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Reference

Kubernetes v1.13 documentation is no longer actively maintained. The version you are currently viewing is a static snapshot. For up-to-date documentation, see the latest version.

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kubeadm config

Beginning with v1.8.0, kubeadm uploads the configuration of your cluster to a ConfigMap called kubeadm-config in the kube-system namespace, and later reads the ConfigMap when upgrading. This enables correct configuration of system components, and provides a seamless user experience.

You can execute kubeadm config view to view the ConfigMap. If you initialized your cluster using kubeadm v1.7.x or lower, you must use kubeadm config upload to create the ConfigMap before you may use kubeadm upgrade.

In Kubernetes v1.11.0, some new commands were added. You can use kubeadm config print-default to print the default configuration and kubeadm config migrate to convert your old configuration files to a newer version. kubeadm config images list and kubeadm config images pull can be used to list and pull the images that kubeadm requires.

In Kubernetes v1.13.0 and later to list/pull kube-dns images instead of the CoreDNS image the --config method described here has to be used.

kubeadm config upload from-file
kubeadm config upload from-flags
kubeadm config view
kubeadm config print init-defaults
kubeadm config print join-defaults
kubeadm config migrate
kubeadm config images list
kubeadm config images pull
What's next

kubeadm config upload from-file

Upload a configuration file to the in-cluster ConfigMap for kubeadm configuration.

Synopsis

Using this command, you can upload configuration to the ConfigMap in the cluster using the same config file you gave to ‘kubeadm init’. If you initialized your cluster using a v1.7.x or lower kubeadm client and used the –config option, you need to run this command with the same config file before upgrading to v1.8 using ‘kubeadm upgrade’.

The configuration is located in the “kube-system” namespace in the “kubeadm-config” ConfigMap.

kubeadm config upload from-file [flags]

Options

--config string
	Path to a kubeadm config file. WARNING: Usage of a configuration file is experimental.
-h, --help
	help for from-file

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config upload from-flags

Create the in-cluster configuration file for the first time from using flags.

Synopsis

Using this command, you can upload configuration to the ConfigMap in the cluster using the same flags you gave to ‘kubeadm init’. If you initialized your cluster using a v1.7.x or lower kubeadm client and set certain flags, you need to run this command with the same flags before upgrading to v1.8 using ‘kubeadm upgrade’.

The configuration is located in the “kube-system” namespace in the “kubeadm-config” ConfigMap.

kubeadm config upload from-flags [flags]

Options

--apiserver-advertise-address string
	The IP address the API Server will advertise it's listening on. Specify '0.0.0.0' to use the address of the default network interface.
--apiserver-bind-port int32 Default: 6443
	Port for the API Server to bind to.
--apiserver-cert-extra-sans stringSlice
	Optional extra Subject Alternative Names (SANs) to use for the API Server serving certificate. Can be both IP addresses and DNS names.
--cert-dir string Default: "/etc/kubernetes/pki"
	The path where to save and store the certificates.
--cri-socket string Default: "/var/run/dockershim.sock"
	Specify the CRI socket to connect to.
--feature-gates string
	A set of key=value pairs that describe feature gates for various features. Options are:
-h, --help
	help for from-flags
--kubernetes-version string Default: "stable-1"
	Choose a specific Kubernetes version for the control plane.
--node-name string
	Specify the node name.
--pod-network-cidr string
	Specify range of IP addresses for the pod network. If set, the control plane will automatically allocate CIDRs for every node.
--service-cidr string Default: "10.96.0.0/12"
	Use alternative range of IP address for service VIPs.
--service-dns-domain string Default: "cluster.local"
	Use alternative domain for services, e.g. "myorg.internal".

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config view

View the kubeadm configuration stored inside the cluster.

Synopsis

Using this command, you can view the ConfigMap in the cluster where the configuration for kubeadm is located.

The configuration is located in the “kube-system” namespace in the “kubeadm-config” ConfigMap.

kubeadm config view [flags]

Options

-h, --help
	help for view

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config print init-defaults

Print default init configuration, that can be used for ‘kubeadm init’

Synopsis

This command prints objects such as the default init configuration that is used for ‘kubeadm init’.

Note that sensitive values like the Bootstrap Token fields are replaced with placeholder values like {“abcdef.0123456789abcdef” “” “nil” [] []} in order to pass validation but not perform the real computation for creating a token.

kubeadm config print init-defaults [flags]

Options

--component-configs stringSlice
	A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
-h, --help
	help for init-defaults

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config print join-defaults

Print default join configuration, that can be used for ‘kubeadm join’

Synopsis

This command prints objects such as the default join configuration that is used for ‘kubeadm join’.

kubeadm config print join-defaults [flags]

Options

--component-configs stringSlice
	A comma-separated list for component config API objects to print the default values for. Available values: [KubeProxyConfiguration KubeletConfiguration]. If this flag is not set, no component configs will be printed.
-h, --help
	help for join-defaults

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config migrate

Read an older version of the kubeadm configuration API types from a file, and output the similar config object for the newer version.

Synopsis

This command lets you convert configuration objects of older versions to the latest supported version, locally in the CLI tool without ever touching anything in the cluster. In this version of kubeadm, the following API versions are supported: - kubeadm.k8s.io/v1alpha3 - kubeadm.k8s.io/v1beta1

Further, kubeadm can only write out config of version “kubeadm.k8s.io/v1beta1”, but read both types. So regardless of what version you pass to the –old-config parameter here, the API object will be read, deserialized, defaulted, converted, validated, and re-serialized when written to stdout or –new-config if specified.

In other words, the output of this command is what kubeadm actually would read internally if you submitted this file to “kubeadm init”

kubeadm config migrate [flags]

Options

-h, --help
	help for migrate
--new-config string
	Path to the resulting equivalent kubeadm config file using the new API version. Optional, if not specified output will be sent to STDOUT.
--old-config string
	Path to the kubeadm config file that is using an old API version and should be converted. This flag is mandatory.

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config images list

Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized.

Synopsis

Print a list of images kubeadm will use. The configuration file is used in case any images or image repositories are customized.

kubeadm config images list [flags]

Options

--config string
	Path to kubeadm config file.
--feature-gates string
	A set of key=value pairs that describe feature gates for various features. Options are:
-h, --help
	help for list
--kubernetes-version string Default: "stable-1"
	Choose a specific Kubernetes version for the control plane.

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

kubeadm config images pull

Pull images used by kubeadm.

Synopsis

Pull images used by kubeadm.

kubeadm config images pull [flags]

Options

--config string
	Path to kubeadm config file.
--cri-socket string Default: "/var/run/dockershim.sock"
	Specify the CRI socket to connect to.
--feature-gates string
	A set of key=value pairs that describe feature gates for various features. Options are:
-h, --help
	help for pull
--kubernetes-version string Default: "stable-1"
	Choose a specific Kubernetes version for the control plane.

Options inherited from parent commands

--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 are searched for an existing KubeConfig file.
--rootfs string
	[EXPERIMENTAL] The path to the 'real' host root filesystem.

What's next

kubeadm upgrade to upgrade a Kubernetes cluster to a newer version

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