Database Access with Self-Hosted PostgreSQL

Teleport can provide secure access to PostgreSQL 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 database with mutual TLS authentication.
2. Join the PostgreSQL database to your Teleport cluster.
3. Connect to the PostgreSQL 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.

• A self-hosted PostgreSQL instance.
• Command-line client psql installed and added to your system's PATH environment variable.
• A host, e.g., an Amazon EC2 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 1/5. Create a Teleport token and user

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

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 2/5. Create a certificate/key pair

Teleport uses mutual TLS authentication with self-hosted databases. These databases must be configured with Teleport's certificate authority to be able to verify client certificates. They also need a certificate/key pair that Teleport can verify.

If you are using Teleport Cloud, your Teleport user must be allowed to impersonate the system role Db in order to be able to generate the database certificate.

Include the following allow rule in in your Teleport Cloud user's role:

allow:
  impersonate:
    users: ["Db"]
    roles: ["Db"]

Create the secrets:

Export Teleport's certificate authority and a generate certificate/key pair
for host db.example.com with a 3-month validity period.
tctl auth sign --format=db --host=db.example.com --out=server --ttl=2190h

In this example, db.example.com is the hostname where the Teleport Database Service can reach the PostgreSQL server.

The command will create 3 files: server.cas, server.crt and server.key which you'll need to enable mutual TLS on your PostgreSQL server.

Step 3/5. Configure your PostgreSQL server

To configure your PostgreSQL server to accept TLS connections, add the following to the PostgreSQL configuration file, postgresql.conf:

ssl = on
ssl_cert_file = '/path/to/server.crt'
ssl_key_file = '/path/to/server.key'
ssl_ca_file = '/path/to/server.cas'

See Secure TCP/IP Connections with SSL in the PostgreSQL documentation for more details.

Additionally, PostgreSQL should be configured to require client certificate authentication from clients connecting over TLS. This can be done by adding the following entries to PostgreSQL's host-based authentication file pg_hba.conf:

hostssl all             all             ::/0                    cert
hostssl all             all             0.0.0.0/0               cert

You should also ensure that you have no higher-priority md5 authentication rules that will match, otherwise PostgreSQL will offer them first, and the certificate-based Teleport login will fail.

See The pg_hba.conf File in the PostgreSQL documentation for more details.

Step 4/5. Configure and Start the Database Service

Install and configure Teleport where you will run the Teleport Database Service:

sudo teleport db configure create \   -o file \   --token=/tmp/token \   --proxy=teleport.example.com:443 \   --name=example-postgres \   --protocol=postgres \   --uri=postgres.example.com:5432 \   --labels=env=dev 

sudo teleport db configure create \   -o file \   --token=/tmp/token \   --proxy=mytenant.teleport.sh:443 \   --name=example-postgres \   --protocol=postgres \   --uri=postgres.example.com:5432 \   --labels=env=dev

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

helm repo add teleport https://charts.releases.teleport.dev

helm repo update

JOIN_TOKEN=$(cat /tmp/token)
helm install teleport-kube-agent teleport/teleport-kube-agent \  --create-namespace \  --namespace teleport-agent \  --set roles=db \  --set proxyAddr=teleport.example.com:443 \  --set authToken=${JOIN_TOKEN?} \  --set "databases[0].name=example-postgres" \  --set "databases[0].uri=postgres.example.com:5432" \  --set "databases[0].protocol=postgres" \  --set "labels.env=dev" \  --version 15.2.2

JOIN_TOKEN=$(cat /tmp/token)
helm install teleport-kube-agent teleport/teleport-kube-agent \  --create-namespace \  --namespace teleport-agent \  --set roles=db \  --set proxyAddr=mytenant.teleport.sh:443 \  --set authToken=${JOIN_TOKEN?} \  --set "databases[0].name=example-postgres" \  --set "databases[0].uri=postgres.example.com:5432" \  --set "databases[0].protocol=postgres" \  --set "labels.env=dev" \  --version 15.2.2

kubectl -n teleport-agent get pods
NAME                    READY   STATUS    RESTARTS   AGEteleport-kube-agent-0   1/1     Running   0          32s

Step 5/5. 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
---------------- ------------------ --------
example-postgres Example PostgreSQL env=dev

tsh login --proxy=mytenant.teleport.sh --user=alice
tsh db ls
Name             Description        Labels
---------------- ------------------ --------
example-postgres Example PostgreSQL env=dev

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

To retrieve credentials for a database and connect to it:

tsh db connect --db-user=postgres --db-name=postgres example-postgres

To log out of the database and remove credentials:

Remove credentials for a particular database instance.
tsh db logout example-postgres
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

• Set up automatic database user provisioning.

• 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.