auto find next available local port

packages/node/meshnet_node/cli.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import argparse
+import socket
 import sys
 import time
 from pathlib import Path
@@ -49,6 +50,19 @@ def _run_node(cfg: dict) -> None:
         )
 
 
+def _first_available_port(host: str, start: int = 7000, attempts: int = 100) -> int:
+    """Return the first TCP port bindable on host, starting at start."""
+    bind_host = "" if host == "0.0.0.0" else host
+    for port in range(start, start + attempts):
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
+            try:
+                sock.bind((bind_host, port))
+            except OSError:
+                continue
+            return port
+    raise OSError(f"no available TCP port in range {start}-{start + attempts - 1}")
+
+
 def _cmd_default(args) -> int:
     """No subcommand: wizard if no config, else start with saved config."""
     from .config import load_config, save_config, merge_cli_overrides
@@ -145,7 +159,7 @@ def _cmd_start(args) -> int:
     # Build a transient config from flags (don't write to disk)
     cfg = dict(DEFAULTS)
     cfg["tracker_url"] = args.tracker
-    cfg["port"] = args.port
+    cfg["port"] = args.port if args.port is not None else _first_available_port(args.host)
     if args.model_id is None and "/" in args.model:
         cfg["model_hf_repo"] = args.model
         cfg["model_name"] = args.model.split("/")[-1]
@@ -236,7 +250,7 @@ def main() -> None:
     # start subcommand (legacy / backward-compat)
     start_cmd = subparsers.add_parser("start", help="Start node (legacy flags)")
     start_cmd.add_argument("--tracker", default="http://localhost:8080")
-    start_cmd.add_argument("--port", type=int, default=7000)
+    start_cmd.add_argument("--port", type=int)
     start_cmd.add_argument("--model", default="stub-model")
     start_cmd.add_argument("--model-id", help="HuggingFace repo ID")
     start_cmd.add_argument("--shard-start", type=int)