Database Access with Cloud SQL for PostgreSQL

Teleport can provide secure access to PostgreSQL on Google Cloud SQL via the Teleport Database Service. This allows for fine-grained access control through Teleport's RBAC.

In this guide, you will:

1. Configure your PostgreSQL on Google Cloud SQL database with a service account.
2. Add the database to your Teleport cluster.
3. Connect to the database via Teleport

How it works

The Teleport Database Service uses IAM authentication to communicate with PostgreSQL. When a user connects to the database via Teleport, the Teleport Database Service obtains Google Cloud credentials and authenticates to Google Cloud as an IAM principal with permissions to manage the database.

• Self-Hosted
• Cloud-Hosted

Prerequisites

• A running Teleport cluster version 15.4.4 or above. If you want to get started with Teleport, sign up for a free trial or set up a demo environment.

• The tctl admin tool and tsh client tool.

  On Teleport Enterprise, you must use the Enterprise version of tctl, which you can download from your Teleport account workspace. Otherwise, visit Installation for instructions on downloading tctl and tsh for Teleport Community Edition.

• Google Cloud account
• Command-line client psql installed and added to your system's PATH environment variable.
• A host, e.g., a Compute Engine instance, where you will run the Teleport Database Service
• To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials. tctl is supported on macOS and Linux machines. For example:

  tsh login --proxy=teleport.example.com --user=email@example.com
  tctl status
  Cluster  teleport.example.com
  Version  15.4.4
  CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

  If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.

Step 1/9. Create a service account for the Teleport Database Service

A GCP service account will be used by the Teleport Database Service to create ephemeral access tokens for other GCP service accounts when it's acting on the behalf of authorized Teleport users.

Create a service account

Go to the Service Accounts page and create a service account:

(Optional) Grant permissions

The Teleport Database Service needs permissions to automatically download your Cloud SQL instance's root CA certificate and to general an ephemeral client certificate.

If you intend to download the CA certificate manually and your Cloud SQL instance SSL mode is not "require trusted client certificates", then you can skip this step.

Otherwise, in the second step of the service account creation dialogue, assign the service account the pre-defined GCP IAM role "Cloud SQL Client", then click "Done".

# Used to auto-download the instance's root CA certificate and check SSL mode.
cloudsql.instances.get
# Used to generate an ephemeral client certificate
cloudsql.instances.connect

Step 2/9. Create a service account for a database user

Teleport uses service accounts to connect to Cloud SQL databases.

Create a service account

Go to the IAM & Admin Service Accounts page and create a new service account named "cloudsql-user":

Click "Create and continue".

Grant permissions

On the second step grant this service account the "Cloud SQL Instance User" role which will allow it to connect to Cloud SQL instances using an IAM token for authentication:

Click "Done".

Grant access to the service account

The Teleport Database Service must be able to impersonate this service account. Navigate to the "cloudsql-user" service account overview page and select the "permissions" tab:

Click "Grant Access" and add the "teleport-db-service" principal ID. Select the "Service Account Token Creator" role and save the change:

# Used to generate IAM auth tokens when connecting to a database instance.
iam.serviceAccounts.getAccessToken

Step 3/9. Configure your Cloud SQL database

Teleport uses IAM database authentication with Cloud SQL PostgreSQL instances.

If you're creating a new PostgreSQL instance, make sure to add the cloudsql.iam_authentication database flag under "Customize your instance / Flags" section:

To check whether IAM authentication is enabled for an existing Cloud SQL instance, look for the flag on the Configuration panel on the instance's Overview page:

If it isn't enabled, you can add this flag using the "Edit configuration" dialog at the bottom of the Configuration panel. Changing this setting may require a database instance reboot.

Create a database user

Now go back to the Users page of your Cloud SQL instance and add a new user account. In the sidebar, choose "Cloud IAM" authentication type and add the "cloudsql-user" service account that you created in the second step:

Press "Add" and your Users table should look similar to this:

See Creating and managing IAM users in Google Cloud documentation for more info.

