Cloud SQL Python Connector

The Cloud SQL Python Connector is a Cloud SQL connector designed for use with the Python language. Using a Cloud SQL connector provides the following benefits:

• IAM Authorization: uses IAM permissions to control who/what can connect to your Cloud SQL instances
• Improved Security: uses robust, updated TLS 1.3 encryption and identity verification between the client connector and the server-side proxy, independent of the database protocol.
• Convenience: removes the requirement to use and distribute SSL certificates, as well as manage firewalls or source/destination IP addresses.
• (optionally) IAM DB Authentication: provides support for Cloud SQL’s automatic IAM DB AuthN feature.

The Cloud SQL Python Connector is a package to be used alongside a database driver. Currently supported drivers are:

• pymysql (MySQL)
• pg8000 (PostgreSQL)
• asyncpg (PostgreSQL)
• pytds (SQL Server)

Installation

You can install this library with pip install, specifying the driver based on your database dialect.

MySQL

pip install "cloud-sql-python-connector[pymysql]"

Postgres

There are two different database drivers that are supported for the Postgres dialect:

pg8000

pip install "cloud-sql-python-connector[pg8000]"

asyncpg

pip install "cloud-sql-python-connector[asyncpg]"

SQL Server

pip install "cloud-sql-python-connector[pytds]"

Usage

This package provides several functions for authorizing and encrypting connections. These functions are used with your database driver to connect to your Cloud SQL instance.

The instance connection name for your Cloud SQL instance is always in the format "project:region:instance".

APIs and Services

This package requires the following to successfully make Cloud SQL Connections:

• IAM principal (user, service account, etc.) with the Cloud SQL Client role. This IAM principal will be used for credentials.
• The Cloud SQL Admin API to be enabled within your Google Cloud Project. By default, the API will be called in the project associated with the IAM principal.

Credentials

This library uses the Application Default Credentials (ADC) strategy for resolving credentials. Please see these instructions for how to set your ADC (Google Cloud Application vs Local Development, IAM user vs service account credentials), or consult the google.auth package.

To explicitly set a specific source for the credentials, see Configuring the Connector below.

How to use this Connector

To connect to Cloud SQL using the connector, inititalize a Connector object and call it's connect method with the proper input parameters.

The Connector itself creates connection objects by calling its connect method but does not manage database connection pooling. For this reason, it is recommended to use the connector alongside a library that can create connection pools, such as SQLAlchemy. This will allow for connections to remain open and be reused, reducing connection overhead and the number of connections needed.

In the Connector's connect method below, input your connection string as the first positional argument and the name of the database driver for the second positional argument. Insert the rest of your connection keyword arguments like user, password and database. You can also set the optional timeout or ip_type keyword arguments.

To use this connector with SQLAlchemy, use the creator argument for sqlalchemy.create_engine:

from google.cloud.sql.connector import Connector
import sqlalchemy

# initialize Connector object
connector = Connector()

# function to return the database connection
def getconn() -> pymysql.connections.Connection:
    conn: pymysql.connections.Connection = connector.connect(
        "project:region:instance",
        "pymysql",
        user="my-user",
        password="my-password",
        db="my-db-name"
    )
    return conn

# create connection pool
pool = sqlalchemy.create_engine(
    "mysql+pymysql://",
    creator=getconn,
)

The returned connection pool engine can then be used to query and modify the database.

# insert statement
insert_stmt = sqlalchemy.text(
    "INSERT INTO my_table (id, title) VALUES (:id, :title)",
)

with pool.connect() as db_conn:
    # insert into database
    db_conn.execute(insert_stmt, parameters={"id": "book1", "title": "Book One"})

    # query database
    result = db_conn.execute(sqlalchemy.text("SELECT * from my_table")).fetchall()

    # Do something with the results
    for row in result:
        print(row)

To close the Connector object's background resources, call it's close() method as follows:

connector.close()

Note: For more examples of using SQLAlchemy to manage connection pooling with the connector, please see Cloud SQL SQLAlchemy Samples.

Note for SQL Server users: If your SQL Server instance requires SSL, you need to download the CA certificate for your instance and include cafile={path to downloaded certificate} and validate_host=False. This is a workaround for a known issue.

Configuring the Connector

If you need to customize something about the connector, or want to specify defaults for each connection to make, you can initialize a Connector object as follows:

from google.cloud.sql.connector import Connector, IPTypes

# Note: all parameters below are optional
connector = Connector(
    ip_type=IPTypes.PUBLIC,
    enable_iam_auth=False,
    timeout=30,
    credentials=custom_creds # google.auth.credentials.Credentials
)

Using Connector as a Context Manager

The Connector object can also be used as a context manager in order to automatically close and cleanup resources, removing the need for explicit calls to connector.close().

