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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 the Teleport RBAC system.

The Teleport Database Service proxies traffic from database clients to self-hosted databases in your infrastructure. Teleport maintains a certificate authority for database clients. You configure your database to trust the Teleport database client CA, and the Teleport Database Service presents certificates signed by this CA when proxying user traffic. With this setup, there is no need to store long-lived credentials for self-hosted databases.

Meanwhile, the Teleport Database Service verifies self-hosted databases by checking their TLS certificates against either the Teleport database CA or a custom CA chosen by the user.

In this guide, you will:

  1. Configure your PostgreSQL database for Teleport access.
  2. Add the database to your Teleport cluster.
  3. Connect to the database via Teleport.

How it works​

The Teleport Database Service authenticates to your self-hosted PostgreSQL database using mutual TLS. PostgreSQL trusts the Teleport certificate authority for database clients, and presents a certificate signed by either the Teleport database CA or a custom CA. When a user initiates a database session, the Teleport Database Service presents a certificate signed by Teleport. The authenticated connection then proxies client traffic from the user.

Teleport Database Access PostgreSQL Self-Hosted

Prerequisites​

  • A running Teleport cluster version 15.4.22 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.

  • 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.
  • Optional: a certificate authority that issues certificates for your self-hosted database.
  • 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  15.4.22
    # 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 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
abcd123-insecure-do-not-use-this

Create a Teleport user​

tip

To modify an existing user to provide access to the Database Service, see Database Access Controls

Create a local Teleport user with the built-in access role:

$ tctl users add \
  --roles=access \
  --db-users="*" \
  --db-names="*" \
  alice
FlagDescription
--rolesList of roles to assign to the user. The builtin access role allows them to connect to any database server registered with Teleport.
--db-usersList of database usernames the user will be allowed to use when connecting to the databases. A wildcard allows any user.
--db-namesList of logical databases (aka schemas) the user will be allowed to connect to within a database server. A wildcard allows any database.
warning

Database names are only enforced for PostgreSQL, MongoDB, and Cloud Spanner databases.

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 able to verify certificates presented by the Teleport Database Service. Self-hosted databases also need a certificate/key pair that Teleport can verify.

By default, the Teleport Database Service trusts certificates issued by a certificate authority managed by the Teleport Auth Service. You can either:

  • Configure your self-hosted database to trust this CA, and instruct Teleport to issue a certificate for the database to present to the Teleport Database Service.
  • Configure the Database Service to trust a custom CA.

To configure the database to trust the Teleport CA and issue a certificate for the database, follow these instructions on your workstation:

  1. To use tctl from your workstation, 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 user's role:

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

  2. Export Teleport's certificate authority and a generate certificate/key pair. This example generates a certificate with a 1-year validity period. db.example.com is the hostname where the Teleport Database Service can reach the PostgreSQL server.

    $ tctl auth sign --format=db --host=db.example.com --out=server --ttl=2190h
    TTL

    We recommend using a shorter TTL, but keep mind that you'll need to update the database server certificate before it expires to not lose the ability to connect. Pick the TTL value that best fits your use-case.

    The command creates 3 files: server.cas, server.crt and server.key.

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, using the paths where you placed the server.crt, server.key, and server.cas files you generated earlier:

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

Restart the PostgreSQL instance to enable this configuration.

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

Configure PostgreSQL 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 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:

Install Teleport on your Linux server:

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

    EditionValue
    Teleport Enterprise Cloudcloud
    Teleport Enterprise (Self-Hosted)enterprise
    Teleport Community Editionoss

  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://cdn.teleport.dev/install-v15.4.22.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.

On the host where you will run the Teleport Database Service, start Teleport with the appropriate configuration.

Note that a single Teleport process can run multiple different services, for example multiple Database Service agents as well as the SSH Service or Application Service. The step below will overwrite an existing configuration file, so if you're running multiple services add --output=stdout to print the config in your terminal, and manually adjust /etc/teleport.yaml.

Run the following command to generate a configuration file at /etc/teleport.yaml for the Database Service. Update example.teleport.sh to use the host and port of the Teleport Proxy Service:

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

To configure the Teleport Database Service to trust a custom CA:

  1. Export a CA certificate for the custom CA and make it available at /var/lib/teleport/db.ca on the Teleport Database Service host.

  2. Run a variation of the command above that uses the --ca-cert-file flag. This configures the Teleport Database Service to use the CA certificate at db.ca to verify traffic from the database:

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

If your database servers use certificates that are signed by a public CA such as ComodoCA or DigiCert, you can use the trust_system_cert_pool option without exporting the CA:

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

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.

On the host where you will run the Teleport Database Service, enable and start Teleport:

$ 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.

Tip

A single Teleport process can run multiple services, for example multiple Database Service instances as well as other services such the SSH Service or Application Service.

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

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​

  • Take a look at the YAML configuration reference.