Revamped logging

config/logging_config.py

@@ -0,0 +1,62 @@
+"""Loguru-based structured logging configuration.
+
+All logs are written to server.log as JSON lines for full traceability.
+Stdlib logging is intercepted and funneled to loguru.
+"""
+
+import logging
+from loguru import logger
+
+
+_configured = False
+
+
+class InterceptHandler(logging.Handler):
+    """Redirect stdlib logging to loguru."""
+
+    def emit(self, record: logging.LogRecord) -> None:
+        try:
+            level = logger.level(record.levelname).name
+        except ValueError:
+            level = record.levelno
+
+        frame, depth = logging.currentframe(), 2
+        while frame is not None and frame.f_code.co_filename == logging.__file__:
+            frame = frame.f_back
+            depth += 1
+
+        logger.opt(depth=depth, exception=record.exc_info).log(
+            level, record.getMessage()
+        )
+
+
+def configure_logging(log_file: str, *, force: bool = False) -> None:
+    """Configure loguru with JSON output to log_file and intercept stdlib logging.
+
+    Idempotent: skips if already configured (e.g. hot reload).
+    Use force=True to reconfigure (e.g. in tests with a different log path).
+    """
+    global _configured
+    if _configured and not force:
+        return
+    _configured = True
+
+    # Remove default loguru handler (writes to stderr)
+    logger.remove()
+
+    # Truncate log file on fresh start for clean debugging
+    open(log_file, "w", encoding="utf-8").close()
+
+    # Add file sink: JSON lines, DEBUG level, full traceability
+    logger.add(
+        log_file,
+        level="DEBUG",
+        serialize=True,
+        encoding="utf-8",
+        mode="a",
+    )
+
+    # Intercept stdlib logging: route all root logger output to loguru
+    intercept = InterceptHandler()
+    logging.root.handlers = [intercept]
+    logging.root.setLevel(logging.DEBUG)