Logging with loguru (#708)

* logging

* requirements

* add loguru dependency

* restore it

* add loguru

* set log level in .env file

* remove service fee print

* set log level

* more logging

* more logging

* more logging

* pyament.checking_id

* fix

lnbits/app.py

@@ -3,6 +3,9 @@ import importlib
 import sys
 import traceback
 import warnings
+
+from loguru import logger
+
 from http import HTTPStatus
 
 from fastapi import FastAPI, Request
@@ -41,6 +44,8 @@ def create_app(config_object="lnbits.settings") -> FastAPI:
     """Create application factory.
     :param config_object: The configuration object to use.
     """
+    set_logging_level()
+
     app = FastAPI()
     app.mount("/static", StaticFiles(directory="lnbits/static"), name="static")
     app.mount(
@@ -94,14 +99,14 @@ def check_funding_source(app: FastAPI) -> None:
             error_message, balance = await WALLET.status()
             if not error_message:
                 break
-            warnings.warn(
-                f"  × The backend for {WALLET.__class__.__name__} isn't working properly: '{error_message}'",
+            logger.error(
+                f"The backend for {WALLET.__class__.__name__} isn't working properly: '{error_message}'",
                 RuntimeWarning,
             )
-            print("Retrying connection to backend in 5 seconds...")
+            logger.info("Retrying connection to backend in 5 seconds...")
             await asyncio.sleep(5)
-        print(
-            f"  ✔️ {WALLET.__class__.__name__} seems to be connected and with a balance of {balance} msat."
+        logger.info(
+            f"✔️ Backend {WALLET.__class__.__name__} connected and with a balance of {balance} msat."
         )
 
 
@@ -124,9 +129,10 @@ def register_routes(app: FastAPI) -> None:
                 for s in ext_statics:
                     app.mount(s["path"], s["app"], s["name"])
 
+            logger.trace(f"adding route for extension {ext_module}")
             app.include_router(ext_route)
         except Exception as e:
-            print(str(e))
+            logger.error(str(e))
             raise ImportError(
                 f"Please make sure that the extension `{ext.code}` follows conventions."
             )
@@ -173,8 +179,8 @@ def register_async_tasks(app):
 def register_exception_handlers(app: FastAPI):
     @app.exception_handler(Exception)
     async def basic_error(request: Request, err):
-        print("handled error", traceback.format_exc())
-        print("ERROR:", err)
+        logger.error("handled error", traceback.format_exc())
+        logger.error("ERROR:", err)
         etype, _, tb = sys.exc_info()
         traceback.print_exception(etype, err, tb)
         exc = traceback.format_exc()
@@ -188,3 +194,10 @@ def register_exception_handlers(app: FastAPI):
             status_code=HTTPStatus.NO_CONTENT,
             content={"detail": err},
         )
+
+
+def set_logging_level() -> None:
+    """Set the logging level for the application."""
+    logger.remove()
+    log_level: str = "DEBUG" if lnbits.settings.DEBUG else "INFO"
+    logger.add(sys.stderr, level=log_level)