Refactor backend to use request-scoped SQLite connections

backend/app/tasks/history_sync.py

@@ -9,8 +9,12 @@ from __future__ import annotations
 import datetime
 from typing import TYPE_CHECKING
 
+if TYPE_CHECKING:
+    import aiosqlite
+
 import structlog
 
+from app.db import open_db
 from app.repositories import fail2ban_db_repo
 from app.utils.fail2ban_db_utils import get_fail2ban_db_path
 
@@ -29,6 +33,15 @@ HISTORY_SYNC_INTERVAL: int = 300
 BACKFILL_WINDOW: int = 648000
 
 
+async def _get_db(app: FastAPI) -> tuple[aiosqlite.Connection, bool]:
+    existing_db = getattr(app.state, "db", None)
+    if existing_db is not None:
+        return existing_db, False
+
+    db = await open_db(app.state.settings.database_path)
+    return db, True
+
+
 async def _get_last_archive_ts(db) -> int | None:
     async with db.execute("SELECT MAX(timeofban) FROM history_archive") as cur:
         row = await cur.fetchone()
@@ -38,8 +51,8 @@ async def _get_last_archive_ts(db) -> int | None:
 
 
 async def _run_sync(app: FastAPI) -> None:
-    db = app.state.db
     socket_path: str = app.state.settings.fail2ban_socket
+    db, close_db = await _get_db(app)
 
     try:
         last_ts = await _get_last_archive_ts(db)
@@ -90,6 +103,9 @@ async def _run_sync(app: FastAPI) -> None:
 
     except Exception:
         log.exception("history_sync_failed")
+    finally:
+        if close_db:
+            await db.close()
 
 
 def register(app: FastAPI) -> None: