Federated Cluster
This guide explains how to use Clusters API resource in a Federation control plane.
Different than other Kuberentes resources, such as Deployments, Services and ConfigMaps, clusters only exist in the federation context, i.e. those requests must be submitted to the federation api-server.
- Before you begin
- Listing Clusters
- Creating a Federated Cluster
- Deleting a Federated Cluster
- Clusters API reference
Before you begin
- This guide assumes that you have a running Kubernetes Cluster Federation installation. If not, then head over to the federation admin guide to learn how to bring up a cluster federation (or have your cluster administrator do this for you). Other tutorials, such as Kelsey Hightower’s Federated Kubernetes Tutorial, might also help you create a Federated Kubernetes cluster.
- You should also have a basic working knowledge of Kubernetes in general.
Listing Clusters
To list the clusters available in your federation, you can use kubectl by running:
kubectl --context=federation get clusters
The --context=federation flag tells kubectl to submit the
request to the Federation apiserver instead of sending it to a Kubernetes
cluster. If you submit it to a k8s cluster, you will receive an error saying
the server doesn't have a resource type "clusters"
If you passed the correct Federation context but received a message error saying
No resources found., it means that you haven’t
added any cluster to the Federation yet.
Creating a Federated Cluster
Creating a cluster resource in federation means joining it to the federation. To do so, you can use
kubefed join. Basically, you need to give the new cluster a name and say what is the name of the
context that corresponds to a cluster that hosts the federation. The following example command adds
the cluster gondor to the federation running on host cluster rivendell:
kubefed join gondor --host-cluster-context=rivendell
You can find more details on how to do that in the respective section in the kubefed guide.
Deleting a Federated Cluster
Converse to creating a cluster, deleting a cluster means unjoining this cluster from the
federation. This can be done with kubefed unjoin command. To remove the gondor cluster, just do:
kubefed unjoin gondor --host-cluster-context=rivendell
You can find more details on unjoin in the kubefed guide.
Clusters API reference
The full clusters API reference is currently in federation/v1beta1 and more details can be found in details in the
Federation API reference page.