Step 4/9. Install Teleport

Install Teleport on your Linux server:

1. Assign edition to one of the following, depending on your Teleport edition:

   Edition	Value
   Teleport Enterprise Cloud	cloud
   Teleport Enterprise (Self-Hosted)	enterprise
   Teleport Community Edition	oss

2. Get the version of Teleport to install. If you have automatic agent updates enabled in your cluster, query the latest Teleport version that is compatible with the updater:

   TELEPORT_DOMAIN=example.teleport.com
   TELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/automaticupgrades/channel/default/version | sed 's/v//')"

   Otherwise, get the version of your Teleport cluster:

   TELEPORT_DOMAIN=example.teleport.com
   TELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/ping | jq -r '.server_version')"

3. Install Teleport on your Linux server:

   curl https://goteleport.com/static/install.sh | bash -s ${TELEPORT_VERSION} edition

   The installation script detects the package manager on your Linux server and uses it to install Teleport binaries. To customize your installation, learn about the Teleport package repositories in the installation guide.

Step 5/9. Configure the Teleport Database Service

Create a join token

The Database Service requires a valid join token to join your Teleport cluster. Run the following tctl command and save the token output in /tmp/token on the server that will run the Database Service:

tctl tokens add --type=db --format=text

(Optional) Download the Cloud SQL CA certificate

The Cloud SQL instance's root CA certificate is required so that the Teleport Database Service can validate the certificate presented by the database instance.

The Teleport Database Service can automatically download the instance's root CA certificate if it is granted the "cloudsql.instances.get" permission.

Alternatively, you can download the instance's CA certificate file from the "Connections" tab under the "Security" section:

Generate Teleport config

sudo teleport db configure create \   -o file \   --name=cloudsql \   --protocol=postgres \   --labels=env=dev \   --token=/tmp/token \   --proxy=example.teleport.sh:443  \   --uri=public-ip:5432 \   --gcp-project-id=project-id \   --gcp-instance-id=instance-id 

sudo teleport db configure create \   -o file \   --name=cloudsql \   --protocol=postgres \   --labels=env=dev \   --token=/tmp/token \   --proxy=example.teleport.sh:443  \   --uri=public-ip:5432 \   --gcp-project-id=project-id \   --gcp-instance-id=instance-id \   --ca-cert-file=/path/to/cloudsql/instance/server-ca.pem 

This command will generate a Teleport Database Service configuration file and save it to /etc/teleport.yaml.

Step 6/9. Configure GCP credentials

The Teleport Database Service must have credentials for the "teleport-db-service" GCP service account.

If the Teleport Database Service is hosted on a GCE instance, you can change the attached service account. For non-GCE deployments of Teleport, we recommend using workload identity.

Alternatively, go to that service account's Keys tab and create a new key:

Make sure to choose JSON format:

Save the file. Set the GOOGLE_APPLICATION_CREDENTIALS environment variable to point to the JSON credentials file you downloaded earlier. For example, if you use systemd to start teleport, then you should edit the service's EnvironmentFile to include the env var:

echo 'GOOGLE_APPLICATION_CREDENTIALS=/path/to/credentials.json' | sudo tee -a /etc/default/teleport

Step 7/9. Start the Teleport Database Service

Configure the Teleport Database Service to start automatically when the host boots up by creating a systemd service for it. The instructions depend on how you installed the Teleport Database Service.

sudo systemctl enable teleport
sudo systemctl start teleport

sudo teleport install systemd -o /etc/systemd/system/teleport.service
sudo systemctl enable teleport
sudo systemctl start teleport

You can check the status of the Teleport Database Service with systemctl status teleport and view its logs with journalctl -fu teleport.

Step 8/9. Create a Teleport user

tctl users add \  --roles=access \  --db-users="*" \  --db-names="*" \  alice

tctl users add \  --roles=access,requester \  --db-users="*" \  --db-names="*" \  alice

For more detailed information about database access controls and how to restrict access see RBAC documentation.

