fix: use lazy refresh for Cloud SQL Connector (#144)

Author: jackwotherspoon

pyproject.toml

@@ -10,7 +10,7 @@ authors = [
 ]
 
 dependencies = [
-    "cloud-sql-python-connector[asyncpg] >= 1.7.0, <2.0.0",
+    "cloud-sql-python-connector[asyncpg] >= 1.10.0, <2.0.0",
     "langchain-core>=0.1.1, <1.0.0 ",
     "langchain-community>=0.0.18, <0.3.0",
     "numpy>=1.24.4, <2.0.0",

src/langchain_google_cloud_sql_pg/engine.py

@@ -22,7 +22,7 @@
 import aiohttp
 import google.auth  # type: ignore
 import google.auth.transport.requests  # type: ignore
-from google.cloud.sql.connector import Connector, IPTypes
+from google.cloud.sql.connector import Connector, IPTypes, RefreshStrategy
 from sqlalchemy import MetaData, Table, text
 from sqlalchemy.exc import InvalidRequestError
 from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
@@ -158,6 +158,7 @@ async def _create(
                 loop=asyncio.get_event_loop(),
                 user_agent=USER_AGENT,
                 quota_project=quota_project,
+                refresh_strategy=RefreshStrategy.LAZY,
             )
 
         # if user and password are given, use basic auth