None) -> None:
     """Close all MAPDL instances within a port_range.
 
     This function can be used when cleaning up from a failed pool or
@@ -181,7 +185,8 @@ def close_all_local_instances(port_range=None):
         port_range = range(50000, 50200)
 
     @threaded
-    def close_mapdl(port, name="Closing mapdl thread."):
+    def close_mapdl(port: Union[int, str], name: str = "Closing mapdl thread."):
+        # Name argument is used by the threaded decorator.
         try:
             mapdl = MapdlGrpc(port=port, set_no_abort=False)
             mapdl.exit()
@@ -194,21 +199,34 @@ def close_mapdl(port, name="Closing mapdl thread."):
             close_mapdl(port)
 
 
-def check_ports(port_range, ip="localhost"):
+def check_ports(port_range: range, ip: str = "localhost") -> List[int]:
     """Check the state of ports in a port range"""
     ports = {}
     for port in port_range:
         ports[port] = port_in_use(port, ip)
     return ports
 
 
-def port_in_use(port, host=LOCALHOST):
+def port_in_use(port: Union[int, str], host: str = LOCALHOST) -> bool:
     """Returns True when a port is in use at the given host.
 
     Must actually "bind" the address.  Just checking if we can create
     a socket is insufficient as it's possible to run into permission
     errors like:
 
+    - An attempt was made to access a socket in a way forbidden by its
+      access permissions.
+    """
+    return port_in_use_using_socket(port, host) or port_in_use_using_psutil(port)
+
+
+def port_in_use_using_socket(port: Union[int, str], host: str) -> bool:
+    """Returns True when a port is in use at the given host using socket librry.
+
+    Must actually "bind" the address.  Just checking if we can create
+    a socket is insufficient as it's possible to run into permission
+    errors like:
+
     - An attempt was made to access a socket in a way forbidden by its
       access permissions.
     """
@@ -220,21 +238,49 @@ def port_in_use(port, host=LOCALHOST):
             return True
 
 
+def is_ansys_process(proc: psutil.Process) -> bool:
+    """Check if the given process is an Ansys MAPDL process"""
+    return (
+        proc.name().lower().startswith(("ansys", "mapdl")) and "-grpc" in proc.cmdline()
+    )
+
+
+def get_process_at_port(port) -> Optional[psutil.Process]:
+    """Get the process (psutil.Process) running at the given port"""
+    for proc in psutil.process_iter():
+        for conns in proc.connections(kind="inet"):
+            if conns.laddr.port == port:
+                return proc
+    return None
+
+
+def port_in_use_using_psutil(port: Union[int, str]) -> bool:
+    """Returns True when a port is in use at the given host using psutil.
+
+    This function iterate over all the process, and their connections until
+    it finds one using the given port.
+    """
+    if get_process_at_port(port):
+        return True
+    else:
+        return False
+
+
 def launch_grpc(
-    exec_file="",
-    jobname="file",
-    nproc=2,
-    ram=None,
-    run_location=None,
-    port=MAPDL_DEFAULT_PORT,
-    ip=LOCALHOST,
-    additional_switches="",
-    override=True,
-    timeout=20,
-    verbose=None,
-    add_env_vars=None,
-    replace_env_vars=None,
-    **kwargs,
+    exec_file: str = "",
+    jobname: str = "file",
+    nproc: int = 2,
+    ram: Optional[int] = None,
+    run_location: str = None,
+    port: int = MAPDL_DEFAULT_PORT,
+    ip: str = LOCALHOST,
+    additional_switches: str = "",
+    override: bool = True,
+    timeout: int = 20,
+    verbose: Optional[bool] = None,
+    add_env_vars: Optional[Dict[str, str]] = None,
+    replace_env_vars: Optional[Dict[str, str]] = None,
+    **kwargs,  # to keep compatibility with corba and console interface.
 ) -> Tuple[int, str, subprocess.Popen]:
     """Start MAPDL locally in gRPC mode.
 
@@ -457,9 +503,18 @@ def launch_grpc(
             port = max(pymapdl._LOCAL_PORTS) + 1
             LOG.debug(f"Using next available port: {port}")
 
-    while port_in_use(port) or port in pymapdl._LOCAL_PORTS:
-        port += 1
-        LOG.debug(f"Port in use.  Incrementing port number. port={port}")
+        while port_in_use(port) or port in pymapdl._LOCAL_PORTS:
+            port += 1
+            LOG.debug(f"Port in use.  Incrementing port number. port={port}")
+
+    else:
+        if port_in_use(port):
+            proc = get_process_at_port(port)
+            if is_ansys_process(proc):
+                raise PortAlreadyInUseByAnMAPDLInstance
+            else:
+                raise PortAlreadyInUse
+
     pymapdl._LOCAL_PORTS.append(port)
 
     cpu_sw = "-np %d" % nproc

src/ansys/mapdl/core/mapdl_grpc.py

@@ -424,7 +424,7 @@ def __init__(
         except MapdlConnectionError as err:  # pragma: no cover
             self._post_mortem_checks()
             self._log.debug(
-                "The error wasn't catch by the post-mortem checks.\nThe stdout is printed now:"
+                "The error wasn't caught by the post-mortem checks.\nThe stdout is printed now:"
             )
             self._log.debug(self._stdout)
 

tests/test_launcher.py

@@ -29,7 +29,11 @@
 import pytest
 
 from ansys.mapdl import core as pymapdl
-from ansys.mapdl.core.errors import LicenseServerConnectionError, MapdlDidNotStart
+from ansys.mapdl.core.errors import (
+    LicenseServerConnectionError,
+    MapdlDidNotStart,
+    PortAlreadyInUseByAnMAPDLInstance,
+)
 from ansys.mapdl.core.launcher import (
     _check_license_argument,
     _force_smp_student_version,
@@ -130,19 +134,23 @@ def test_find_ansys_linux():
 
