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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.

Prerequisites

  • A running Teleport cluster version 16.0.0 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.

    Visit Installation for instructions on downloading tctl and tsh.

  • 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 protected]
    tctl status

    Cluster teleport.example.com

    Version 16.0.0

    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

Create a Teleport user

Tip

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

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

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

Create a local Teleport user with the built-in access and requester roles:

tctl users add \ --roles=access,requester \ --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.

If the PostgreSQL database already has a CA that it uses to sign certificates , you only need to export a Teleport CA certificate for the database to authenticate traffic from the Teleport Database Service. You do not need to enable Db impersonation privileges.

  1. Replace example.teleport.sh:443 with the host and web port of the Teleport Proxy Service in your cluster. Run the following command on your workstation:

    tctl auth export --type=db-client --auth-server=example.teleport.sh:443 > db-client.cas

    The command creates 1 file, db-client.cas.

  2. Append the contents of db-client.cas to your database's existing CA cert file, which this guide expects to be called server.cas.

  3. Generate server.crt and server.key by retrieving a TLS certificate and private key from your existing database CA, signed for your database server. You will use these files later in the guide.

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'

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://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.

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

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

On the host where you will run the Teleport Database Service, create a systemd service configuration for Teleport, enable the Teleport service, and 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.

Teleport provides Helm charts for installing the Teleport Database Service in Kubernetes Clusters.

Set up the Teleport Helm repository.

Allow Helm to install charts that are hosted in the Teleport Helm repository:

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

Update the cache of charts from the remote repository so you can upgrade to all available releases:

helm repo update

Install a Teleport agent into your Kubernetes Cluster with the Teleport Database Service configuration.

Create a file called values.yaml with the following content. Update example.teleport.sh to use the host and port of the Teleport Proxy Service and JOIN_TOKEN to the join token you created earlier:

roles: db
proxyAddr: example.teleport.sh
# Set to false if using Teleport Community Edition
enterprise: true
authToken: "JOIN_TOKEN"
databases:
  - name: example-postgres
    uri: postgres.example.com:5432
    protocol: postgres
    static_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 db.ca on your workstation.

  2. Create a secret containing the database CA certificate in the same namespace as Teleport using the following command:

    kubectl create secret generic db-ca --from-file=ca.pem=/path/to/db.ca
  3. Add the following to values.yaml:

      roles: db
      proxyAddr: varc188368e0d32437cb9ea3670cbd464f9
      # Set to false if using Teleport Community Edition
      enterprise: true
      authToken: vardae08f17ad5243a599c722faa2a0e42f
      databases:
        - name: example-postgres
          uri: postgres.example.com:5432
          protocol: postgres
    +     tls:
    +       ca_cert_file: "/etc/teleport-tls-db/db-ca/ca.pem"
          static_labels:
            env: dev
    + extraVolumes:
    +   - name: db-ca
    +     secret:
    +       secretName: db-ca
    + extraVolumeMounts:
    +   - name: db-ca
    +     mountPath: /etc/teleport-tls-db/db-ca
    +     readOnly: true
    
  4. Install the chart:

    helm install teleport-kube-agent teleport/teleport-kube-agent \ --create-namespace \ --namespace teleport-agent \ --version 16.0.0 \ -f values.yaml
  5. Make sure that the Teleport agent pod is running. You should see one teleport-kube-agent pod with a single ready container:

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

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

  • Take a look at the YAML configuration reference.