FIX: Ensure closing log files on reload

CHANGELOG.md

@@ -33,6 +33,7 @@
   `intelmq.bots.collectors.stomp.collector` and `intelmq.bots.outputs.stomp.output`
   (PR#2408 and PR#2414 by Jan Kaliszewski).
 - `intelmq.lib.upgrades`: Replace deprecated instances of `url2fqdn` experts by the new `url` expert in runtime configuration (PR#2432 by Sebastian Wagner).
+- `intelmq.lib.bot`: Ensure closing log files on reloading (PR#2435 by Kamil Mankowski).
 
 ### Development
 - Makefile: Add codespell and test commands (PR#2425 by Sebastian Wagner).

intelmq/lib/bot.py

@@ -308,10 +308,25 @@ def __handle_sighup(self):
             self.shutdown()  # disconnects, stops threads etc
         except Exception:
             self.logger.exception('Error during shutdown of bot.')
-        self.logger.handlers = []  # remove all existing handlers
+        self.__cleanup_logging_handlers()
         self.__sighup.clear()
         self.__init__(self.__bot_id_full, sighup_event=self.__sighup, standalone=self._standalone)
 
+    def __cleanup_logging_handlers(self):
+        # thread-safe removing of handlers and closing opened files
+        handlers_list = self.logger.handlers[:]
+        for handler in handlers_list:
+            try:
+                self.logger.removeHandler(handler)
+                # ensure all log files are closed to prevent caching them in RAM
+                if isinstance(handler, logging.FileHandler):
+                    handler.close()
+            except:
+                # Logger should still be safe to use even without handlers
+                # In addition, we do not want any side issue to break execution
+                #  - we are about to reinitialize logging.
+                self.logger.exception("Error while cleaning up logging handlers")
+
     def init(self):
         pass