kubernetes/cmd/kubeadm/app/util/config/cluster.go

// FetchInitConfigurationFromCluster fetches configuration from a ConfigMap in the cluster
func FetchInitConfigurationFromCluster(client clientset.Interface, printer output.Printer, logPrefix string, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) { … }

// getInitConfigurationFromCluster is separate only for testing purposes, don't call it directly, use FetchInitConfigurationFromCluster instead
func getInitConfigurationFromCluster(kubeconfigDir string, client clientset.Interface, newControlPlane, skipComponentConfigs bool) (*kubeadmapi.InitConfiguration, error) { … }

// GetNodeRegistration returns the nodeRegistration for the current node
func GetNodeRegistration(kubeconfigFile string, client clientset.Interface, nodeRegistration *kubeadmapi.NodeRegistrationOptions) error { … }

// getNodeNameFromKubeletConfig gets the node name from a kubelet config file
// TODO: in future we want to switch to a more canonical way for doing this e.g. by having this
// information in the local kubelet config.yaml
func getNodeNameFromKubeletConfig(fileName string) (string, error) { … }

func getAPIEndpoint(client clientset.Interface, nodeName string, apiEndpoint *kubeadmapi.APIEndpoint) error { … }

func getAPIEndpointWithRetry(client clientset.Interface, nodeName string, apiEndpoint *kubeadmapi.APIEndpoint,
	interval, timeout time.Duration) error { … }

func getAPIEndpointFromPodAnnotation(client clientset.Interface, nodeName string, apiEndpoint *kubeadmapi.APIEndpoint,
	interval, timeout time.Duration) error { … }

func getRawAPIEndpointFromPodAnnotationWithoutRetry(ctx context.Context, client clientset.Interface, nodeName string) (string, error) { … }