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

var componentCfgGV …

// documentMapToUpgradeConfiguration takes a map between GVKs and YAML documents (as returned by SplitYAMLDocuments),
// finds a UpgradeConfiguration, decodes it, dynamically defaults it and then validates it prior to return.
func documentMapToUpgradeConfiguration(gvkmap kubeadmapi.DocumentMap, allowDeprecated bool) (*kubeadmapi.UpgradeConfiguration, error) { … }

// DocMapToUpgradeConfiguration converts documentMap to an internal, defaulted and validated UpgradeConfiguration object.
// The map may contain many different YAML documents. These YAML documents are parsed one-by-one
// and well-known ComponentConfig GroupVersionKinds are stored inside of the internal UpgradeConfiguration struct.
// The resulting UpgradeConfiguration is then dynamically defaulted and validated prior to return.
func DocMapToUpgradeConfiguration(gvkmap kubeadmapi.DocumentMap) (*kubeadmapi.UpgradeConfiguration, error) { … }

// LoadUpgradeConfigurationFromFile loads UpgradeConfiguration from a file.
func LoadUpgradeConfigurationFromFile(cfgPath string, _ LoadOrDefaultConfigurationOptions) (*kubeadmapi.UpgradeConfiguration, error) { … }

// LoadOrDefaultUpgradeConfiguration takes a path to a config file and a versioned configuration that can serve as the default config
// If cfgPath is specified, defaultversionedcfg will always get overridden. Otherwise, the default config (often populated by flags) will be used.
// Then the external, versioned configuration is defaulted and converted to the internal type.
// Right thereafter, the configuration is defaulted again with dynamic values
// Lastly, the internal config is validated and returned.
func LoadOrDefaultUpgradeConfiguration(cfgPath string, defaultversionedcfg *kubeadmapiv1.UpgradeConfiguration, opts LoadOrDefaultConfigurationOptions) (*kubeadmapi.UpgradeConfiguration, error) { … }

// DefaultedUpgradeConfiguration takes a versioned UpgradeConfiguration (usually filled in by command line parameters), defaults it, converts it to internal and validates it
func DefaultedUpgradeConfiguration(defaultversionedcfg *kubeadmapiv1.UpgradeConfiguration, _ LoadOrDefaultConfigurationOptions) (*kubeadmapi.UpgradeConfiguration, error) { … }