ServiceClusters

ServiceClusters are Kubernetes clusters that run the actual application workloads managed by their operators, which are driven by the KubeCarrier Service Hub. To allow that, they first have to be registered in the KubeCarrier Management Cluster.

To register a new Service Cluster in KubeCarrier, we will need another Kubernetes cluster and its Kubeconfig.

Need another Cluster?

If you don’t have another Kubernetes Cluster, just go back to Requirements and create another cluster with Kind. In this example we will use the name eu-west-1 for this new cluster.

When you create another cluster with Kind, you have to work with the internal Kubeconfig of the cluster, see command below:

kind get kubeconfig --internal --name eu-west-1 > /tmp/eu-west-1-kubeconfig

This will replace the default localhost:xxxx address with the container’s IP address, allowing KubeCarrier to talk with the other kind cluster.

When creating a new cluster with kind your active context will be switched to the newly created cluster. Check kubectl config current-context and use kubectl config use-context to switch back to the right cluster.

Add a ServiceCluster

To add a new Service Cluster, we first have to upload its Kubeconfig as a Secret into our Account Namespace.

Management Cluster

$ kubectl create secret generic eu-west-1-kubeconfig \
  -n team-a \
  --from-file=kubeconfig=/tmp/eu-west-1-kubeconfig
secret/eu-west-1-kubeconfig created

Now that we have the credentials and connection information, we can register the Cluster into KubeCarrier.

apiVersion: kubecarrier.io/v1alpha1
kind: ServiceCluster
metadata:
  name: eu-west-1
spec:
  metadata:
    displayName: EU West 1
  kubeconfigSecret:
    name: eu-west-1-kubeconfig

You can create the above ServiceCluster CR object with:

Management Cluster

$ kubectl apply -n team-a \
  -f https://raw.githubusercontent.com/kubermatic/kubecarrier/master/docs/manifests/servicecluster.yaml
servicecluster.kubecarrier.io/team-a created

$ kubectl get servicecluster -n team-a
NAME        STATUS   DISPLAY NAME   KUBERNETES VERSION   AGE
eu-west-1   Ready    EU West 1      v1.17.0              8s

KubeCarrier will connect to the Cluster, do basic health checking and report the Kubernetes Version.