 @requires("ansys-tools-path")
 @requires("local")
-def test_invalid_mode():
+def test_invalid_mode(mapdl):
     with pytest.raises(ValueError):
         exec_file = find_ansys(installed_mapdl_versions[0])[0]
-        pymapdl.launch_mapdl(exec_file, mode="notamode", start_timeout=start_timeout)
+        pymapdl.launch_mapdl(
+            exec_file, port=mapdl.port + 1, mode="notamode", start_timeout=start_timeout
+        )
 
 
 @requires("ansys-tools-path")
 @requires("local")
 @pytest.mark.skipif(not os.path.isfile(V150_EXEC), reason="Requires v150")
-def test_old_version():
+def test_old_version(mapdl):
     exec_file = find_ansys("150")[0]
     with pytest.raises(ValueError):
-        pymapdl.launch_mapdl(exec_file, mode="console", start_timeout=start_timeout)
+        pymapdl.launch_mapdl(
+            exec_file, port=mapdl.port + 1, mode="console", start_timeout=start_timeout
+        )
 
 
 @requires("ansys-tools-path")
@@ -238,19 +246,22 @@ def test_license_type_additional_switch():
 
 @requires("ansys-tools-path")
 @requires("local")
-def test_license_type_dummy():
+def test_license_type_dummy(mapdl):
     dummy_license_type = "dummy"
     with pytest.raises(LicenseServerConnectionError):
         launch_mapdl(
+            port=mapdl.port + 1,
             additional_switches=f" -p {dummy_license_type}" + QUICK_LAUNCH_SWITCHES,
             start_timeout=start_timeout,
         )
 
 
 @requires("local")
-def test_remove_temp_files():
+@requires("nostudent")
+def test_remove_temp_files(mapdl):
     """Ensure the working directory is removed when run_location is not set."""
     mapdl = launch_mapdl(
+        port=mapdl.port + 1,
         remove_temp_files=True,
         start_timeout=start_timeout,
         additional_switches=QUICK_LAUNCH_SWITCHES,
@@ -269,9 +280,11 @@ def test_remove_temp_files():
 
 
 @requires("local")
-def test_remove_temp_files_fail(tmpdir):
+@requires("nostudent")
+def test_remove_temp_files_fail(tmpdir, mapdl):
     """Ensure the working directory is not removed when the cwd is changed."""
     mapdl = launch_mapdl(
+        port=mapdl.port + 1,
         remove_temp_files=True,
         start_timeout=start_timeout,
         additional_switches=QUICK_LAUNCH_SWITCHES,
@@ -434,6 +447,7 @@ def test_find_ansys(mapdl):
 def test_version(mapdl):
     version = int(10 * mapdl.version)
     mapdl_ = launch_mapdl(
+        port=mapdl.port + 1,
         version=version,
         start_timeout=start_timeout,
         additional_switches=QUICK_LAUNCH_SWITCHES,
@@ -442,10 +456,11 @@ def test_version(mapdl):
 
 
 @requires("local")
-def test_raise_exec_path_and_version_launcher():
+def test_raise_exec_path_and_version_launcher(mapdl):
     with pytest.raises(ValueError):
         launch_mapdl(
             exec_file="asdf",
+            port=mapdl.port + 1,
             version="asdf",
             start_timeout=start_timeout,
             additional_switches=QUICK_LAUNCH_SWITCHES,
@@ -464,10 +479,12 @@ def test_get_default_ansys():
     assert get_default_ansys() is not None
 
 
-def test_launch_mapdl_non_recognaised_arguments():
+def test_launch_mapdl_non_recognaised_arguments(mapdl):
     with pytest.raises(ValueError, match="my_fake_argument"):
         launch_mapdl(
-            my_fake_argument="my_fake_value", additional_switches=QUICK_LAUNCH_SWITCHES
+            port=mapdl.port + 1,
+            my_fake_argument="my_fake_value",
+            additional_switches=QUICK_LAUNCH_SWITCHES,
         )
 
 
@@ -496,3 +513,9 @@ def test_launched(mapdl):
         assert mapdl.launched
     else:
         assert not mapdl.launched
+
+
+@requires("local")
+def test_launching_on_busy_port(mapdl):
+    with pytest.raises(PortAlreadyInUseByAnMAPDLInstance):
+        launch_mapdl(port=mapdl.port)

tests/test_mapdl.py

@@ -533,11 +533,14 @@ def test_lines(cleared, mapdl):
 
 
 @requires("local")
-def test_apdl_logging_start(tmpdir):
+def test_apdl_logging_start(tmpdir, mapdl):
     filename = str(tmpdir.mkdir("tmpdir").join("tmp.inp"))
 
     mapdl = launch_mapdl(
-        start_timeout=30, log_apdl=filename, additional_switches=QUICK_LAUNCH_SWITCHES
+        port=mapdl.port + 1,
+        start_timeout=30,
+        log_apdl=filename,
+        additional_switches=QUICK_LAUNCH_SWITCHES,
     )
 
     mapdl.prep7()