# kubeadm join phase LLMS index: [llms.txt](/llms.txt) --- `kubeadm join phase` enables you to invoke atomic steps of the join 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 join phase` is consistent with the [kubeadm join workflow](/docs/reference/setup-tools/kubeadm/kubeadm-join/#join-workflow), and behind the scene both use the same code. ## kubeadm join phase {#cmd-join-phase}

Synopsis

Use this command to invoke single phase of the "join" workflow

kubeadm join phase [flags]

Options

-h, --help

help for phase

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase preflight {#cmd-join-phase-preflight} Using this phase you can execute preflight checks on a joining node.

Run join pre-flight checks

Synopsis

Run pre-flight checks for kubeadm join.

kubeadm join phase preflight [api-server-endpoint] [flags]

Examples

  # Run join pre-flight checks using a config file.
  kubeadm join phase preflight --config kubeadm-config.yaml

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32     Default: 6443

If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string

Use this key to decrypt the certificate secrets uploaded by init. The certificate key is a hex encoded string that is an AES key of size 32 bytes.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--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.
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for preflight
--ignore-preflight-errors strings

A list of checks whose errors will be shown as warnings. Example: 'IsPrivilegedUser,Swap'. Value 'all' ignores errors from all checks.
--node-name string

Specify the node name.
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase control-plane-prepare {#cmd-join-phase-control-plane-prepare} Using this phase you can prepare a node for serving a control-plane.

Synopsis

Prepare the machine for serving a control plane

kubeadm join phase control-plane-prepare [flags]

Examples

  # Prepares the machine for serving a control plane
  kubeadm join phase control-plane-prepare all

Options

-h, --help

help for control-plane-prepare

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Prepare the machine for serving a control plane

kubeadm join phase control-plane-prepare all [api-server-endpoint] [flags]

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32     Default: 6443

If the node should host a new control plane instance, the port for the API Server to bind to.
--certificate-key string

Use this key to decrypt the certificate secrets uploaded by init. The certificate key is a hex encoded string that is an AES key of size 32 bytes.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for all
--node-name string

Specify the node name.
--patches string

Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration", "corednsdeployment". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Download certificates shared among control-plane nodes from the kubeadm-certs Secret

kubeadm join phase control-plane-prepare download-certs [api-server-endpoint] [flags]

Options

--certificate-key string

Use this key to decrypt the certificate secrets uploaded by init. The certificate key is a hex encoded string that is an AES key of size 32 bytes.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for download-certs
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Generate the certificates for the new control plane components

kubeadm join phase control-plane-prepare certs [api-server-endpoint] [flags]

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for certs
--node-name string

Specify the node name.
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Generate the kubeconfig for the new control plane components

kubeadm join phase control-plane-prepare kubeconfig [api-server-endpoint] [flags]

Options

--certificate-key string

Use this key to decrypt the certificate secrets uploaded by init. The certificate key is a hex encoded string that is an AES key of size 32 bytes.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for kubeconfig
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Generate the manifests for the new control plane components

kubeadm join phase control-plane-prepare control-plane [flags]

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--apiserver-bind-port int32     Default: 6443

If the node should host a new control plane instance, the port for the API Server to bind to.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for control-plane
--patches string

Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration", "corednsdeployment". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase kubelet-start {#cmd-join-phase-kubelet-start} Using this phase you can write the kubelet settings, certificates and (re)start the kubelet.

Write kubelet settings, certificates and (re)start the kubelet

Synopsis

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

kubeadm join phase kubelet-start [api-server-endpoint] [flags]

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.
--discovery-file string

For file-based discovery, a file or URL from which to load cluster information.
--discovery-token string

For token-based discovery, the token used to validate cluster information fetched from the API server.
--discovery-token-ca-cert-hash strings

For token-based discovery, validate that the root CA public key matches this hash (format: "<type>:<value>").
--discovery-token-unsafe-skip-ca-verification

For token-based discovery, allow joining without --discovery-token-ca-cert-hash pinning.
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for kubelet-start
--node-name string

Specify the node name.
--patches string

Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration", "corednsdeployment". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.
--tls-bootstrap-token string

Specify the token used to temporarily authenticate with the Kubernetes Control Plane while joining the node.
--token string

Use this token for both discovery-token and tls-bootstrap-token when those values are not provided.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase etcd-join {#cmd-join-phase-etcd-join} Join the new etcd member to the etcd cluster.

Synopsis

Join etcd for control plane nodes

kubeadm join phase etcd-join [flags]

Examples

  # Joins etcd for a control plane instance
  kubeadm join phase control-plane-join-etcd all

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for etcd-join
--node-name string

Specify the node name.
--patches string

Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration", "corednsdeployment". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase control-plane-join {#cmd-join-phase-control-plane-join} Using this phase you can join a node as a control-plane instance.

Synopsis

Join a machine as a control plane instance

kubeadm join phase control-plane-join [flags]

Examples

  # Joins a machine as a control plane instance
  kubeadm join phase control-plane-join all

Options

-h, --help

help for control-plane-join

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Join a machine as a control plane instance

kubeadm join phase control-plane-join all [flags]

Options

--apiserver-advertise-address string

If the node should host a new control plane instance, the IP address the API Server will advertise it's listening on. If not set the default network interface will be used.
--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for all
--node-name string

Specify the node name.
--patches string

Path to a directory that contains files named "target[suffix][+patchtype].extension". For example, "kube-apiserver0+merge.yaml" or just "etcd.json". "target" can be one of "kube-apiserver", "kube-controller-manager", "kube-scheduler", "etcd", "kubeletconfiguration", "corednsdeployment". "patchtype" can be one of "strategic", "merge" or "json" and they match the patch formats supported by kubectl. The default "patchtype" is "strategic". "extension" must be either "json" or "yaml". "suffix" is an optional string that can be used to determine which patches are applied first alpha-numerically.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.

Synopsis

Mark a node as a control-plane

kubeadm join phase control-plane-join mark-control-plane [flags]

Options

--config string

Path to a kubeadm configuration file.
--control-plane

Create a new control plane instance on this node
--dry-run

Don't apply any changes; just output what would be done.
-h, --help

help for mark-control-plane
--node-name string

Specify the node name.

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## kubeadm join phase wait-control-plane {#cmd-join-wait-control-plane} Wait for the control plane components to start.

Synopsis

Wait for the control plane to start

kubeadm join phase wait-control-plane [flags]

Options

-h, --help

help for wait-control-plane

Options inherited from parent commands

--rootfs string

The path to the 'real' host root filesystem. This will cause kubeadm to chroot into the provided path.
## What's next * [kubeadm init](/docs/reference/setup-tools/kubeadm/kubeadm-init/) to bootstrap a Kubernetes control-plane node * [kubeadm join](/docs/reference/setup-tools/kubeadm/kubeadm-join/) to connect a node to the cluster * [kubeadm reset](/docs/reference/setup-tools/kubeadm/kubeadm-reset/) to revert any changes made to this host by `kubeadm init` or `kubeadm join` * [kubeadm alpha](/docs/reference/setup-tools/kubeadm/kubeadm-alpha/) to try experimental functionality