Connector as a context manager:

from google.cloud.sql.connector import Connector
import sqlalchemy

# build connection
def getconn() -> pymysql.connections.Connection:
    with Connector() as connector:
        conn = connector.connect(
            "project:region:instance",
            "pymysql",
            user="my-user",
            password="my-password",
            db="my-db-name"
        )
    return conn

# create connection pool
pool = sqlalchemy.create_engine(
    "mysql+pymysql://",
    creator=getconn,
)

# insert statement
insert_stmt = sqlalchemy.text(
    "INSERT INTO my_table (id, title) VALUES (:id, :title)",
)

# interact with Cloud SQL database using connection pool
with pool.connect() as db_conn:
    # insert into database
    db_conn.execute(insert_stmt, parameters={"id": "book1", "title": "Book One"})

    # query database
    result = db_conn.execute(sqlalchemy.text("SELECT * from my_table")).fetchall()

    # Do something with the results
    for row in result:
        print(row)

Specifying Public or Private IP

The Cloud SQL Connector for Python can be used to connect to Cloud SQL instances using both public and private IP addresses. To specify which IP address to use to connect, set the ip_type keyword argument Possible values are IPTypes.PUBLIC and IPTypes.PRIVATE. Example:

from google.cloud.sql.connector import IPTypes

connector.connect(
    "project:region:instance",
    "pymysql",
    ip_type=IPTypes.PRIVATE # use private IP
... insert other kwargs ...
)

Note: If specifying Private IP, your application must already be in the same VPC network as your Cloud SQL Instance.

IAM Authentication

Connections using Automatic IAM database authentication are supported when using Postgres or MySQL drivers. First, make sure to configure your Cloud SQL Instance to allow IAM authentication and add an IAM database user.

Now, you can connect using user or service account credentials instead of a password. In the call to connect, set the enable_iam_auth keyword argument to true and the user argument to the appropriately formatted IAM principal.

Postgres: For an IAM user account, this is the user's email address. For a service account, it is the service account's email without the .gserviceaccount.com domain suffix.

MySQL: For an IAM user account, this is the user's email address, without the @ or domain name. For example, for test-user@gmail.com, set the user argument to test-user. For a service account, this is the service account's email address without the @project-id.iam.gserviceaccount.com suffix.

Example:

connector.connect(
     "project:region:instance",
     "pg8000",
     user="postgres-iam-user@gmail.com",
     db="my-db-name",
     enable_iam_auth=True,
 )

SQL Server Active Directory Authentication

Active Directory authentication for SQL Server instances is currently only supported on Windows. First, make sure to follow these steps to set up a Managed AD domain and join your Cloud SQL instance to the domain. See here for more info on Cloud SQL Active Directory integration.

Once you have followed the steps linked above, you can run the following code to return a connection object:

connector.connect(
    "project:region:instance",
    "pytds",
    db="my-db-name",
    active_directory_auth=True,
    server_name="public.[instance].[location].[project].cloudsql.[domain]",
)

Or, if using Private IP:

connector.connect(
    "project:region:instance",
    "pytds",
    db="my-db-name",
    active_directory_auth=True,
    server_name="private.[instance].[location].[project].cloudsql.[domain]",
    ip_type=IPTypes.PRIVATE
)

Using the Python Connector with Python Web Frameworks

The Python Connector can be used alongside popular Python web frameworks such as Flask, FastAPI, etc, to integrate Cloud SQL databases within your web applications.

Flask-SQLAlchemy

Flask-SQLAlchemy is an extension for Flask that adds support for SQLAlchemy to your application. It aims to simplify using SQLAlchemy with Flask by providing useful defaults and extra helpers that make it easier to accomplish common tasks.

You can configure Flask-SQLAlchemy to connect to a Cloud SQL database from your web application through the following:

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from google.cloud.sql.connector import Connector, IPTypes


# Python Connector database connection function
def getconn():
    with Connector() as connector:
        conn = connector.connect(
            "project:region:instance-name", # Cloud SQL Instance Connection Name
            "pg8000",
            user="my-user",
            password="my-password",
            db="my-database",
            ip_type= IPTypes.PUBLIC  # IPTypes.PRIVATE for private IP
        )
        return conn


app = Flask(__name__)

# configure Flask-SQLAlchemy to use Python Connector
app.config['SQLALCHEMY_DATABASE_URI'] = "postgresql+pg8000://"
app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
    "creator": getconn
}

db = SQLAlchemy(app)

For more details on how to use Flask-SQLAlchemy, check out the Flask-SQLAlchemy Quickstarts

FastAPI

FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on standard Python type hints.

