actually use fastapi lifetime manager to setup logging

backend/src/logging_config.py

@@ -0,0 +1,56 @@
+"""Sets up global logging configuration for the application."""
+
+import logging
+import os
+
+logger = logging.getLogger(__name__)
+
+
+def configure_logging():
+    """
+    Called at startup of a FastAPI application instance to setup logging. Depending on the environment, it will log to stdout or to Loki.
+    """
+
+    is_debug = os.getenv('DEBUG', "false") == "true"
+    is_kubernetes = os.getenv('KUBERNETES_SERVICE_HOST') is not None
+
+
+    if not is_kubernetes:
+        # in that case we want to log to stdout and also to loki
+        from loki_logger_handler.loki_logger_handler import LokiLoggerHandler
+        loki_url = os.getenv('LOKI_URL')
+        loki_url = "http://localhost:3100/loki/api/v1/push"
+        if loki_url is None:
+            raise ValueError("LOKI_URL environment variable is not set")
+        
+        loki_handler = LokiLoggerHandler(
+            url = loki_url,
+            labels = {'app': 'anyway', 'environment': 'staging' if is_debug else 'production'}
+        )
+
+        logger.info(f"Logging to Loki at {loki_url} with {loki_handler.labels} and {is_debug=}")
+        logging_handlers = [loki_handler, logging.StreamHandler()]
+        logging_level = logging.DEBUG if is_debug else logging.INFO
+        # no need for time since it's added by loki or can be shown in kube logs
+        logging_format = '%(name)s - %(levelname)s - %(message)s'
+
+    else:
+        # if we are in a debug (local) session, set verbose and rich logging
+        from rich.logging import RichHandler
+        logging_handlers = [RichHandler()]
+        logging_level = logging.DEBUG if is_debug else logging.INFO
+        logging_format = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+
+
+
+    logging.basicConfig(
+        level = logging_level,
+        format = logging_format,
+        handlers = logging_handlers
+    )
+
+    # also overwrite the uvicorn loggers
+    logging.getLogger('uvicorn').handlers = logging_handlers
+    logging.getLogger('uvicorn.access').handlers = logging_handlers
+    logging.getLogger('uvicorn.error').handlers = logging_handlers
+