SQL database instances should only use private IP addresses

Description:

Datadog recommends configuring the second generation SQL instance to use private IPs instead of public IPs.

Rationale:

To lower the organization’s attack surface, ensure your Cloud SQL databases does not have public IPs. Private IPs provide improved network security and lower latency for your application.

Impact:

Removing the public IP address on SQL instances may break applications that relied on it for database connectivity.

Remediation:

From the console

  1. Go to the Cloud SQL Instances page in the Google Cloud Console: https://console.cloud.google.com/sql/instances
  2. Click the instance name to open its Instance details page.
  3. Select the Connections tab.
  4. Deselect the Public IP checkbox.
  5. Click Save to update the instance.

From the command line

  1. For every instance, remove the public IP and assign a private IP instead:

    gcloud sql instances patch <INSTANCE_NAME> --network=<VPC_NETWORK_NAME> --no-assign-ip

  2. Confirm the changes using the following command:

    gcloud sql instances describe <INSTANCE_NAME>

Prevention:

To prevent new SQL instances from getting configured with public IP addresses, set up a Restrict Public IP access on Cloud SQL instances Organization policy at:

https://console.cloud.google.com/iam-admin/orgpolicies/sql-restrictPublicIp

Default value:

By default, Cloud Sql instances have a public IP.

References:

  1. https://cloud.google.com/sql/docs/mysql/configure-private-ip
  2. https://cloud.google.com/sql/docs/mysql/private-ip
  3. https://cloud.google.com/resource-manager/docs/organization-policy/org-policy-constraints
  4. https://console.cloud.google.com/iam-admin/orgpolicies/sql-restrictPublicIp

Additional information:

Replicas inherit their private IP status from their primary instance. You cannot configure a private IP directly on a replica.