This demo application can be used to connect to Cloud SQL in two different ways:

1. The Cloud SQL Python Connector (recommended)

2. The Cloud SQL Auth Proxy

Using the Cloud SQL Python Connector library is recommended over the Cloud SQL Auth Proxy as it provides all the same functionality and features but as a native Python package. See cloud-sql-python-connector package.

1. If you haven't already, set up a Python Development Environment by following the python setup guide and create a project.

2. Create a 2nd Gen Cloud SQL Instance by following these instructions. Note the connection string, database user, and database password that you create.

3. Create a database for your application by following these instructions. Note the database name.

4. Create a service account with the 'Cloud SQL Client' permissions by following these instructions. Download a JSON key to use to authenticate your connection.

To run the demo application locally using the Cloud SQL Python Connector, set environment variables and install dependencies as shown below.

Note: The INSTANCE_CONNECTION_NAME for your instance can be found on the Overview page for your instance in the Google Cloud console or by running the following command:

gcloud sql instances describe <INSTANCE_NAME> --format='value(connectionName)'

Use these terminal commands to initialize environment variables:

export GOOGLE_APPLICATION_CREDENTIALS='/path/to/service/account/key.json'
export INSTANCE_CONNECTION_NAME='<PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>'
export DB_USER='<YOUR_DB_USER_NAME>'
export DB_PASS='<YOUR_DB_PASSWORD>'
export DB_NAME='<YOUR_DB_NAME>'

Note: Saving credentials in environment variables is convenient, but not secure - consider a more secure solution such as Secret Manager to help keep secrets safe.

Use these PowerShell commands to initialize environment variables:

$env:GOOGLE_APPLICATION_CREDENTIALS="/path/to/service/account/key.json"
$env:INSTANCE_CONNECTION_NAME="<PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>"
$env:DB_USER="<YOUR_DB_USER_NAME>"
$env:DB_PASS="<YOUR_DB_PASSWORD>"
$env:DB_NAME="<YOUR_DB_NAME>"

Note: Saving credentials in environment variables is convenient, but not secure - consider a more secure solution such as Secret Manager to help keep secrets safe.

Next, install the requirements into a virtual environment:

virtualenv --python python3 env
source env/bin/activate
pip install -r requirements.txt

Finally, start the application:

python app.py

Navigate towards http://127.0.0.1:8080 to verify your application is running correctly.

To run on GAE-Standard, create an App Engine project by following the setup with these instructions.

Update app.standard.yaml with the correct values to pass the environment variables into the runtime. Your app.standard.yaml file should look like this:

Note: If you want to connect to Cloud SQL over Private IP, add the additional env variable PRIVATE_IP: True below.

runtime: python310
entrypoint: gunicorn -b :$PORT app:app

env_variables:
  INSTANCE_CONNECTION_NAME: <PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>
  DB_USER: <YOUR_DB_USER_NAME>
  DB_PASS: <YOUR_DB_PASSWORD>
  DB_NAME: <YOUR_DB_NAME>

Note: Saving credentials in environment variables is convenient, but not secure - consider a more secure solution such as Secret Manager to help keep secrets safe.

Next, the following command will deploy the application to your Google Cloud project:

gcloud app deploy app.standard.yaml

To run on GAE-Flexible, create an App Engine project by following the setup for these instructions.

First, update app.flexible.yaml with the correct values to pass the environment variables into the runtime. Your app.flexible.yaml file should look like this:

Note: If you want to connect to Cloud SQL over Private IP, add the additional env variable PRIVATE_IP: True below.

runtime: custom
env: flex
entrypoint: gunicorn -b :$PORT app:app

env_variables:
  INSTANCE_CONNECTION_NAME: <PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>
  DB_USER: <YOUR_DB_USER_NAME>
  DB_PASS: <YOUR_DB_PASSWORD>
  DB_NAME: <YOUR_DB_NAME>

Note: Saving credentials in environment variables is convenient, but not secure - consider a more secure solution such as Secret Manager to help keep secrets safe.

Next, the following command will deploy the application to your Google Cloud project:

gcloud app deploy app.flexible.yaml

See the Cloud Run documentation for more details on connecting a Cloud Run service to Cloud SQL.

Note: If you want to connect to Cloud SQL over Private IP, add the additional env variable --set-env-vars PRIVATE_IP=True and flag --vpc-connector <YOUR_VPC_CONNECTOR> below.

gcloud run deploy cloud-sql-demo \
  --allow-unauthenticated \
  --set-env-vars INSTANCE_CONNECTION_NAME='<PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>' \
  --set-env-vars DB_USER='<YOUR_DB_USER_NAME>' \
  --set-env-vars DB_PASS='<YOUR_DB_PASSWORD>' \
  --set-env-vars DB_NAME='<YOUR_DB_NAME>'

Navigate your browser to the URL output at the end of the deployment process to view the demo app!

It is recommended to use the Secret Manager integration for Cloud Run instead of using environment variables for the SQL configuration. The service injects the SQL credentials from Secret Manager at runtime via an environment variable.

Create secrets via the command line:

echo -n $INSTANCE_CONNECTION_NAME | \
    gcloud secrets create [INSTANCE_CONNECTION_NAME_SECRET] --data-file=-

Deploy the service to Cloud Run specifying the env var name and secret name:

gcloud run deploy cloud-sql-demo \
  --allow-unauthenticated \
  --update-secrets INSTANCE_CONNECTION_NAME=[INSTANCE_CONNECTION_NAME_SECRET]:latest,\
    DB_USER=[DB_USER_SECRET]:latest, \
    DB_PASS=[DB_PASS_SECRET]:latest, \
    DB_NAME=[DB_NAME_SECRET]:latest

To deploy the service to Cloud Functions run the following command:

Note: If you want to connect to Cloud SQL over Private IP, add the additional env variable --set-env-vars PRIVATE_IP=True and flag --vpc-connector <YOUR_VPC_CONNECTOR> below.

gcloud functions deploy votes --gen2 --runtime python310 --trigger-http \
  --allow-unauthenticated \
  --entry-point votes \
  --region <INSTANCE_REGION> \
  --set-env-vars INSTANCE_CONNECTION_NAME=<PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME> \
  --set-env-vars DB_USER=$DB_USER \
  --set-env-vars DB_PASS=$DB_PASS \
  --set-env-vars DB_NAME=$DB_NAME

Take note of the URL output at the end of the deployment process to view your function!