Improve logging a bit

app/main.py

@@ -1,5 +1,6 @@
 import logging
 logger = logging.getLogger(__name__)
+import os
 from fastapi import FastAPI
 from fastapi.security import OAuth2PasswordBearer
 from contextlib import asynccontextmanager
@@ -14,10 +15,18 @@ oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")
 scanner = BackgroundScanner(db=get_db_session())
 logging.basicConfig(level=logging.INFO)
 
+def checkDeps():
+    load_dotenv()
+    MIFARE_APP_MASTER_KEY = os.getenv('MIFARE_APP_MASTER_KEY')
+    if not MIFARE_APP_MASTER_KEY:
+        logger.critical(f"MIFARE APP MASTER KEY not found!")
+        logger.critical("Writing and reading cards is disabled!")
+        global disableCards
+        disableCards = True
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
-    load_dotenv()
+    checkDeps()
     create_db_and_tables()
     create_first_user(db=get_db_session())
     logger.info("Database created and tables initialized.")