CreateDefaultKubeConfigsAndCSRFiles is used in ExternalCA mode to create kubeconfig files and adjacent CSR files.

CreateJoinControlPlaneKubeConfigFiles will create and write to disk the kubeconfig files required by kubeadm join --control-plane workflow, plus the admin kubeconfig file used by the administrator and kubeadm itself; the kubelet.conf file must not be created because it will be created and signed by the kubelet TLS bootstrap process.

CreateKubeConfigFile creates a kubeconfig file.

EnsureAdminClusterRoleBinding constructs a client from admin.conf and optionally constructs a client from super-admin.conf if the file exists.

EnsureAdminClusterRoleBindingImpl first attempts to see if the ClusterRoleBinding kubeadm:cluster-admins exists by using adminClient.

ValidateKubeconfigsForExternalCA check if the kubeconfig file exist and has the expected CA and server URL using kubeadmapi.InitConfiguration.

WriteKubeConfigWithClientCert writes a kubeconfig file - with a client certificate as authentication info - to the given writer.

WriteKubeConfigWithToken writes a kubeconfig file - with a token as client authentication info - to the given writer.

EnsureRBACFunc defines a function type that can be passed to EnsureAdminClusterRoleBinding().