Prevent side effects when importing logfire (#835)

Author: alexmojaki

logfire/_internal/cli.py

@@ -34,13 +34,7 @@
 BASE_OTEL_INTEGRATION_URL = 'https://opentelemetry-python-contrib.readthedocs.io/en/latest/instrumentation/'
 BASE_DOCS_URL = 'https://logfire.pydantic.dev/docs'
 INTEGRATIONS_DOCS_URL = f'{BASE_DOCS_URL}/integrations/'
-
-HOME_LOGFIRE.mkdir(exist_ok=True)
-
 LOGFIRE_LOG_FILE = HOME_LOGFIRE / 'log.txt'
-file_handler = logging.FileHandler(LOGFIRE_LOG_FILE)
-file_handler.setLevel(logging.DEBUG)
-logging.basicConfig(handlers=[file_handler], level=logging.DEBUG)
 
 logger = logging.getLogger(__name__)
 __all__ = 'main', 'logfire_info'
@@ -474,8 +468,16 @@ def log_trace_id(response: requests.Response, context: ContextCarrier, *args: An
 
 def main(args: list[str] | None = None) -> None:
     """Run the CLI."""
+    HOME_LOGFIRE.mkdir(exist_ok=True)
+
+    file_handler = logging.FileHandler(LOGFIRE_LOG_FILE)
+    file_handler.setLevel(logging.DEBUG)
+    logging.basicConfig(handlers=[file_handler], level=logging.DEBUG)
+
     try:
         _main(args)
     except KeyboardInterrupt:
         sys.stderr.write('User cancelled.\n')
         sys.exit(1)
+    finally:
+        file_handler.close()