Enroll a Kubernetes Cluster

This guide demonstrates how to enroll a Kubernetes cluster as a Teleport resource by deploying the Teleport Kubernetes Service on the Kubernetes cluster you want to protect.

In this scenario, the Teleport Kubernetes Service pod detects that it is running on Kubernetes and enrolls the Kubernetes cluster automatically. The following diagram provides a simplified overview of this deployment scenario with the Teleport Kubernetes Service running on the Kubernetes cluster:

For information about other ways to enroll and discover Kubernetes clusters, see Registering Kubernetes Clusters with Teleport.

Prerequisites

• Access to a running Teleport cluster, tctl admin tool, and tsh client tool, version >= 15.4.22.

  For Teleport Enterprise and Teleport Enterprise Cloud, you should use the Enterprise version of tctl. You can verify the tools you have installed by running the following commands:

  $ tctl version
  # Teleport Enterprise v15.4.22 go1.21
  
  $ tsh version
  # Teleport v15.4.22 go1.21

  You can download these tools by following the appropriate Installation instructions for your environment.

• Kubernetes >= v1.17.0

• Helm >= 3.4.2

  Verify that Helm and Kubernetes are installed and up to date.

  $ helm version
  # version.BuildInfo{Version:"v3.4.2"}
  
  $ kubectl version
  # Client Version: version.Info{Major:"1", Minor:"17+"}
  # Server Version: version.Info{Major:"1", Minor:"17+"}

• 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 1/3. Create RBAC resources

To authenticate to a Kubernetes cluster using Teleport, you must have a Teleport role that grants access to the Kubernetes cluster you plan to interact with.

In this step, we show you how to create a Teleport role called kube-access that enables a user to send requests to any Teleport-protected Kubernetes cluster as a member of the viewers group. The Teleport Kubernetes Service impersonates the viewers group when proxying requests from the user.

1. Create a file called kube-access.yaml with the following content:

   kind: role
   metadata:
     name: kube-access
   version: v7
   spec:
     allow:
       kubernetes_labels:
         '*': '*'
       kubernetes_resources:
         - kind: '*'
           namespace: '*'
           name: '*'
           verbs: ['*']
       kubernetes_groups:
       - viewers
     deny: {}

2. Apply your changes:

   $ tctl create -f kube-access.yaml

3. Assign the kube-access role to your Teleport user by running the appropriate commands for your authentication provider:

   Local User

   1. Retrieve your local user's roles as a comma-separated list:

      $ ROLES=$(tsh status -f json | jq -r '.active.roles | join(",")')

   2. Edit your local user to add the new role:

      $ tctl users update $(tsh status -f json | jq -r '.active.username') \
        --set-roles "${ROLES?},kube-access"

   3. Sign out of the Teleport cluster and sign in again to assume the new role.

   GitHub

   1. Retrieve your github authentication connector:

      $ tctl get github/github --with-secrets > github.yaml

      Note that the --with-secrets flag adds the value of spec.signing_key_pair.private_key to the github.yaml file. Because this key contains a sensitive value, you should remove the github.yaml file immediately after updating the resource.

   2. Edit github.yaml, adding kube-access to the teams_to_roles section.

      The team you should map to this role depends on how you have designed your organization's role-based access controls (RBAC). However, the team must include your user account and should be the smallest team possible within your organization.

      Here is an example:

        teams_to_roles:
          - organization: octocats
            team: admins
            roles:
              - access
      +       - kube-access

   3. Apply your changes:

      $ tctl create -f github.yaml

   4. Sign out of the Teleport cluster and sign in again to assume the new role.

   SAML

   1. Retrieve your saml configuration resource:

      $ tctl get --with-secrets saml/mysaml > saml.yaml

      Note that the --with-secrets flag adds the value of spec.signing_key_pair.private_key to the saml.yaml file. Because this key contains a sensitive value, you should remove the saml.yaml file immediately after updating the resource.

   2. Edit saml.yaml, adding kube-access to the attributes_to_roles section.

      The attribute you should map to this role depends on how you have designed your organization's role-based access controls (RBAC). However, the group must include your user account and should be the smallest group possible within your organization.

      Here is an example:

        attributes_to_roles:
          - name: "groups"
            value: "my-group"
            roles:
              - access
      +       - kube-access

   3. Apply your changes:

      $ tctl create -f saml.yaml

   4. Sign out of the Teleport cluster and sign in again to assume the new role.

   OIDC

   1. Retrieve your oidc configuration resource:

      $ tctl get oidc/myoidc --with-secrets > oidc.yaml

      Note that the --with-secrets flag adds the value of spec.signing_key_pair.private_key to the oidc.yaml file. Because this key contains a sensitive value, you should remove the oidc.yaml file immediately after updating the resource.

