Dynamic Kubernetes Cluster Registration

With dynamic Kubernetes cluster registration, you can manage the Kubernetes clusters connected to your Teleport cluster without needing to modify the configuration file of an individual Kubernetes Service instance.

Dynamic Kubernetes cluster registration is useful when you have deployed multiple Kubernetes Service instances or need to regularly reconfigure access to Kubernetes clusters in your infrastructure.

In this guide, we will show you how to set up dynamic Kubernetes cluster registration, then create, list, update, and delete Kubernetes clusters via tctl.

Prerequisites

tctl version
Teleport v14.2.0 git:api/14.0.0-gd1e081e go1.21
  
tsh version
Teleport v14.2.0 go1.21
Proxy version: 14.2.0Proxy: teleport.example.com

tctl version
Teleport Enterprise v14.1.3 git:api/14.0.0-gd1e081e go1.21
  
tsh version
Teleport v14.1.3 go1.21
Proxy version: 14.1.3Proxy: teleport.example.com

tctl version
Teleport Enterprise v14.2.0 git:api/14.0.0-gd1e081e go1.21
  
tsh version
Teleport v14.2.0 go1.21
Proxy version: 14.2.0Proxy: teleport.example.com

tctl version
Teleport Enterprise v14.1.3 git:api/14.0.0-gd1e081e go1.21
  
tsh version
Teleport v14.1.3 go1.21
Proxy version: 14.1.3Proxy: teleport.example.com

• A Linux host where you will install the Teleport Kubernetes Service.

  Our teleport-kube-agent Helm chart does not support dynamic Kubernetes cluster registration.

• A Kubernetes cluster to join to your Teleport cluster. You must have permissions to create namespaces, secrets, service accounts, cluster roles, and cluster role bindings in the cluster.

• 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  14.2.0
  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 1/3. Set up the Teleport Kubernetes Service

The Teleport Kubernetes Service proxies traffic from Teleport users to a Kubernetes API server so you can take advantage of passwordless authentication, role-based access controls, audit logging, and other Teleport features in order to manage access to Kubernetes.

In this step, you will install the Teleport Kubernetes Service on a Linux host and configure it to access any Kubernetes cluster you register with your Teleport cluster.

Get a join token

Establish trust between your Teleport cluster and your new Kubernetes Service instance by creating a join token:

tctl tokens add --type=kube --ttl=1h --format=text
abcd123-insecure-do-not-use-this

Copy the token and keep it somewhere safe so you can use it when running the Teleport Kubernetes Service.

Install the Teleport Kubernetes Service

Install the Teleport Kubernetes Service on your Linux host:

Select an edition, then follow the instructions for that edition to install Teleport.

curl https://goteleport.com/static/install.sh | bash -s 14.2.0

Download Teleport's PGP public key
sudo curl https://apt.releases.teleport.dev/gpg \-o /usr/share/keyrings/teleport-archive-keyring.asc
Source variables about OS version
source /etc/os-release
Add the Teleport APT repository for cloud.
echo "deb [signed-by=/usr/share/keyrings/teleport-archive-keyring.asc] \https://apt.releases.teleport.dev/${ID?} ${VERSION_CODENAME?} stable/cloud" \| sudo tee /etc/apt/sources.list.d/teleport.list > /dev/null

sudo apt-get update
sudo apt-get install teleport-ent-updater

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
sudo yum-config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-yum.repo")"
sudo yum install teleport-ent-updater
Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use the dnf config manager plugin to add the teleport RPM repo
sudo dnf config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-yum.repo")"

Install teleport
sudo dnf install teleport-ent-updater

Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

Source variables about OS version
source /etc/os-release
Add the Teleport Zypper repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use Zypper to add the teleport RPM repo
sudo zypper addrepo --refresh --repo $(rpm --eval "https://zypper.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-zypper.repo")

Install teleport
sudo zypper install teleport-ent-updater

Download Teleport's PGP public key
sudo curl https://apt.releases.teleport.dev/gpg \-o /usr/share/keyrings/teleport-archive-keyring.asc
Source variables about OS version
source /etc/os-release
Add the Teleport APT repository for v14. You'll need to update this
file for each major release of Teleport.
echo "deb [signed-by=/usr/share/keyrings/teleport-archive-keyring.asc] \https://apt.releases.teleport.dev/${ID?} ${VERSION_CODENAME?} stable/v14" \| sudo tee /etc/apt/sources.list.d/teleport.list > /dev/null

