How to add an additional kubernetes config file to your current one

How to add an additional kubernetes config file to your current one (located in ~./kube/config)

1. Backup the existing kubeconfig

   Before making any changes, it's essential to back up your existing kubeconfig file.

   cp ~/.kube/config ~/.kube/config.backup

2. Set the new names

   Define the new user name, cluster name, and the path to the new kubeconfig file. Update these variables as needed.

   USER_NAME="user-name"
   CLUSTER_NAME="cluster-name"
   NEW_CLUSTER_CONFIG_FILE="path-to-new-config-file-and-file-name"

3. Update the kubeconfig file

   Replace the default values in the new kubeconfig file with the specified names using the following sed command:

   sed -i -e "s/kubernetes-admin@kubernetes/${USER_NAME}@${CLUSTER_NAME}/g" \
          -e "s/kubernetes-admin/${USER_NAME}/g" \
          -e "s/kubernetes/${CLUSTER_NAME}/g" $NEW_CLUSTER_CONFIG_FILE

4. Set the KUBECONFIG environment variable

   Include both the existing and new kubeconfig files in the KUBECONFIG environment variable:

   export KUBECONFIG=~/.kube/config:$NEW_CLUSTER_CONFIG_FILE

5. Merge the configurations

   Merge the configurations into a temporary file:

   kubectl config view --merge --flatten > /tmp/merged-kubeconfig

6. Check the temporary merged config file

   Verify the contexts in the temporary merged kubeconfig file:

   kubectl config get-contexts --kubeconfig /tmp/merged-kubeconfig

   Ensure the output is correct before proceeding.

7. Move the merged config to overwrite the existing kubeconfig

   If the temporary merged config file is correct, move it to overwrite the existing kubeconfig file:

   mv /tmp/merged-kubeconfig ~/.kube/config

8. Unset the KUBECONFIG environment variable

   Unset the KUBECONFIG environment variable to revert to the default configuration:

   unset KUBECONFIG

9. Verify the new kubeconfig

   Check the contexts in the merged kubeconfig file to ensure it has been updated correctly:

   kubectl config get-contexts
   CURRENT  NAME                                   CLUSTER                               AUTHINFO                               NAMESPACE
            admin-6gxr@6g-xr                       6g-xr                                 admin-6gxr                                                       
            admin-gn5-1@geant-dev                  geant-dev                             admin-gn5-1                                                   
            admin-cilium@kind-cluster-cilium       kind-cluster-cilium                   admin-cilium                                         
   *        admin-kind@kind-kind                   kind-kind                             admin-kind                                                   

10. Switch to another context (optional)

    You can switch to another context using the following command:

    kubectl config use-context <CONTEXT_NAME>