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TCP Application Access

Teleport can provide access to any TCP-based application. This allows users to connect to applications which Teleport doesn't natively support such as SMTP servers or databases not yet natively supported by the Teleport Database Service.

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.

  • 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.
  • TCP application to connect to. In this guide we'll use a PostgreSQL running in Docker as an example. You can also use any TCP-based application you may already have.
  • Host where you will run the Teleport Application Service.

We will assume your Teleport cluster is accessible at teleport.example.com and *.teleport.example.com. You can substitute the address of your Teleport Proxy Service. (For Teleport Cloud customers, this will be similar to mytenant.teleport.sh.)

Application Access and DNS

Teleport assigns a subdomain to each application you configure for Application Access. For example, if you enroll Grafana as a resource, Teleport assigns the resource to the grafana.teleport.example.com subdomain.

If you host the Teleport cluster on your own network, you should update your DNS configuration to account for application subdomains. You can update DNS in one of two ways:

  • Create a single DNS address (A) or canonical name (CNAME) record using wildcard substitution for the subdomain name. For example, create a DNS record with the name *.teleport.example.com.
  • Create a separate DNS address (A) or canonical name (CNAME) record for each application subdomain.

Modifying DNS ensures that the certificate authority—for example, Let's Encrypt—can issue a certificate for each subdomain and that clients can verify Teleport hosts regardless of the application they are accessing.

If you use the Teleport cloud platform, no DNS updates are needed because your Teleport cluster automatically provides the subdomains and signed TLS certificates for your applications under your tenant address.

Step 1/4. Start PostgreSQL container​

Skip this step if you already have an application you'd like to connect to.

Start a PostgreSQL server in a Docker container:

$ docker run --name postgres -p 5432:5432 -e POSTGRES_PASSWORD=<pass> -d postgres

Step 2/4. Start Teleport Application Service​

Teleport Application Service requires a valid auth token to join the cluster.

To generate one, run the following command on your Auth Service node:

$ tctl tokens add --type=app

Next, create a Teleport user with the access role that will allow it to connect to cluster applications:

$ tctl users add --roles=access alice

Save the generated token in /tmp/token on the node where Application Service will run.

Now, install Teleport on the Application Service node. It must be able to reach both your Teleport Proxy and the TCP application it's going to proxy.

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.

Create the Application Service configuration file /etc/teleport.yaml with the following contents:

version: v3
teleport:
  auth_token: "/tmp/token"
  proxy_server: teleport.example.com:3080
auth_service:
  enabled: "no"
ssh_service:
  enabled: "no"
proxy_service:
  enabled: "no"
app_service:
  enabled: "yes"
  apps:
  - name: "tcp-app"
    uri: tcp://localhost:5432

Note that the URI scheme must be tcp:// in order for Teleport to recognize this as a TCP application.

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

On the host where you will run your Teleport instance, enable and start Teleport:

$ sudo systemctl enable teleport
$ sudo systemctl start teleport

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

Step 3/4. Start app proxy​

Log into your Teleport cluster and view available applications:

$ tsh login --proxy=teleport.example.com
$ tsh apps ls
Application Description   Type Public Address                   Labels
----------- ------------- ---- -------------------------------- -----------
tcp-app                   TCP  tcp-app.root.gravitational.io

Your TCP application should show up and be denoted with a TCP type.

Now log into the application:

$ tsh apps login tcp-app
Logged into TCP app tcp-app. Start the local TCP proxy for it:

  tsh proxy app tcp-app

Then connect to the application through this proxy.

Next, start a local proxy for it:

$ tsh proxy app tcp-app
Proxying connections to tcp-app on 127.0.0.1:55868

The tsh proxy app command will set up a listener that will proxy all connections to the target application.

Step 4/4. Connect​

Once the local proxy is running, you can connect to the application using the application client you would normally use to connect to it:

$ psql postgres://postgres@localhost:55868/postgres

Next steps​