You are viewing documentation for Kubernetes version: v1.26

Kubernetes v1.26 documentation is no longer actively maintained. The version you are currently viewing is a static snapshot. For up-to-date information, see the latest version.

Manage bootstrap tokens

Synopsis

This command manages bootstrap tokens. It is optional and needed only for advanced use cases.

In short, bootstrap tokens are used for establishing bidirectional trust between a client and a server. A bootstrap token can be used when a client (for example a node that is about to join the cluster) needs to trust the server it is talking to. Then a bootstrap token with the "signing" usage can be used. bootstrap tokens can also function as a way to allow short-lived authentication to the API Server (the token serves as a way for the API Server to trust the client), for example for doing the TLS Bootstrap.

What is a bootstrap token more exactly?

  • It is a Secret in the kube-system namespace of type "bootstrap.kubernetes.io/token".
  • A bootstrap token must be of the form "[a-z0-9]{6}.[a-z0-9]{16}". The former part is the public token ID, while the latter is the Token Secret and it must be kept private at all circumstances!
  • The name of the Secret must be named "bootstrap-token-(token-id)".

You can read more about bootstrap tokens here: https://kubernetes.io/docs/admin/bootstrap-tokens/

kubeadm token [flags]

Options

--dry-run

Whether to enable dry-run mode or not

-h, --help

help for token

--kubeconfig string     Default: "/etc/kubernetes/admin.conf"

The kubeconfig file to use when talking to the cluster. If the flag is not set, a set of standard locations can be searched for an existing kubeconfig file.

Options inherited from parent commands

--rootfs string

[EXPERIMENTAL] The path to the 'real' host root filesystem.

Last modified August 24, 2022 at 9:22 AM PST: kubeadm reference for 1.25 (09506daf64)