use daemon thread for get_interface_stats to timeout long-running checks, with...

use daemon thread for get_interface_stats to timeout long-running checks, with debug output when it happens

brian_polling_manager/interface_stats/cli.py

 import enum
 import json
-import logging.config
+import logging
 import sys
+import threading
+import traceback
 from datetime import datetime
 from logging import LogRecord
 from typing import Any, Collection, Dict, Iterable, List
@@ -15,9 +17,9 @@ from brian_polling_manager.inventory import (
     load_inventory_json,
 )
 
-from .common import PointGroup, RouterProcessor
-from .juniper import JuniperRouterProcessor
-from .nokia import NokiaRouterProcessor
+from brian_polling_manager.interface_stats.common import PointGroup, RouterProcessor
+from brian_polling_manager.interface_stats.juniper import JuniperRouterProcessor
+from brian_polling_manager.interface_stats.nokia import NokiaRouterProcessor
 
 logger = logging.getLogger()
 
@@ -177,7 +179,7 @@ def _log_interface_points_sorted(points: Collection[dict], point_group: PointGro
     longest_ifc = max(len(i) for i in interfaces)
     ifc_count = len(interfaces)
     for n in range(ifc_count // N_COLUMNS + (ifc_count % N_COLUMNS > 0)):
-        ifc_slice = interfaces[n * N_COLUMNS : (n + 1) * N_COLUMNS]
+        ifc_slice = interfaces[n * N_COLUMNS: (n + 1) * N_COLUMNS]
         logger.info("    ".join(i.ljust(longest_ifc) for i in ifc_slice))
 
 
@@ -224,7 +226,7 @@ def main(
 def validate_config(_unused_ctx, _unused_param, file):
     # import here because this is the only place we use the config module, and we want
     # to reuse the name `config` for other purposes elsewheres
-    from . import config
+    from brian_polling_manager.interface_stats import config
 
     try:
         return config.load(file)
@@ -295,11 +297,24 @@ def cli(
     error_counter = setup_logging(debug=verbose)
 
     try:
-        main(
-            processor=processor,
-            interfaces=interfaces if interfaces else ALL_,
-            output=OutputMethod.from_string(output.lower()),
+        thread = threading.Thread(
+            target=main,
+            args=(processor, interfaces if interfaces else ALL_, OutputMethod.from_string(output.lower())),
         )
+        thread.daemon = True
+        thread.start()
+        thread.join(timeout=120)
+        if thread.is_alive():
+            logger.error("Thread timed out")
+            frames = sys._current_frames()
+            for thread_id, frame in frames.items():
+                if thread_id == thread.ident:
+                    logger.error("Thread stack trace:")
+                    for line in traceback.format_stack(frame):
+                        logger.error(line.strip())
+                    logger.error(f"-- Thread stack trace end --")
+            raise click.exceptions.Exit(2)
+
     except Exception:
         logger.exception(
             f"Error while processing {processor.name.capitalize()} router {router_fqdn}"