feat: DB再起動、時間経過後のコネクション再確立の仕込み

ecs/jskult-webapp/src/db/database.py

@@ -1,10 +1,28 @@
 from sqlalchemy import (Connection, CursorResult, Engine, QueuePool,
-                        create_engine, text)
+                        create_engine, event, exc, text)
 from sqlalchemy.engine.url import URL
+from sqlalchemy.pool import Pool
 
 from src.error.exceptions import DBException
+from src.logging.get_logger import get_logger
 from src.system_var import environment
 
+logger = get_logger('DB接続')
+
+
+@event.listens_for(Pool, 'checkout')
+def ping_connection(dbapi_connection, connection_record, connection_proxy):
+    """コネクションが切れた場合、再接続"""
+    cursor = dbapi_connection.cursor()
+    try:
+        cursor.execute("SELECT 1")
+    except Exception as e:
+        logger.info(f'DB接続に失敗したため、リトライします: {e}')
+        # raise DisconnectionError - pool will try
+        # connecting again up to three times before raising.
+        raise exc.DisconnectionError()
+    cursor.close()
+
 
 class Database:
     """データベース操作クラス"""