sudo apt-get update
sudo apt-get install teleport-ent

sudo apt-get install teleport-ent-fips

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for v14. You'll need to update this
file for each major release of Teleport.
First, get the major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
sudo yum-config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/v14/teleport.repo")"
sudo yum install teleport-ent
Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

sudo yum install teleport-ent-fips

Source variables about OS version
source /etc/os-release
Add the Teleport Zypper repository for v14. You'll need to update this
file for each major release of Teleport.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use zypper to add the teleport RPM repo
sudo zypper addrepo --refresh --repo $(rpm --eval "https://zypper.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-zypper.repo")
sudo yum install teleport-ent
Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

sudo yum install teleport-ent-fips

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for v14. You'll need to update this
file for each major release of Teleport.
First, get the major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use the dnf config manager plugin to add the teleport RPM repo
sudo dnf config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/v14/teleport.repo")"

Install teleport
sudo dnf install teleport-ent

Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

sudo dnf install teleport-ent-fips

Source variables about OS version
source /etc/os-release
Add the Teleport Zypper repository.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use Zypper to add the teleport RPM repo
sudo zypper addrepo --refresh --repo $(rpm --eval "https://zypper.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/v14/teleport-zypper.repo")

Install teleport
sudo zypper install teleport-ent

sudo zypper install teleport-ent-fips

curl https://get.gravitational.com/teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-bin.tar.gz.sha256
<checksum> <filename>
curl -O https://cdn.teleport.dev/teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-bin.tar.gz
shasum -a 256 teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-bin.tar.gz
Verify that the checksums match
tar -xvf teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-bin.tar.gz
cd teleport-ent
sudo ./install

curl https://get.gravitational.com/teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-fips-bin.tar.gz.sha256
<checksum> <filename>
curl -O https://cdn.teleport.dev/teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-fips-bin.tar.gz
shasum -a 256 teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-fips-bin.tar.gz
Verify that the checksums match
tar -xvf teleport-ent-v14.2.0-linux-$SYSTEM_ARCH-fips-bin.tar.gz
cd teleport-ent
sudo ./install

Download Teleport's PGP public key
sudo curl https://apt.releases.teleport.dev/gpg \-o /usr/share/keyrings/teleport-archive-keyring.asc
Source variables about OS version
source /etc/os-release
Add the Teleport APT repository for cloud.
echo "deb [signed-by=/usr/share/keyrings/teleport-archive-keyring.asc] \https://apt.releases.teleport.dev/${ID?} ${VERSION_CODENAME?} stable/cloud" \| sudo tee /etc/apt/sources.list.d/teleport.list > /dev/null

sudo apt-get update
sudo apt-get install teleport-ent-updater

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
sudo yum-config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-yum.repo")"
sudo yum install teleport-ent-updater
Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

Source variables about OS version
source /etc/os-release
Add the Teleport YUM repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use the dnf config manager plugin to add the teleport RPM repo
sudo dnf config-manager --add-repo "$(rpm --eval "https://yum.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-yum.repo")"

Install teleport
sudo dnf install teleport-ent-updater

Tip: Add /usr/local/bin to path used by sudo (so 'sudo tctl users add' will work as per the docs)
echo "Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin" > /etc/sudoers.d/secure_path

Source variables about OS version
source /etc/os-release
Add the Teleport Zypper repository for cloud.
First, get the OS major version from $VERSION_ID so this fetches the correct
package version.
VERSION_ID=$(echo $VERSION_ID | grep -Eo "^[0-9]+")
Use Zypper to add the teleport RPM repo
sudo zypper addrepo --refresh --repo $(rpm --eval "https://zypper.releases.teleport.dev/$ID/$VERSION_ID/Teleport/%{_arch}/stable/cloud/teleport-zypper.repo")

Install teleport
sudo zypper install teleport-ent-updater

Configure the Teleport Kubernetes Service

On the host where you will run the Teleport Kubernetes Service, run the following command to create a base configuration for your Teleport instance, assigning PROXY_SERVICE to the host and port of your Teleport Proxy Service or Teleport Cloud tenant and TOKEN to the join token we created earlier:

e.g., teleport.example.com:443
PROXY_SERVICE=proxy-addr
e.g., abcd123-insecure-do-not-use-this;
TOKEN=join-token;
sudo teleport configure \--proxy=${PROXY_SERVICE?} \--roles=kube \--token=${TOKEN?} \-o file

Edit your configuration file at /etc/teleport.yaml to include the following:

kubernetes_service:
  enabled: "yes"
  resources:
  - labels:
      "*": "*"

This configuration enables your Kubernetes Service instance to connect to any Kubernetes clusters you register with your Teleport cluster. This is because the resources[0].labels field includes the wildcard pattern ("*": "*"), which allows this Kubernetes Service instance to connect to Kubernetes cluster resources with any label key or value.

resources:
- labels:
    "env": "prod"
    "region": "us-east-2"
- labels:
    "env": "test"
    "region": "us-west-1"

Run the Teleport Kubernetes Service

Configure the Teleport Kubernetes 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 Kubernetes Service.

