Attach Amazon EKS Cluster to Kommander

Attach an existing EKS cluster to Kommander

You can attach existing Kubernetes clusters to Kommander. After attaching the cluster, you can use Kommander to examine and manage this cluster. The following procedure shows how to attach an existing Amazon Elastic Kubernetes Service (EKS) cluster to Kommander.

Before you begin

This procedure requires the following items and configurations:

NOTE: This procedure assumes you have an existing and spun up Amazon EKS cluster(s) with administrative privileges. Refer to the Amazon EKS for setup and configuration information.

Attach Amazon EKS Clusters to Kommander

  1. Ensure you are connected to your EKS clusters. Enter the following commands for each of your clusters:

    kubectl config get-contexts
kubectl config use-context <context for first eks cluster>

  2. Confirm kubectl can access the EKS cluster.

    kubectl get nodes

  3. Create a service account for Kommander on your EKS cluster.

    kubectl -n kube-system create serviceaccount kommander-cluster-admin

  4. Configure your kommander-cluster-admin service account to have cluster-admin permissions. Enter the following command:

    cat << EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kommander-cluster-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kommander-cluster-admin
  namespace: kube-system
EOF

  5. You must create a kubeconfig file that is compatible with the Kommander UI. Enter these commands to set the following environment variables:

    export USER_TOKEN_NAME=$(kubectl -n kube-system get serviceaccount kommander-cluster-admin -o=jsonpath='{.secrets[0].name}')
export USER_TOKEN_VALUE=$(kubectl -n kube-system get secret/${USER_TOKEN_NAME} -o=go-template='{{.data.token}}' | base64 --decode)
export CURRENT_CONTEXT=$(kubectl config current-context)
export CURRENT_CLUSTER=$(kubectl config view --raw -o=go-template='{{range .contexts}}{{if eq .name "'''${CURRENT_CONTEXT}'''"}}{{ index .context "cluster" }}{{end}}{{end}}')
export CLUSTER_CA=$(kubectl config view --raw -o=go-template='{{range .clusters}}{{if eq .name "'''${CURRENT_CLUSTER}'''"}}{{ index .cluster "certificate-authority-data" }}{{end}}{{ end }}')
export CLUSTER_SERVER=$(kubectl config view --raw -o=go-template='{{range .clusters}}{{if eq .name "'''${CURRENT_CLUSTER}'''"}}{{ .cluster.server }}{{end}}{{ end }}')

  6. Confirm these variables have been set correctly:

    env | grep CLUSTER

  7. Create your kubeconfig file to use in the Kommander UI. Enter the following commands:

    cat << EOF > kommander-cluster-admin-config
apiVersion: v1
kind: Config
current-context: ${CURRENT_CONTEXT}
contexts:
- name: ${CURRENT_CONTEXT}
  context:
    cluster: ${CURRENT_CONTEXT}
    user: kommander-cluster-admin
    namespace: kube-system
clusters:
- name: ${CURRENT_CONTEXT}
  cluster:
    certificate-authority-data: ${CLUSTER_CA}
    server: ${CLUSTER_SERVER}
users:
- name: kommander-cluster-admin
  user:
    token: ${USER_TOKEN_VALUE}
EOF

  8. Verify the kubeconfig file can access the EKS cluster.

    kubectl --kubeconfig $(pwd)/kommander-cluster-admin-config get all --all-namespaces

  9. Copy kommander-cluster-admin-config file contents to your clipboard.

    cat kommander-cluster-admin-config | pbcopy

NOTE: If you are not using the Mac OS X operating system, this command will not work. If you are using the Linux operating system, enter the following command:
cat kommander-cluster-admin-config | xclip -selection clipboard

Now that you have kubeconfig, go to the Kommander UI and follow these steps below:

  1. Select Clusters from the left sidebar navigation, and then select the Add Cluster button in your Kommander window.

  2. Select the Attach Cluster button.

  3. Select the No additional networking restrictions card to display the Cluster Configuration dialog box. This dialog box accepts a kubeconfig file that you can paste, or upload, into the field.

  4. Paste the contents of your clipboard (or upload the file you created) into the Kubeconfig File text box.

  5. Assign a name and add any desired labels for the cluster.

  6. Confirm you are assigning the cluster to your desired workspace.

  7. Select the Submit button.

NOTE: If a cluster has limited resources to deploy all the federated platform services, it will fail to stay attached in the Kommander UI. If this happens, ensure your system has sufficient resources for all pods.

For information on related topics or procedures, refer to the following: