Merge kube config files by doing the following:
export NEW="/path/to/new/config"
# Backup
cp ~/.kube/config ~/.kube/config.bak
# Flatten
export KUBECONFIG=~/.kube/config:$NEW
kubectl config view --flatten > /tmp/config && mv /tmp/config ~/.kube/config
Verify:
# List clusters
kubectl config get-clusters
kubectl config use-context [name]