Connecting to Cloud SQL - MySQL

Before you begin

If you haven't already, set up a Node.js Development Environment by following the Node.js setup guide and create a project.
Create a Cloud SQL Instance by following these instructions. Note the instance connection name, database user, and database password that you create.
Create a database for your application by following these instructions. Note the database name.
Set up Application Default Credentials
Use the information noted in the previous steps:

export INSTANCE_CONNECTION_NAME='<MY-PROJECT>:<INSTANCE-REGION>:<INSTANCE-NAME>'
export DB_USER='my-db-user'
export DB_PASS='my-db-pass'
export DB_NAME='my_db'

Note: Defining credentials in environment variables is convenient, but not secure. For a more secure solution, use Secret Manager to help keep secrets safe. You can then define export CLOUD_SQL_CREDENTIALS_SECRET='projects/PROJECT_ID/secrets/SECRET_ID/versions/VERSION' to reference a secret that stores your Cloud SQL database password. The sample app checks for your defined secret version. If a version is present, the app retrieves the DB_PASS from Secret Manager before it connects to Cloud SQL.

Running locally

To run this application locally, download and install the cloud_sql_proxy by following the instructions.

Instructions are provided below for using the proxy with a TCP connection or a Unix Domain Socket. On Linux or Mac OS you can use either option, but on Windows the proxy currently requires a TCP connection.

Launch proxy with TCP

To run the sample locally with a TCP connection, set environment variables and launch the proxy as shown below.

Linux / Mac OS

Use these terminal commands to initialize environment variables:

export INSTANCE_HOST='127.0.0.1'
export DB_PORT='3306'
export DB_USER='<DB_USER_NAME>'
export DB_PASS='<DB_PASSWORD>'
export DB_NAME='<DB_NAME>'

Then use this command to launch the proxy in the background:

./cloud-sql-proxy --port=3306 "$INSTANCE_CONNECTION_NAME" &

Windows/PowerShell

Use these PowerShell commands to initialize environment variables:

$env:INSTANCE_HOST="127.0.0.1"
$env:DB_PORT="3306"
$env:DB_USER="<DB_USER_NAME>"
$env:DB_PASS="<DB_PASSWORD>"
$env:DB_NAME="<DB_NAME>"

Then use this command to launch the proxy in a separate PowerShell session:

Start-Process -filepath "C:\<path to proxy exe>" -ArgumentList "<project-id>:<region>:<instance-name> --port=3306"

Launch proxy with Unix Domain Socket

NOTE: this option is currently only supported on Linux and Mac OS. Windows users should use the Launch proxy with TCP option.

To use a Unix socket, you'll need to create a directory and give write access to the user running the proxy. For example:

sudo mkdir ./cloudsql
sudo chown -R $USER ./cloudsql

Use these terminal commands to initialize other environment variables as well:

export INSTANCE_UNIX_SOCKET='./cloudsql/<MY-PROJECT>:<INSTANCE-REGION>:<INSTANCE-NAME>'
export DB_USER='<DB_USER_NAME>'
export DB_PASS='<DB_PASSWORD>'
export DB_NAME='<DB_NAME>'

Then use this command to launch the proxy in the background:

./cloud-sql-proxy --unix-socket=./cloudsql "$INSTANCE_CONNECTION_NAME" &

Testing the application

Next, setup install the requirements with npm:

npm install

Finally, start the application:

npm start

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

Google App Engine Standard

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

First, update app.standard.yaml with the correct values to pass the environment variables into the runtime.

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

gcloud app deploy app.standard.yaml

To launch your browser and view the app at https://[YOUR_PROJECT_ID].appspot.com, run the following command:

gcloud app browse

Deploy to Google App Engine Flexible

First, update app.flexible.yaml with the correct values to pass the environment variables into the runtime.

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

gcloud app deploy app.flexible.yaml

To launch your browser and view the app at https://[YOUR_PROJECT_ID].appspot.com, run the following command:

gcloud app browse

Deploy to Cloud Run

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

Build the container image:

gcloud builds submit --tag gcr.io/[YOUR_PROJECT_ID]/run-sql

Deploy the service to Cloud Run:

gcloud run deploy run-sql --image gcr.io/[YOUR_PROJECT_ID]/run-sql

Take note of the URL output at the end of the deployment process.

Configure the service for use with Cloud Run

gcloud run services update run-sql \
    --add-cloudsql-instances [INSTANCE_CONNECTION_NAME] \
    --set-env-vars INSTANCE_UNIX_SOCKET=[INSTANCE_UNIX_SOCKET],\
      DB_USER=[MY_DB_USER],DB_PASS=[MY_DB_PASS],DB_NAME=[MY_DB]

Replace environment variables with the correct values for your Cloud SQL instance configuration.

This step can be done as part of deployment but is separated for clarity.

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_UNIX_SOCKET | \
    gcloud secrets create [INSTANCE_UNIX_SOCKET_SECRET] --data-file=-

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

gcloud beta run deploy SERVICE --image gcr.io/[YOUR_PROJECT_ID]/run-sql \
    --add-cloudsql-instances $INSTANCE_CONNECTION_NAME \
    --update-secrets INSTANCE_UNIX_SOCKET=[INSTANCE_UNIX_SOCKET_SECRET]:latest,\
      DB_USER=[DB_USER_SECRET]:latest, \
      DB_PASS=[DB_PASS_SECRET]:latest, \
      DB_NAME=[DB_NAME_SECRET]:latest

Navigate your browser to the URL noted in step 2.

For more details about using Cloud Run see http://cloud.run. Review other Node.js on Cloud Run samples.

Deploy to Cloud Functions

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

gcloud functions deploy votes --gen2 --runtime nodejs18 --trigger-http \
  --allow-unauthenticated \
  --entry-point votes \
  --region <INSTANCE_REGION> \
  --set-env-vars INSTANCE_UNIX_SOCKET=/cloudsql/<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

Note: If the function fails to deploy or returns a 500: Internal service error, this may be due to a known limitation with Cloud Functions gen2 not being able to configure the underlying Cloud Run service with a Cloud SQL connection.

A workaround command to fix this is is to manually revise the Cloud Run service with the Cloud SQL Connection:

gcloud run deploy votes --source . \
  --region <INSTANCE_REGION> \
  --add-cloudsql-instances <PROJECT_ID>:<INSTANCE_REGION>:<INSTANCE_NAME>

The Cloud Function command above can now be re-run with a successful deployment.