kubectl get nodes
NAME         STATUS   ROLES    AGE    VERSION
i-6fns0nua   Ready    master   6d3h   v1.15.2
i-m69skuyd   Ready    <none>   6d2h   v1.15.2

kubectl label node i-m69skuyd  node-role.kubernetes.io/worker=
node/i-m69skuyd labeled

kubectl get node
NAME         STATUS   ROLES    AGE    VERSION
i-6fns0nua   Ready    master   6d3h   v1.15.2
i-m69skuyd   Ready    worker   6d2h   v1.15.2