Fix stack overflow triggered by casefolding script

changelog.d/405.bugfix

@@ -0,0 +1 @@
+Fix stack overflow caused by settign up logging multiple times in casefolding script.

sydent/config/__init__.py

@@ -215,7 +215,7 @@ def parse_from_config_parser(self, cfg: ConfigParser) -> bool:
     def parse_config_file(self, config_file: str) -> None:
         """
         Parse the given config from a filepath, populating missing items and
-        sections. NOTE: this method also sets up logging.
+        sections.
 
         :param config_file: the file to be parsed
         """
@@ -236,13 +236,8 @@ def parse_config_file(self, config_file: str) -> None:
 
         cfg.read(config_file)
 
-        # Logging is configured in cfg, but these options must be parsed first
-        # so that we can log while parsing the rest
-        setup_logging(cfg)
-
         # TODO: Don't alter config file when starting Sydent so that
         #       it can be set to read-only
-
         needs_saving = self.parse_from_config_parser(cfg)
 
         if needs_saving:
@@ -271,13 +266,31 @@ def parse_config_dict(self, config_dict: Dict) -> None:
             for option, value in section_dict.items():
                 cfg.set(section, option, value)
 
-        # This is only ever called by tests so don't configure logging
-        # as tests do this themselves
-
         self.parse_from_config_parser(cfg)
 
 
-def setup_logging(cfg: ConfigParser) -> None:
+def setup_logging_from_file(config_file: str) -> None:
+    """
+    Parse the given config from a filepath, populating missing items and
+    sections. NOTE: this method also sets up logging.
+
+    :param config_file: the file to be parsed
+    """
+    cfg = ConfigParser()
+    if os.path.exists(config_file):
+        cfg.read(config_file)
+
+    path = cfg.get(
+        "general", "log.path", fallback=CONFIG_DEFAULTS.get("general").get("log.path")
+    )
+    level = cfg.get(
+        "general", "log.level", fallback=CONFIG_DEFAULTS.get("general").get("log.level")
+    )
+
+    _setup_logging(path, level)
+
+
+def _setup_logging(log_path: str, log_level: str) -> None:
     """
     Setup logging using the options selected in the config
 
@@ -286,10 +299,9 @@ def setup_logging(cfg: ConfigParser) -> None:
     log_format = "%(asctime)s - %(name)s - %(lineno)d - %(levelname)s" " - %(message)s"
     formatter = logging.Formatter(log_format)
 
-    logPath = cfg.get("general", "log.path")
-    if logPath != "":
+    if log_path != "":
         handler: logging.StreamHandler = logging.handlers.TimedRotatingFileHandler(
-            logPath, when="midnight", backupCount=365
+            log_path, when="midnight", backupCount=365
         )
         handler.setFormatter(formatter)
 
@@ -303,7 +315,7 @@ def sighup(signum, stack):
 
     handler.setFormatter(formatter)
     rootLogger = logging.getLogger("")
-    rootLogger.setLevel(cfg.get("general", "log.level"))
+    rootLogger.setLevel(log_level)
     rootLogger.addHandler(handler)
 
     observer = log.PythonLoggingObserver()

sydent/sydent.py

@@ -23,7 +23,7 @@
 import twisted.internet.reactor
 from twisted.internet import address, task
 
-from sydent.config import SydentConfig
+from sydent.config import SydentConfig, setup_logging_from_file
 from sydent.db.hashing_metadata import HashingMetadataStore
 from sydent.db.sqlitedb import SqliteDatabase
 from sydent.db.valsession import ThreePidValSessionStore
@@ -307,8 +307,11 @@ def run_gc():
 
 
 if __name__ == "__main__":
+    config_file = get_config_file_path()
+    setup_logging_from_file(config_file)
+
     sydent_config = SydentConfig()
-    sydent_config.parse_config_file(get_config_file_path())
+    sydent_config.parse_config_file(config_file)
 
     syd = Sydent(sydent_config)
     syd.run()