Database Access with PostgreSQL on GCP Cloud SQL

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 an PostgreSQL on Google Cloud SQL with a service account.
2. Join the PostgreSQL on Google Cloud SQL database to your Teleport cluster.
3. Connect to the PostgreSQL on Google Cloud SQL database via the Teleport Database Service.

• Self-Hosted
• Teleport Enterprise Cloud

Prerequisites

• A running Teleport cluster. 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 version >= 15.2.2.

  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 protected]
  tctl status
  Cluster  teleport.example.com
  Version  15.2.2
  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 1/7. Enable Cloud SQL IAM authentication

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.

Step 2/7. 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:

Press "Create".

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 IAM token for authentication:

Press "Done".

Configure authentication for your service account

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 service account you've just created:

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 3/7. Create a service account for the Teleport Database Service

The final part of GCP configuration is to create a service account for the Teleport Database Service.

Create a service account

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

Grant permissions

Assign the Service Account the following IAM roles:

• "Service Account Token Creator" will allow the Database Service to generate IAM authentication tokens when connecting to the database as the service account user we created above.
• Either "Cloud SQL Viewer" or "Cloud SQL Admin":
  • "Cloud SQL Viewer" will allow the Database Service to automatically download your Cloud SQL instance's root CA certificate, but does not support client certificate authentication.
  • "Cloud SQL Admin" will allow the Database Service to automatically download your Cloud SQL instance's root CA certificate and generate an ephemeral client certificate when the GCP instance is configured to "Allow only SSL connections."

Assign it the "Service Account Token Creator" role:

# Used to generate IAM auth tokens when connecting to a database instance.
iam.serviceAccounts.getAccessToken
# Used to auto-download the instance's root CA certificate.
cloudsql.instances.get

(Optional) Allow only SSL connections

If you intend to use "Allow only SSL connections" option on your Cloud SQL database, the service account must include the following permission to be able to generate ephemeral client certificates:

cloudsql.sslCerts.createEphemeral

GCP does not currently support granting this permission to custom roles so you'd need to assign "Cloud SQL Admin" role to the Teleport service account.

Note that "Allow only SSL connections" setting only forces the client to provide a client certificate - all communication between Teleport and the database is still over TLS even with this setting disabled.

(Optional) Create a key for the service account

You can directly attach the service account to a VM.

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

Make sure to choose JSON format:

Save the file. Your Teleport Database Service will need to use it as GCP application credentials file.

Step 4/7. Gather Cloud SQL instance information

To connect a Cloud SQL database to Teleport, you'll need to gather a few pieces of information about the instance.

• GCP Project ID.

You can normally see it in the organization view at the top of the GCP dashboard.

• Cloud SQL instance ID.

The instance ID is the name of your Cloud SQL instance shown at the top of the Overview page:

• Cloud SQL instance endpoint.

You will use the instance's public IP address to connect to it. It can be viewed on the "Connect to this instance" panel on the Overview page:

• (Optional) Cloud SQL instance root certificate.

The instance's root certificate is required so Teleport can validate the certificate presented by the database instance.

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

Alternatively, you can download server-ca.pem file from the Connections tab under Security section:

Step 5/7. 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 6/7. Set up the Teleport Database Service

The Database Service requires a valid auth token to connect to the cluster. Generate one by running the following command against your Teleport Auth Service and save it in /tmp/token on the node that will run the Database Service:

tctl tokens add --type=db

Install Teleport on the host where you will run the Teleport Database Service:

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.

Below is an example of a Database Service configuration file that proxies a single Cloud SQL PostgreSQL database. Save this to /etc/teleport.yaml:

version: v3
teleport:
  data_dir: /var/lib/teleport
  nodename: test
  # Proxy address to connect to. Note that it has to be the proxy address
  # because the Database Service always connects to the cluster over a reverse
  # tunnel.
  proxy_server: teleport.example.com:443
  auth_token: "/tmp/token"
db_service:
  enabled: "yes"
  # This section contains definitions of all databases proxied by this
  # service, can contain multiple items.
  databases:
    # Name of the database proxy instance, used to reference in CLI.
  - name: "cloudsql"
    # Free-form description of the database proxy instance.
    description: "GCP Cloud SQL PostgreSQL"
    # Database protocol.
    protocol: "postgres"
    # Database endpoint. For Cloud SQL use instance's public IP address.
    uri: "35.1.2.3:5432"
    # (Optional) path to Cloud SQL instance root certificate you downloaded
    # manually above.
    ca_cert_file: /path/to/cloudsql/instance/root.pem
    # GCP specific configuration when connecting Cloud SQL instance.
    gcp:
      # GCP project ID.
      project_id: "<project-id>"
      # Cloud SQL instance ID.
      instance_id: "test"
    # Labels to assign to the database, used in RBAC.
    static_labels:
      env: dev
auth_service:
  enabled: "no"
ssh_service:
  enabled: "no"
proxy_service:
  enabled: "no"

version: v3
teleport:
  data_dir: /var/lib/teleport
  nodename: test
  # Proxy address to connect to. Use your Teleport Cloud tenant address here.
  proxy_server: mytenant.teleport.sh:443
  auth_token: "/tmp/token"
db_service:
  enabled: "yes"
  # This section contains definitions of all databases proxied by this
  # service, can contain multiple items.
  databases:
    # Name of the database proxy instance, used to reference in CLI.
  - name: "cloudsql"
    # Free-form description of the database proxy instance.
    description: "GCP Cloud SQL PostgreSQL"
    # Database protocol.
    protocol: "postgres"
    # Database endpoint. For Cloud SQL use instance's public IP address.
    uri: "35.1.2.3:5432"
    # (Optional) path to Cloud SQL instance root certificate you downloaded
    # manually above.
    ca_cert_file: /path/to/cloudsql/instance/root.pem
    # GCP specific configuration when connecting Cloud SQL instance.
    gcp:
      # GCP project ID.
      project_id: "<project-id>"
      # Cloud SQL instance ID.
      instance_id: "test"
    # Labels to assign to the database, used in RBAC.
    static_labels:
      env: dev
auth_service:
  enabled: "no"
ssh_service:
  enabled: "no"
proxy_service:
  enabled: "no"

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.

GCP credentials

The Teleport Database Service must have credentials for the teleport-db-service GCP service account we created in step 3.

If the Teleport Database Service is hosted on a VM, you can change the attached service account.

Alternatively, set the GOOGLE_APPLICATION_CREDENTIALS environment variable to point to the JSON credentials file you downloaded earlier. If you are using systemd to start teleport, then you should edit the service's EnvironmentFile to include the following env var:

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

Step 7/7. 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

Note that you will only be able to see databases your role has access to. See our RBAC guide for more details.

To retrieve credentials for a database and connect to it:

tsh db connect --db-user=teleport@<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
Remove credentials for all database instances.
tsh db logout

Troubleshooting

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.