Step 9/9. Connect

Once the Database Service has joined the cluster, log in to see the available databases:

tsh login --proxy=teleport.example.com --user=alice
tsh db ls
Name     Description              Labels
-------- ------------------------ --------
cloudsql GCP Cloud SQL PostgreSQL env=dev

tsh login --proxy=mytenant.teleport.sh --user=alice
tsh db ls
Name     Description              Labels
-------- ------------------------ --------
cloudsql GCP Cloud SQL PostgreSQL env=dev

When connecting to the database, use the name of the database's service account that you added as an IAM database user above, minus the ".gserviceaccount.com" suffix. The database user name is shown on the Users page of your Cloud SQL instance. Retrieve credentials for the "cloudsql" example database and connect to it:

tsh db connect --db-user=cloudsql-user@project-id.iam --db-name=postgres cloudsql

To log out of the database and remove credentials:

Remove credentials for a particular database instance:
tsh db logout cloudsql
Or remove credentials for all databases:
tsh db logout

Troubleshooting

Could not find default credentials

This error can come from either your client application or Teleport.

For a client application, ensure that you disable GCP credential loading. Your client should not attempt to load credentials because GCP credentials will be provided by the Teleport Database Service.

If you see the credentials error message in the Teleport Database Service logs (at DEBUG log level), then the Teleport Database Service does not have GCP credentials configured correctly.

If you are using a service account key, then ensure that the environment variable GOOGLE_APPLICATION_CREDENTIALS=/path/to/credentials.json is set and restart your Teleport Database Service to ensure that the env var is available to teleport. For example, if your Teleport Database Service runs as a systemd service:

echo 'GOOGLE_APPLICATION_CREDENTIALS=/path/to/credentials.json' | sudo tee -a /etc/default/teleport
sudo systemctl restart teleport

See authentication in the Google Cloud documentation for more information about service account authentication methods.

Unable to cancel a query

If you use a PostgreSQL cli client like psql, and you try to cancel a query with ctrl+c, but it doesn't cancel the query, then you need to connect using a tsh local proxy instead. When psql cancels a query, it establishes a new connection without TLS certificates, however Teleport requires TLS certificates not only for authentication, but also to route database connections.

If you enable TLS Routing in Teleport then tsh db connect will automatically start a local proxy for every connection. Alternatively, you can connect via Teleport Connect which also uses a local proxy. Otherwise, you need to start a tsh local proxy manually using tsh proxy db and connect via the local proxy.

If you have already started a long-running query in a psql session that you cannot cancel with ctrl+c, you can start a new client session to cancel that query manually:

First, find the query's process identifier (PID):

SELECT pid,usename,backend_start,query FROM pg_stat_activity WHERE state = 'active';

Next, gracefully cancel the query using its PID. This will send a SIGINT signal to the postgres backend process for that query:

SELECT pg_cancel_backend(<PID>);

You should always try to gracefully terminate a query first, but if graceful cancellation is taking too long, then you can forcefully terminate the query instead. This will send a SIGTERM signal to the postgres backend process for that query:

SELECT pg_terminate_backend(<PID>);

See the PostgreSQL documentation on admin functions for more information about the pg_cancel_backend and pg_terminate_backend functions.

SSL SYSCALL error

You may encounter the following error when your local psql is not compatible with newer versions of OpenSSL:

tsh db connect --db-user postgres --db-name postgres postgres
psql: error: connection to server at "localhost" (::1), port 12345 failed: Connection refused    Is the server running on that host and accepting TCP/IP connections?connection to server at "localhost" (127.0.0.1), port 12345 failed: SSL SYSCALL error: Undefined error: 0

Please upgrade your local psql to the latest version.

Next steps

• Learn how to restrict access to certain users and databases.

• View the High Availability (HA) guide.

• Take a look at the YAML configuration reference.

• See the full CLI reference.

• Learn more about authenticating as a service account in Google Cloud.