Teleport
Dynamic Kubernetes Cluster Registration
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- Version 17.x
- Version 16.x
- Version 15.x
- Older Versions
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
-
A running Teleport cluster version 16.4.10 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 andtsh
client tool.Visit Installation for instructions on downloading
tctl
andtsh
.
-
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 runtctl
commands using your current credentials.For example:
tsh login --proxy=teleport.example.com --user=[email protected]tctl statusCluster teleport.example.com
Version 16.4.10
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 subsequenttctl
commands from your workstation. If you host your own Teleport cluster, you can also runtctl
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=textabcd123-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:
Install Teleport on your Linux server:
-
Assign edition to one of the following, depending on your Teleport edition:
Edition Value Teleport Enterprise Cloud cloud
Teleport Enterprise (Self-Hosted) enterprise
Teleport Community Edition oss
-
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.comTELEPORT_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.comTELEPORT_VERSION="$(curl https://$TELEPORT_DOMAIN/v1/webapi/ping | jq -r '.server_version')" -
Install Teleport on your Linux server:
curl https://cdn.teleport.dev/install-v16.4.10.sh | bash -s ${TELEPORT_VERSION} editionThe installation script detects the package manager on your Linux server and uses it to install Teleport binaries. To customize your installation, learn about the Teleport package repositories in the installation guide.
Configure the Teleport Kubernetes Service
On the host where you will run the Teleport Kubernetes Service, run the
following command to create a base configuration for your Teleport instance,
assigning PROXY_SERVICE
to the host and port of your Teleport Proxy Service or
Teleport Cloud tenant and TOKEN
to the join token we created earlier:
e.g., teleport.example.com:443
PROXY_SERVICE=proxy-addre.g., abcd123-insecure-do-not-use-this;
TOKEN=join-token;sudo teleport configure \--proxy=${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.
You can configure a Kubernetes Service instance to watch for a subset of Kubernetes clusters by including specific label keys and values instead of wildcard characters:
resources:
- labels:
"env": "prod"
"region": "us-east-2"
- labels:
"env": "test"
"region": "us-west-1"
For the Kubernetes Service to register a cluster, any of the items in
resources
must match the cluster's labels. For an item in resources
to
match, all of the labels
entries within that item must match the cluster's
labels.
For example, a cluster with the labels env:prod
and region:us-west-1
would
not match the configuration above, since it only matches the env:prod
label in
the first resources
item and the region:us-west-1
label in the second
resources
item.
However, a cluster with env:test
and region:us-west-1
would match, since it
matches both labels given in the second resources
item.
When you create dynamic Kubernetes cluster resources later in this guide, you can assign them labels to ensure that only specific Kubernetes Service instances will watch for them.
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.
On the host where you will run the Teleport Kubernetes Service, enable and start Teleport:
sudo systemctl enable teleportsudo systemctl start teleport
On the host where you will run the Teleport Kubernetes Service, create a systemd service configuration for Teleport, enable the Teleport service, and start Teleport:
sudo teleport install systemd -o /etc/systemd/system/teleport.servicesudo systemctl enable teleportsudo 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_NAMESwitched to context CONTEXT_NAME
To authenticate to a Kubernetes cluster via Teleport, your Teleport user's roles must allow access as at least one Kubernetes user or group.
-
Retrieve a list of your current user's Teleport roles. The example below requires the
jq
utility for parsing JSON:CURRENT_ROLES=$(tsh status -f json | jq -r '.active.roles | join ("\n")') -
Retrieve the Kubernetes groups your roles allow you to access:
echo "$CURRENT_ROLES" | xargs -I{} tctl get roles/{} --format json | \ jq '.[0].spec.allow.kubernetes_groups[]?' -
Retrieve the Kubernetes users your roles allow you to access:
echo "$CURRENT_ROLES" | xargs -I{} tctl get roles/{} --format json | \ jq '.[0].spec.allow.kubernetes_users[]?' -
If the output of one of the previous two commands is non-empty, your user can access at least one Kubernetes user or group, so you can proceed to the next step.
-
If both lists are empty, create a Teleport role for the purpose of this guide that can view Kubernetes resources in your cluster.
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: {}
-
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:-
Retrieve your local user's roles as a comma-separated list:
ROLES=$(tsh status -f json | jq -r '.active.roles | join(",")') -
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" -
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Open your
github
authentication connector in a text editor:tctl edit github/github -
Edit the
github
connector, addingkube-access
to theteams_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
-
Apply your changes by saving closing the file in your editor.