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 the Teleport Kubernetes Service with systemctl status teleport and view its logs with journalctl -fu teleport.

Step 2/3. Authorize your user

To enable dynamic Kubernetes cluster registration in Teleport, you will need to authorize your user to access the Kubernetes clusters you want to register with Teleport. We will configure this access in this step, both in Teleport and on your Kubernetes cluster.

Allow access to your Kubernetes cluster

Ensure that you are in the correct Kubernetes context for the cluster you would like to enable access to.

Retrieve all available contexts:

kubectl config get-contexts

Switch to your context, replacing CONTEXT_NAME with the name of your chosen context:

kubectl config use-context CONTEXT_NAME
Switched to context CONTEXT_NAME

Kubernetes authentication

To authenticate to a Kubernetes cluster via Teleport, your Teleport roles must allow access as at least one Kubernetes user or group. Ensure that you have a Teleport role that grants access to the cluster you plan to interact with.

Run the following command to get the Kubernetes user for your current context:

kubectl config view \-o jsonpath="{.contexts[?(@.name==\"$(kubectl config current-context)\")].context.user}"

Create a file called kube-access.yaml with the following content, replacing USER with the output of the command above.

kind: role
metadata:
  name: kube-access
version: v7
spec:
  allow:
    kubernetes_labels:
      '*': '*'
    kubernetes_resources:
      - kind: '*'
        namespace: '*'
        name: '*'
        verbs: ['*']
    kubernetes_groups:
    - viewers
    kubernetes_users:
    # Replace USER with the Kubernetes user for your current context.
    - USER
  deny: {}

Apply your changes:

tctl create -f kube-access.yaml

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

Now that Teleport RBAC is configured, you can authenticate to your Kubernetes cluster via Teleport. To interact with your Kubernetes cluster, you will need to configure authorization within Kubernetes.

Kubernetes authorization

To configure authorization within your Kubernetes cluster, you need to create Kubernetes RoleBindings or ClusterRoleBindings that grant permissions to the subjects listed in kubernetes_users and kubernetes_groups.

For example, you can grant some limited read-only permissions to the viewers group used in the kube-access role defined above:

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", corresponding to the kubernetes_groups we assigned our "kube-access" role above
  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

Apply the ClusterRoleBinding with kubectl:

kubectl apply -f viewers-bind.yaml

Log out of Teleport and log in again.

Authorize your user to manage Kubernetes clusters

Teleport tracks Kubernetes clusters in your infrastructure via dynamic kube_cluster resources. To manage access to Kubernetes clusters with Teleport, your user will need permissions to manage these resources.

In the previous section, you authorized your user to access all Kubernetes clusters registered in your Teleport cluster. Now that you can access these clusters, create a role that enables you to manage them.

Create a role definition called kube-manager.yaml with the following content:

kind: role
metadata:
  name: kube-manager
spec:
  allow:
    rules:
    - resources:
      - kube_cluster
      verbs:
      - list
      - create
      - read
      - update
      - delete
version: v5

Create the role:

tctl create -f kube-manager.yaml

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

Step 3/3. Manage dynamic Kubernetes cluster resources

Now that your Teleport user has permissions to manage Kubernetes cluster resources, we will show you how to create, list, update, and delete them.

Create a kubeconfig

In this section, you will create a Kubernetes Config resource, or kubeconfig, that your Teleport cluster will use to authenticate to your Kubernetes cluster.

When you signed into Teleport earlier in this guide, tsh may have changed your Kubernetes context to one based on your Teleport cluster, so make sure you update your Kubernetes context to match the cluster you would like to connect to Teleport:

kubectl config get-contexts
Assign CONTEXT_NAME to your chosen context
kubectl config use-context CONTEXT_NAME

On your workstation, download Teleport's get-kubeconfig.sh script, which you will use to generate the kubeconfig:

curl -OL \https://raw.githubusercontent.com/gravitational/teleport/v14.2.0/examples/k8s-auth/get-kubeconfig.sh

The script creates a service account for the Teleport Kubernetes Service that can get Kubernetes pods as well as impersonate users, groups, and other service accounts. The Teleport Kubernetes Service uses this service account to manage access to resources in your Kubernetes cluster. The script also ensures that there is a Kubernetes Secret in your cluster to store service account credentials.

get-kubeconfig.sh creates a namespace called teleport for the resources it deploys, though you can choose a different name by assigning the TELEPORT_NAMESPACE environment variable in the shell where you run the script.

