Join Services with GCP

This guide will explain how to use the GCP join method to configure Teleport processes to join your Teleport cluster without sharing any secrets when they are running in a GCP VM.

The GCP join method is available to any Teleport process running on a GCP VM. The VM must have a service account assigned to it (the default service account is fine). No IAM roles are required on the Teleport process joining the cluster.

Prerequisites

• A running Teleport cluster version 17.0.2 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 GCP VM to host a Teleport service, with a service account assigned to it and with the Teleport binary installed.
• 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. For example:

  tsh login --proxy=teleport.example.com --user=email@example.com
  tctl status
  Cluster  teleport.example.com
  Version  17.0.2
  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 1/3. Create the GCP joining token

Configure your Teleport Auth Service with a special dynamic token which will allow services from your GCP projects to join your Teleport cluster.

Under the hood, services will prove that they are running in your GCP project by sending a signed ID token which matches an allow rule configured in your GCP joining token.

Create the following token.yaml file with a gcp.allow rule specifying your GCP project ID(s), service account(s), and location(s) in which your GCP instances will run:

# token.yaml
kind: token
version: v2
metadata:
  # the token name is not a secret because instances must prove that they are
  # running in your GCP project to use this token
  name: gcp-token
spec:
  # use the minimal set of roles required (e.g. Node, Proxy, App, Kube, DB, WindowsDesktop)
  roles: [Node]

  # set the join method allowed for this token
  join_method: gcp

  gcp:
    allow:
      # The GCP project ID(s) that VMs can join from.
      - project_ids: ["example-project-id"]
        # (Optional) The locations that VMs can join from. Note: both regions and
        # zones are accepted.
        locations: ["us-west1", "us-west2-a"]
        # (Optional) The email addresses of service accounts that VMs can join
        # with.
        service_accounts: ["example@example.com"]

Run the following command to create the token:

tctl create token.yaml

Step 2/3. Configure your services

The GCP join method can be used for Teleport processes running the SSH (Node), Proxy, Kubernetes, Application, Database, or Windows Desktop Services. The Teleport process should be run directly on a GCP VM.

Configure your Teleport process with a custom teleport.yaml file. Use the join_params section with token_name matching your token created in Step 1 and method: gcp as shown in the following example config:

# /etc/teleport.yaml
version: v3
teleport:
  join_params:
    token_name: gcp-token
    method: gcp
  proxy_server: https://teleport.example.com:443
ssh_service:
  enabled: yes
auth_service:
  enabled: no
proxy_service:
  enabled: no

Step 3/3. Launch your Teleport process

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.

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 your Teleport instance with systemctl status teleport and view its logs with journalctl -fu teleport.

Once you have started Teleport, confirm that your service is able to connect to and join your cluster.