Use a bootstrap token as a temporary bearer credential when authenticating a node to the Kubernetes API during cluster joining. kubeadm creates an initial token with a 24-hour lifetime and can generate additional tokens on demand. During node joining, the token helps establish bidirectional trust between the joining node and a control-plane node. section 5.2.2
Recreate a node join command
Generate a usable join command with `kubeadm token create --print-join-command`. Run the resulting `kubeadm join` command on the missing worker, then verify the result with `kubectl get nodes` and confirm the node reaches `Ready`. section 5.2.2