-
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Retrieve your
saml
configuration resource:tctl get --with-secrets saml/mysaml > saml.yamlNote that the
--with-secrets
flag adds the value ofspec.signing_key_pair.private_key
to thesaml.yaml
file. Because this key contains a sensitive value, you should remove the saml.yaml file immediately after updating the resource. -
Edit
saml.yaml
, addingkube-access
to theattributes_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
-
Apply your changes:
tctl create -f saml.yaml -
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Retrieve your
oidc
configuration resource:tctl get oidc/myoidc --with-secrets > oidc.yamlNote that the
--with-secrets
flag adds the value ofspec.signing_key_pair.private_key
to theoidc.yaml
file. Because this key contains a sensitive value, you should remove the oidc.yaml file immediately after updating the resource. -
Edit
oidc.yaml
, addingkube-access
to theclaims_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
-
Apply your changes:
tctl create -f oidc.yaml -
Sign out of the Teleport cluster and sign in again to assume the new role.
-
-
Configure the
viewers
group in your Kubernetes cluster to have the built-inview
ClusterRole. When your Teleport user assumes thekube-access
role and sends requests to the Kubernetes API server, the Teleport Kubernetes Service impersonates theviewers
group and proxies the requests.Create a file called
viewers-bind.yaml
with the following contents, binding the built-inview
ClusterRole with theviewers
group you enabled your Teleport user to access: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
withkubectl
:kubectl apply -f viewers-bind.yaml
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:
-
Retrieve your local user's roles as a comma-separated list:
ROLES=$(tsh status -f json | jq -r '.active.roles | join(",")') -
Edit your local user to add the new role:
tctl users update $(tsh status -f json | jq -r '.active.username') \ --set-roles "${ROLES?},kube-manager" -
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Open your
github
authentication connector in a text editor:tctl edit github/github -
Edit the
github
connector, addingkube-manager
to theteams_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-manager
-
Apply your changes by saving closing the file in your editor.
-
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Retrieve your
saml
configuration resource:tctl get --with-secrets saml/mysaml > saml.yamlNote that the
--with-secrets
flag adds the value ofspec.signing_key_pair.private_key
to thesaml.yaml
file. Because this key contains a sensitive value, you should remove the saml.yaml file immediately after updating the resource. -
Edit
saml.yaml
, addingkube-manager
to theattributes_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-manager
-
Apply your changes:
tctl create -f saml.yaml -
Sign out of the Teleport cluster and sign in again to assume the new role.
-
Retrieve your
oidc
configuration resource:tctl get oidc/myoidc --with-secrets > oidc.yamlNote that the
--with-secrets
flag adds the value ofspec.signing_key_pair.private_key
to theoidc.yaml
file. Because this key contains a sensitive value, you should remove the oidc.yaml file immediately after updating the resource. -
Edit
oidc.yaml
, addingkube-manager
to theclaims_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-manager
-
Apply your changes:
tctl create -f oidc.yaml -
Sign out of the Teleport cluster and sign in again to assume the new role.
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-contextsAssign 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/v16.4.10/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
You can add labels to the kube_cluster
resource, allowing you to manage access
to specific clusters from your Teleport roles or Kubernetes Service instances.
Labels can either be static or dynamic. Static labels are key/value pairs. This
example defines the env=prod
and team=dev
labels:
kind: kube_cluster
version: v3
metadata:
name: mycluster
labels:
env: prod
team: dev
spec:
kubeconfig: KUBECONFIG
You can also add dynamic labels, which define shell commands that a Kubernetes
Service instance will execute in order to generate labels. To do so, edit the
spec.dynamic_labels
field of a kube_cluster
resource.
This example runs the python3 get_region.py
command to fetch the region in
which the Kubernetes Service is deployed and assign the result to the region
key:
kind: kube_cluster
version: v3
metadata:
name: mycluster
spec:
kubeconfig: KUBECONFIG
dynamic_labels:
region:
period: "24h"
command: ["python3", "get_region.py"]
When defining a dynamic label, the key within the spec.dynamic_labels
field
behaves the same as keys within the metadata.labels
field, indicating the key
of the label.
The Kubernetes Service obtains a value for that key by running the
command given in command
every period
. command
is an array of strings,
where the first element indicates the command to execute and each subsequent
element indicates an argument.
period
is a Go duration string, which includes a number and a unit of time.
Supported units are ns
, us
(or µs
), ms
, s
, m
, and h
. The example
above configures the Kubernetes Service to run the command every day.
To create the kube_cluster
resource, run the following command:
tctl create kube_cluster.yamlkubernetes 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 lsKube 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 myclusterLogged 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 open the resource as it exists on the Auth Service's backend in your
text editor:
tctl edit kube_clusters/mycluster
Edit the resource 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
Save and close the file in your editor to apply your changes.
You should now see the updated labels:
tsh kube lsKube Cluster Name Labels Selected ----------------- ------------------------------------ -------- mycluster env=test teleport.dev/origin=dynamic *
If the updated kube_cluster
resource's labels no longer match the ones a Teleport
Kubernetes Service instance is configured to watch, the instance will unregister
and stop proxying the Kubernetes cluster.
Delete Kubernetes cluster resources
To delete the kube_cluster
resource you created earlier, run the following
command:
tctl rm kube_clusters/myclusterkubernetes cluster "mycluster" has been deleted
This will unregister the Kubernetes cluster from Teleport:
tsh kube lsKube 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.