Improve stopping server and interface mechanism

vivarium/utils/handle_server_interface.py

@@ -20,16 +20,18 @@ def get_process_pid(process_name: str):
     out, err = process.communicate()
     for line in out.splitlines():
         if process_name.encode('utf-8') in line:
-            pid = line.split()[1]
-            lg.info(f"{process_name} PID: {pid.decode()}")
-            return pid.decode()
+            pid_str = line.split()[1]
+            pid = pid_str.decode()
+            lg.warning(f" Found the process {process_name} running with this PID: {pid}")
+            return pid
 
 def kill_process(pid):
     """Kill a process by its ID
 
     :param pid: process ID
     """
     os.kill(int(pid), signal.SIGTERM)
+    lg.warning(f"Killed process with PID: {pid}")
 
 # Define parameters of the simulator
 def start_server_and_interface(scene_name: str, notebook_mode: bool = True, wait_time: int = 6):
@@ -39,7 +41,12 @@ def start_server_and_interface(scene_name: str, notebook_mode: bool = True, wait
     :param notebook_mode: notebook_mode to adapt the interface, defaults to True
     """
     # first ensure no interface or server is running
-    stop_server_and_interface()
+    processes_running = stop_server_and_interface(auto_kill=False)
+    if processes_running:
+        lg.warning("\nServer and Interface processes are still running, please stop them before starting new ones")
+        lg.warning("ERROR: New processes will not be started")
+        return
+
     # find the path to the server and interface scripts
     print(f"{os.path.dirname(__file__)}")
     project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), "../../"))
@@ -55,7 +62,7 @@ def start_server_and_interface(scene_name: str, notebook_mode: bool = True, wait
     def start_server_process():
         subprocess.run(server_command)
 
-    print("STARTING SERVER")
+    print("\nSTARTING SERVER")
     server_process = multiprocessing.Process(target=start_server_process)
     server_process.start()
     time.sleep(wait_time)
@@ -76,19 +83,50 @@ def start_interface_process():
     interface_process = multiprocessing.Process(target=start_interface_process)
     interface_process.start()
 
-def stop_server_and_interface():
+def terminate_process(pid):
+    """Terminate the process if the PID is not None"""
+    if pid is not None:
+        kill_process(pid)
+
+def stop_server_and_interface(auto_kill=False):
     """Stop the server and interface
     """
-    stopped = False
-    # interface_process_name = "vivarium/scripts/run_interface.py"
+    processes_running = False
+    interface_pid = get_process_pid(INTERFACE_PROCESS_NAME)
+    server_pid = get_process_pid(SERVER_PROCESS_NAME)
+
+    if interface_pid is not None or server_pid is not None:
+        processes_running = True
+        if auto_kill:
+            terminate_process(interface_pid)
+            terminate_process(server_pid)
+            processes_running = False
+        else:
+            message = "\nThe following processes are running:\n"
+            if interface_pid is not None:
+                message += f" - Interface (PID: {interface_pid})\n"
+            if server_pid is not None:
+                message += f" - Server (PID: {server_pid})\n"
+            message += "Do you want to stop them? (y/n): "
+            user_input = input(message)
+
+            if user_input.lower() == "y":
+                terminate_process(interface_pid)
+                terminate_process(server_pid)
+                processes_running = False
+
+    return processes_running
+
+# TODO : older version of the function, see if we remove it
+def stop_server_and_interface_unsafe():
+    """Stop the server and interface processes if they are running"""
     interface_pid = get_process_pid(INTERFACE_PROCESS_NAME)
     if interface_pid is not None:
         kill_process(interface_pid)
         stopped = True
     else: 
         lg.info("Interface process not found")
 
-    # server_process_name = "vivarium/scripts/run_server.py"
     server_pid = get_process_pid(SERVER_PROCESS_NAME)
     if server_pid is not None:
         kill_process(server_pid)
@@ -97,4 +135,4 @@ def stop_server_and_interface():
         lg.info("Server process not found")
 
     if stopped:
-        print("Server and Interface Stopped")
+        print("\nServer and Interface Stopped")