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.
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.
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.
--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. If not set the default network interface will be used.
--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
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.
--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.
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.
--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.
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.
--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.
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.
--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’.
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 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.
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.
--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.
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.
--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.
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.
--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
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.
--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.
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.
--rootfs string
[EXPERIMENTAL] The path to the 'real' host root filesystem.
