improve error handling

src/elm/services/DatabaseService.py

@@ -1,8 +1,10 @@
 import logging
+import sys
 
 from beanie import init_beanie
 from pymongo import AsyncMongoClient
 from pymongo.asynchronous.collection import AsyncCollection
+from pymongo.errors import ServerSelectionTimeoutError, OperationFailure
 
 from elm.types import User, Transaction, Ticket, Seat, CateringTypes
 from elm.types.ConfigurationTypes import DatabaseConfiguration
@@ -30,6 +32,15 @@ class DatabaseService:
         if self._client is None:
             self._client = AsyncMongoClient(mongo_uri)
 
+            try:
+                await self._client.admin.command("ping")
+            except ServerSelectionTimeoutError:
+                print("Could not connect to mongodb")
+                sys.exit(1)
+            except OperationFailure:
+                print("Authentication with mongodb failed")
+                sys.exit(1)
+
             self._database = self._client[
                 self._db_config.database_name
             ]