   2. Edit oidc.yaml, adding kube-access to the claims_to_roles section.

      The claim you should map to this role depends on how you have designed your organization's role-based access controls (RBAC). However, the group must include your user account and should be the smallest group possible within your organization.

      Here is an example:

        claims_to_roles:
          - name: "groups"
            value: "my-group"
            roles:
              - access
      +       - kube-access

   3. Apply your changes:

      $ tctl create -f oidc.yaml

   4. Sign out of the Teleport cluster and sign in again to assume the new role.

While you have authorized the kube-access role to access Kubernetes clusters as a member of the viewers group, this group does not yet have permissions within its Kubernetes cluster. To assign these permissions, create a Kubernetes RoleBinding or ClusterRoleBindings that grants permission to the viewers group.

1. Create a file called viewers-bind.yaml with the following contents:

   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRoleBinding
   metadata:
     name: viewers-crb
   subjects:
   - kind: Group
     # Bind the group "viewers" to the kubernetes_groups assigned in the "kube-access" role
     name: viewers
     apiGroup: rbac.authorization.k8s.io
   roleRef:
     kind: ClusterRole
     # "view" is a default ClusterRole that grants read-only access to resources
     # See: https://kubernetes.io/docs/reference/access-authn-authz/rbac/#user-facing-roles
     name: view
     apiGroup: rbac.authorization.k8s.io

2. Apply the ClusterRoleBinding with kubectl:

   $ kubectl apply -f viewers-bind.yaml

Your Teleport user now has permissions to assume membership in the viewers group when accessing your Kubernetes cluster, and the viewers group now has permissions to view resources in the cluster. The next step is to deploy the Teleport Kubernetes Service in the cluster to proxy user requests.

Step 2/3. Follow guided enrollment instructions

In this step, you will deploy the Teleport Kubernetes Service on your Kubernetes cluster by copying a script from the Teleport Web UI and running it on your terminal.

1. Open the Teleport Web UI and sign in using your administrative account.

2. Click Enroll New Resource.

3. Type all or part of Kubernetes in the Search field to filter the resource types displayed, then click Kubernetes.

4. Copy the command to add the teleport-agent chart repository and paste it in a terminal on your workstation.

5. Type teleport-agent for namespace where you will deploy the Teleport Kubernetes Service and the display name to use when connecting to this cluster, then click Next.

   After you click Next, Teleport generates a script to configure and enroll the Kubernetes cluster as a resource in the Teleport cluster.

6. Copy the command displayed in the Teleport Web UI and run it in your terminal.

   The Teleport Web UI displays "Successfully detected your new Kubernetes cluster" as confirmation that your cluster is enrolled. When you see this message, click Next to continue.

Step 3/3. Test Kubernetes access

Now that you have deployed the Teleport Kubernetes Service on your Kubernetes cluster and enrolled the cluster as a Teleport resource, confirm that you can access your Kubernetes cluster as a member of the viewers group.

If you followed the previous steps in this guide, the Set Up Access view populates the Kubernetes Groups field with viewers.

To set up and test access:

1. Click Next.

2. Specify the teleport-agent namespace, the Kubernetes viewers group from the previous step, and your Teleport user name.

3. Copy and run the commands displayed in the Teleport Web UI to interact with the Kubernetes cluster and verify access through Teleport. Alternatively, run the commands shown below:

   Authenticate to your Teleport cluster:

   $ tsh login --proxy=teleport.example.com:443 --auth=local --user=admin@example.com teleport.example.com

   List Kubernetes clusters available for you to access:

   $ tsh kube ls

   Retrieve credentials to access your Kubernetes cluster:

   $ tsh kube login Kubernetes-cluster-name

   The Teleport Kubernetes Service proxies kubectl commands:

   $ kubectl get pods -n teleport-agent

   You should see the Teleport Kubernetes Service pod you deployed earlier:

   NAME               READY   STATUS    RESTARTS   AGE
   teleport-agent-0   1/1     Running   0          8m6s

4. Click Finish.

Next steps

This guide demonstrated how to enroll a Kubernetes cluster by running the Teleport Kubernetes Service within the Kubernetes cluster.

• For information about discovering Kubernetes clusters hosted on cloud providers, see Kubernetes Cluster Discovery.
• To learn about other ways you can register a Kubernetes cluster with Teleport, see Registering Kubernetes Clusters with Teleport.
• For a complete list of the parameters you can configure in the teleport-kube-agent helm chart, see the Chart Reference.