After creating resources, get-kubeconfig.sh writes a new kubeconfig to a file called kubeconfig in the directory where you run the script.

Run the get-kubeconfig.sh script:

bash get-kubeconfig.sh

The script is successful if you see this message:

Done!

Ignore the script's instructions to copy the generated kubeconfig file to the Teleport Proxy Service. In the next section, we will show you how to use the kubeconfig file when creating a dynamic kube_cluster resource.

Create a Kubernetes cluster resource

Define a kube_cluster resource with the following content in a file called kube_cluster.yaml:

kind: kube_cluster
version: v3
metadata:
  name: mycluster
spec:
  kubeconfig: |

The spec.kubeconfig field in the snippet above begins a multi-line string. Below, you will include the contents of the kubeconfig file as its value.

Since spec.kubeconfig must be a base64-encoded string, convert the kubeconfig file to base64, then indent it and add it to the kube_cluster.yaml resource definition using the following command:

printf "    %s" $(cat kubeconfig | base64) >> kube_cluster.yaml

kind: kube_cluster
version: v3
metadata:
  name: mycluster
  labels:
    env: prod
    team: dev
spec:
  kubeconfig: KUBECONFIG

kind: kube_cluster
version: v3
metadata:
  name: mycluster
spec:
  kubeconfig: KUBECONFIG
  dynamic_labels:
    region:
      period: "24h"
      command: ["python3", "get_region.py"]

To create the kube_cluster resource, run the following command:

tctl create kube_cluster.yaml
kubernetes cluster "mycluster" has been created

Access your new Kubernetes cluster

Instances of the Teleport Kubernetes Service watch for newly created or updated kube_cluster resources. When you create the kube_cluster resource, any Kubernetes Service instances you have configured to track that cluster's labels will register that cluster and enable access to it via Teleport.

As a result, you should now see the cluster you registered above when you run tsh kube ls:

tsh kube ls
 Kube Cluster Name Labels                      Selected ----------------- --------------------------- -------- mycluster         teleport.dev/origin=dynamic

The teleport.dev/origin=dynamic label indicates that the cluster was registered dynamically.

You can also log in to the cluster you just registered:

tsh kube login mycluster
Logged into kubernetes cluster "mycluster". Try 'kubectl version' to test theconnection.

List Kubernetes cluster resources

You can list kube_cluster resources with the following command:

tctl get kube_clusters

Update a Kubernetes cluster resource

To update the kube_cluster resource you created earlier, execute the following command to retrieve the resource as it exists on the Auth Service's backend:

tctl get kube_clusters/mycluster > kube_cluster.yaml

Edit the kube_cluster.yaml file to add a label to your kube_cluster:

  kind: kube_cluster
  metadata:
    id: 9999999999999999999
    labels:
      teleport.dev/origin: dynamic
+     env: test
    name: mycluster
  spec:
    aws: {}
    azure: {}
    kubeconfig: KUBECONFIG
  version: v3

Update the resource:

tctl create -f kube_cluster.yaml
kubernetes cluster "mycluster" has been updated

You should now see the updated labels:

tsh kube ls
 Kube Cluster Name Labels                               Selected ----------------- ------------------------------------ -------- mycluster         env=test teleport.dev/origin=dynamic *

Delete Kubernetes cluster resources

To delete the kube_cluster resource you created earlier, run the following command:

tctl rm kube_clusters/mycluster
kubernetes cluster "mycluster" has been deleted

This will unregister the Kubernetes cluster from Teleport:

tsh kube ls
Kube Cluster Name Labels Selected----------------- ------ --------

Next steps

In this guide, we showed you how to manage kube_cluster resources using tctl. If you are interested in other ways you can manage access to Kubernetes clusters via Teleport, check out the following guides:

• Connect a Kubernetes Cluster to Teleport: How to use the teleport-kube-agent Helm chart to register a Kubernetes cluster with Teleport.
• Kubernetes Access from a Standalone Teleport Cluster: How to use the Teleport Kubernetes Service's configuration file to register a Kubernetes cluster with Teleport.