You can configure FastAPI to connect to a Cloud SQL database from your web application using SQLAlchemy ORM through the following:

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from google.cloud.sql.connector import Connector, IPTypes

# Python Connector database connection function
def getconn():
    with Connector() as connector:
        conn = connector.connect(
            "project:region:instance-name", # Cloud SQL Instance Connection Name
            "pg8000",
            user="my-user",
            password="my-password",
            db="my-database",
            ip_type= IPTypes.PUBLIC  # IPTypes.PRIVATE for private IP
        )
    return conn

SQLALCHEMY_DATABASE_URL = "postgresql+pg8000://"

engine = create_engine(
    SQLALCHEMY_DATABASE_URL , creator=getconn
)

# create SQLAlchemy ORM session
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

To learn more about integrating a database into your FastAPI application, follow along the FastAPI SQL Database guide.

Async Driver Usage

The Cloud SQL Connector is compatible with asyncio to improve the speed and efficiency of database connections through concurrency. You can use all non-asyncio drivers through the Connector.connect_async function, in addition to the following asyncio database drivers:

• asyncpg (Postgres)

The Cloud SQL Connector has a helper create_async_connector function that is recommended for asyncio database connections. It returns a Connector object that uses the current thread's running event loop. This is different than Connector() which by default initializes a new event loop in a background thread.

The create_async_connector allows all the same input arguments as the Connector object.

Once a Connector object is returned by create_async_connector you can call its connect_async method, just as you would the connect method:

import asyncio
import asyncpg
from google.cloud.sql.connector import create_async_connector


async def main():
    # intialize Connector object using 'create_async_connector'
    connector = await create_async_connector()

    # create connection to Cloud SQL database
    conn: asyncpg.Connection = await connector.connect_async(
        "project:region:instance",  # Cloud SQL instance connection name
        "asyncpg",
        user="my-user",
        password="my-password",
        db="my-db-name"
        # ... additional database driver args
    )

    # insert into Cloud SQL database (example)
    await conn.execute("INSERT INTO ratings (title, genre, rating) VALUES ('Batman', 'Action', 8.2)")

    # query Cloud SQL database (example)
    results = await conn.fetch("SELECT * from ratings")

    # ... do something with results
    for row in results:
        print(row)

    # close asyncpg connection
    await conn.close()

    # close Cloud SQL Connector
    await connector.close_async()


# Test connection with `asyncio`
asyncio.run(main())

For more details on interacting with an asyncpg.Connection, please visit the official documentation.

Async Context Manager

An alternative to using the create_async_connector function is initializing a Connector as an async context manager, removing the need for explicit calls to connector.close_async() to cleanup resources.

Note: This alternative requires that the running event loop be passed in as the loop argument to Connector().

import asyncio
import asyncpg
from google.cloud.sql.connector import Connector

async def main():
    # get current running event loop to be used with Connector
    loop = asyncio.get_running_loop()
    # intialize Connector object as async context manager
    async with Connector(loop=loop) as connector:

        # create connection to Cloud SQL database
        conn: asyncpg.Connection = await connector.connect_async(
            "project:region:instance",  # Cloud SQL instance connection name
            "asyncpg",
            user="my-user",
            password="my-password",
            db="my-db-name"
            # ... additional database driver args
        )

        # insert into Cloud SQL database (example)
        await conn.execute("INSERT INTO ratings (title, genre, rating) VALUES ('Batman', 'Action', 8.2)")

        # query Cloud SQL database (example)
        results = await conn.fetch("SELECT * from ratings")

        # ... do something with results
        for row in results:
            print(row)

        # close asyncpg connection
        await conn.close()

# Test connection with `asyncio`
asyncio.run(main())

Support policy

Major version lifecycle

This project uses semantic versioning, and uses the following lifecycle regarding support for a major version:

Active - Active versions get all new features and security fixes (that wouldn’t otherwise introduce a breaking change). New major versions are guaranteed to be "active" for a minimum of 1 year. Deprecated - Deprecated versions continue to receive security and critical bug fixes, but do not receive new features. Deprecated versions will be publicly supported for 1 year. Unsupported - Any major version that has been deprecated for >=1 year is considered publicly unsupported.

Supported Python Versions

We test and support at a minimum, every active version until it's end-of-life date. Changes in supported Python versions will be considered a minor change, and will be listed in the release notes.

Release cadence

This project aims for a minimum monthly release cadence. If no new features or fixes have been added, a new PATCH version with the latest dependencies is released.

Contributing

We welcome outside contributions. Please see our Contributing Guide for details on how best to contribute.