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kubeadm init phase

kubeadm init phase enables you to invoke atomic steps of the bootstrap process. Hence, you can let kubeadm do some of the work and you can fill in the gaps if you wish to apply customization.

kubeadm init phase is consistent with the kubeadm init workflow, and behind the scene both use the same code.

kubeadm init phase preflight

Using this command you can execute preflight checks on a control-plane node.

Synopsis

Run pre-flight checks for kubeadm init.

kubeadm init phase preflight [flags]

Examples

  # Run pre-flight checks for kubeadm init using a config file.
  kubeadm init phase preflight --config kubeadm-config.yml

Options

--config string
Path to a kubeadm configuration file.
-h, --help
help for preflight
--ignore-preflight-errors stringSlice
A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.

Options inherited from parent commands

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

kubeadm init phase kubelet-start

This phase will write the kubelet configuration file and environment file and then start the kubelet.

Synopsis

Write a file with KubeletConfiguration and an environment file with node specific kubelet settings, and then (re)start kubelet.

kubeadm init phase kubelet-start [flags]

Examples

  # Writes a dynamic environment file with kubelet flags from a InitConfiguration file.
  kubeadm init phase kubelet-start --config config.yaml

Options

--config string
Path to a kubeadm configuration file.
--cri-socket string
Path to the CRI socket to connect. If empty kubeadm will try to auto-detect this value; use this option only if you have more than one CRI installed or if you have non-standard CRI socket.
-h, --help
help for kubelet-start
--node-name string
Specify the node name.

Options inherited from parent commands

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

kubeadm init phase certs

Can be used to create all required certificates by kubeadm.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase certs [flags]

Options

-h, --help
help for certs

Options inherited from parent commands

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

kubeadm init phase kubeconfig

You can create all required kubeconfig files by calling the all subcommand or call them individually.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase kubeconfig [flags]

Options

-h, --help
help for kubeconfig

Options inherited from parent commands

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

kubeadm init phase control-plane

Using this phase you can create all required static Pod files for the control plane components.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase control-plane [flags]

Options

-h, --help
help for control-plane

Options inherited from parent commands

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

kubeadm init phase etcd

Use the following phase to create a local etcd instance based on a static Pod file.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase etcd [flags]

Options

-h, --help
help for etcd

Options inherited from parent commands

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

kubeadm init phase upload-config

You can use this command to upload the kubeadm configuration to your cluster. Alternatively, you can use kubeadm config.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase upload-config [flags]

Options

-h, --help
help for upload-config

Options inherited from parent commands

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

kubeadm init phase upload-certs

Use the following phase to upload control-plane certificates to the cluster. By default the certs and encryption key expire after two hours.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase upload-certs [flags]

Options

--certificate-key string
Key used to encrypt the control-plane certificates in the kubeadm-certs Secret.
--config string
Path to a kubeadm configuration file.
-h, --help
help for upload-certs
--skip-certificate-key-print
Don't print the key used to encrypt the control-plane certificates.
--upload-certs
Upload control-plane certificates to the kubeadm-certs Secret.

Options inherited from parent commands

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

kubeadm init phase mark-control-plane

Use the following phase to label and taint the node with the node-role.kubernetes.io/master="" key-value pair.

Synopsis

Mark a node as a control-plane

kubeadm init phase mark-control-plane [flags]

Examples

  # Applies control-plane label and taint to the current node, functionally equivalent to what executed by kubeadm init.
  kubeadm init phase mark-control-plane --config config.yml
  
  # Applies control-plane label and taint to a specific node
  kubeadm init phase mark-control-plane --node-name myNode

Options

--config string
Path to a kubeadm configuration file.
-h, --help
help for mark-control-plane
--node-name string
Specify the node name.

Options inherited from parent commands

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

kubeadm init phase bootstrap-token

Use the following phase to configure bootstrap tokens.

Synopsis

Bootstrap tokens are used for establishing bidirectional trust between a node joining the cluster and a control-plane node.

This command makes all the configurations required to make bootstrap tokens works and then creates an initial token.

kubeadm init phase bootstrap-token [flags]

Examples

  # Make all the bootstrap token configurations and create an initial token, functionally
  # equivalent to what generated by kubeadm init.
  kubeadm init phase bootstrap-token

Options

--config string
Path to a kubeadm configuration file.
-h, --help
help for bootstrap-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.
--skip-token-print
Skip printing of the default bootstrap token generated by 'kubeadm init'.

Options inherited from parent commands

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

kubeadm init phase addon

You can install all the available addons with the all subcommand, or install them selectively.

Synopsis

This command is not meant to be run on its own. See list of available subcommands.

kubeadm init phase addon [flags]

Options

-h, --help
help for addon

Options inherited from parent commands

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

To use kube-dns instead of CoreDNS you have to pass a configuration file:

# for installing a DNS addon only
kubeadm init phase addon coredns --config=someconfig.yaml
# for creating a complete control plane node
kubeadm init --config=someconfig.yaml
# for listing or pulling images
kubeadm config images list/pull --config=someconfig.yaml
# for upgrades
kubeadm upgrade apply --config=someconfig.yaml

The file has to contain a DNS field inClusterConfiguration and also a type for the addon - kube-dns (default value is CoreDNS).

apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
dns:
  type: "kube-dns"

Please note that kube-dns usage with kubeadm is deprecated as of v1.18 and will be removed in a future release.

For more details on each field in the v1beta2 configuration you can navigate to our API reference pages.

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