Connecting from GKE

This page describes how to set up a connection from an application running in Google Kubernetes Engine to a Cloud SQL instance, using the Cloud SQL Proxy Docker image.


To access a Cloud SQL instance from an application running in Google Kubernetes Engine, you use the Cloud SQL Proxy Docker image. The Cloud SQL Proxy is added to your pod using the "sidecar" container pattern—the proxy container is in the same pod as your application, which enables the application to connect to the proxy using localhost, increasing security and performance. Learn more.

For more information about the Cloud SQL Proxy, see About the Cloud SQL Proxy. For more information about working with pods, see Pod Overview in the Kubernetes documentation.

Before you begin

Before you start this procedure, you must have:

  • A GKE cluster running version 1.2 or higher, with the kubectl command-line tool installed and configured to communicate with the cluster.

    For help getting started with GKE, see the Quickstart.

  • An application container in a pod on the GKE cluster.

  • A PostgreSQL instance created.

    For help creating a Cloud SQL instance, see Creating Instances.

1. Enable the API

Enable the Cloud SQL Admin API.

Enable the API

2. Create a service account

The proxy requires a service account with the proper privileges for your Cloud SQL instance. For more information about service accounts, see the GCP Auth Guide.

  1. Go to the Cloud SQL Service accounts page of the Google Cloud Platform Console.

    Go to the Service accounts page

  2. If needed, select the project that contains your Cloud SQL instance.
  3. Click Create service account.
  4. In the Create service account dialog, provide a descriptive name for the service account.
  5. For Role, select one of the following roles:
    • Cloud SQL > Cloud SQL Client
    • Cloud SQL > Cloud SQL Editor
    • Cloud SQL > Cloud SQL Admin

    Alternatively, you can use the primitive Editor role by selecting Project > Editor, but the Editor role includes permissions across Google Cloud Platform.

    If you do not see these roles, your Google Cloud Platform user might not have the resourcemanager.projects.setIamPolicy permission. You can check your permissions by going to the IAM page in the Google Cloud Platform Console and searching for your user id.

  6. Change the Service account ID to a unique value that you will recognize so you can easily find this service account later if needed.
  7. Click Furnish a new private key.
  8. The default key type is JSON, which is the correct value to use.
  9. Click Create.

    The private key file is downloaded to your machine. You can move it to another location. Keep the key file secure.

You will provide the location of this key file later in this task, when you create your secrets, as PROXY_KEY_FILE_PATH.

3. Create your database user

If needed, create a PostgreSQL user that your application will use to access your database:

gcloud sql users create [DBUSER] --instance=[INSTANCE_NAME] --password=[PASSWORD]

For help with creating a user account, see Creating a user.

4. Get your instance connection name

The instance connection name identifies your Cloud SQL instance on Google Cloud Platform. You can get it from the Google Cloud Platform Console, or by using the gcloud command-line tool:

gcloud sql instances describe [INSTANCE_NAME]

For example, for the instance myinstance1 in project myproject1, the gcloud output would be:

connectionName: myproject1:us-central1:myinstance1

You will provide this value later as INSTANCE_CONNECTION_NAME.

5. Create your Secrets

You need two Secrets to enable your GKE application to access the data in your Cloud SQL instance:

  • The cloudsql-instance-credentials Secret contains the service account.
  • The cloudsql-db-credentials Secret provides the database` user account and password.

To create these Secrets:

  1. Create the cloudsql-instance-credentials Secret, using the key file you downloaded previously:

    kubectl create secret generic cloudsql-instance-credentials \
  2. Create the cloudsql-db-credentials Secret, using the name and password for the database user you created previously:

    kubectl create secret generic cloudsql-db-credentials \
        --from-literal=username=[DBUSER] --from-literal=password=[PASSWORD]

6. Update your pod configuration file

Your pod configuration file needs to include the host address of the database, the Secrets, and the location of your Cloud SQL instance.

The exact variable names needed depend on the application container you are using. For a complete sample deployment, including sample code, see sample Kubernetes Deployment manifest file on GitHub.

  1. Provide as the host address your application uses to access the database.

    Because the proxy runs in a second container in the same pod, it appears to your application as localhost, so you use to connect to it.

  2. Provide the cloudsql-db-credentials Secret to enable the application to log in to the database.

    For example, the following configuration provides the DB_USER and DB_PASSWORD environment variables to your application using the cloudsql-db-credentials Secret.

    - name: DB_USER
          name: cloudsql-db-credentials
          key: username
    - name: DB_PASSWORD
          name: cloudsql-db-credentials
          key: password

  3. In your Kubernetes Deployment file, define an additional container in the Pod definition to run the proxy container. This container exposes port 5432 and uses the instance connection name you recorded earlier.

    - name: cloudsql-proxy
      command: ["/cloud_sql_proxy",
        runAsUser: 2  # non-root user
        allowPrivilegeEscalation: false
        - name: cloudsql-instance-credentials
          mountPath: /secrets/cloudsql
          readOnly: true
    This step also defines the mount points for your container.

  4. Define your volumes:

      - name: cloudsql-instance-credentials
          secretName: cloudsql-instance-credentials

  5. Add a securityContext to your deployment file. This causes the Cloud SQL Proxy to run as a non-root user. You can provide any user id; using a different user than other sensitive workloads is a good practice.

      runAsUser: 2  # non-root user
      allowPrivilegeEscalation: false

  6. Bring up your Deployment using the Kubernetes manifest file:

    kubectl apply -f deployment.yaml

7. Update your application to connect to Cloud SQL

When you have your Google Kubernetes Engine environment set up, you connect to Cloud SQL the same way as any other external application that is using the proxy. The exact connection string you use depends on what language and framework you are using.

For some example connection strings, see Language-specific information and examples.

Need help? For help troubleshooting the proxy, see Troubleshooting Cloud SQL Proxy connections. Or, see our Cloud SQL Support page.

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