Create a kubeconfig File for your Cluster

If you already have a kubeconfig file, go directly to Attaching a cluster.

To get started, ensure you have kubectl set up and configured with ClusterAdmin for the cluster you want to connect to Kommander.

1. Create the necessary service account:

   CODE

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

2. Create a token secret for the serviceaccount:

   CODE

   kubectl -n kube-system create  -f - <<EOF
   apiVersion: v1
   kind: Secret
   metadata:
     name: kommander-cluster-admin-sa-token
     annotations:
       kubernetes.io/service-account.name: kommander-cluster-admin
   type: kubernetes.io/service-account-token
   EOF

   For more information on Service Account Tokens, refer to this article in our blog.

3. Verify that the serviceaccount token is ready by running this command:

   CODE

   kubectl -n kube-system get secret kommander-cluster-admin-sa-token -oyaml

   Verify that the data.token field is populated. The output should be similar to this:

   NONE

   apiVersion: v1
   data:
     ca.crt: LS0tLS1CRUdJTiBDR...
     namespace: ZGVmYXVsdA==
     token: ZXlKaGJHY2lPaUpTVX...
   kind: Secret
   metadata:
     annotations:
       kubernetes.io/service-account.name: kommander-cluster-admin
       kubernetes.io/service-account.uid: b62bc32e-b502-4654-921d-94a742e273a8
     creationTimestamp: "2022-08-19T13:36:42Z"
     name: kommander-cluster-admin-sa-token
     namespace: default
     resourceVersion: "8554"
     uid: 72c2a4f0-636d-4a70-9f1c-55a75f15e520
   type: kubernetes.io/service-account-token

4. Configure the new service account for cluster-admin permissions:

   NONE

   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. Set up the following environment variables with the access data that is needed for producing a new kubeconfig file:

   NONE

   export USER_TOKEN_VALUE=$(kubectl -n kube-system get secret/kommander-cluster-admin-sa-token -o=go-template='{{.data.token}}' | base64 --decode)
   export CURRENT_CONTEXT=$(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}'''"}}"{{with index .cluster "certificate-authority-data" }}{{.}}{{end}}"{{ 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:

   NONE

   export -p USER_TOKEN_VALUE CURRENT_CONTEXT CURRENT_CLUSTER CLUSTER_CA CLUSTER_SERVER

7. Generate a kubeconfig file that uses the environment variable values from the previous step:

   NONE

   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. This process produces a file in your current working directory called kommander-cluster-admin-config. The contents of this file are used in Kommander to attach the cluster.
   Before importing this configuration, verify the kubeconfig file can access the cluster:

   NONE

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