add BytesToXConfiguration function

cmd/kubeadm/app/util/config/initconfiguration.go

@@ -291,10 +291,11 @@ func LoadOrDefaultInitConfiguration(cfgPath string, versionedInitCfg *kubeadmapi
 }
 
 // BytesToInitConfiguration converts a byte slice to an internal, defaulted and validated InitConfiguration object.
-// The map may contain many different YAML/JSON documents. These YAML/JSON documents are parsed one-by-one
+// The map may contain many different YAML/JSON documents. These documents are parsed one-by-one
 // and well-known ComponentConfig GroupVersionKinds are stored inside of the internal InitConfiguration struct.
 // The resulting InitConfiguration is then dynamically defaulted and validated prior to return.
 func BytesToInitConfiguration(b []byte, skipCRIDetect bool) (*kubeadmapi.InitConfiguration, error) {
+	// Split the YAML/JSON documents in the file into a DocumentMap
 	gvkmap, err := kubeadmutil.SplitConfigDocuments(b)
 	if err != nil {
 		return nil, err

cmd/kubeadm/app/util/config/joinconfiguration.go

@@ -87,6 +87,14 @@ func LoadJoinConfigurationFromFile(cfgPath string, opts LoadOrDefaultConfigurati
 		return nil, errors.Wrapf(err, "unable to read config from %q ", cfgPath)
 	}
 
+	return BytesToJoinConfiguration(b, opts)
+}
+
+// BytesToJoinConfiguration converts a byte slice to an internal, defaulted and validated JoinConfiguration object.
+// The map may contain many different YAML/JSON documents. These documents are parsed one-by-one.
+// The resulting JoinConfiguration is then dynamically defaulted and validated prior to return.
+func BytesToJoinConfiguration(b []byte, opts LoadOrDefaultConfigurationOptions) (*kubeadmapi.JoinConfiguration, error) {
+	// Split the YAML/JSON documents in the file into a DocumentMap
 	gvkmap, err := kubeadmutil.SplitConfigDocuments(b)
 	if err != nil {
 		return nil, err

cmd/kubeadm/app/util/config/resetconfiguration.go

@@ -91,6 +91,14 @@ func LoadResetConfigurationFromFile(cfgPath string, opts LoadOrDefaultConfigurat
 		return nil, errors.Wrapf(err, "unable to read config from %q ", cfgPath)
 	}
 
+	return BytesToResetConfiguration(b, opts)
+}
+
+// BytesToResetConfiguration converts a byte slice to an internal, defaulted and validated ResetConfiguration object.
+// The map may contain many different YAML/JSON documents. These documents are parsed one-by-one.
+// The resulting ResetConfiguration is then dynamically defaulted and validated prior to return.
+func BytesToResetConfiguration(b []byte, opts LoadOrDefaultConfigurationOptions) (*kubeadmapi.ResetConfiguration, error) {
+	// Split the YAML/JSON documents in the file into a DocumentMap
 	gvkmap, err := kubeadmutil.SplitConfigDocuments(b)
 	if err != nil {
 		return nil, err

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

@@ -93,22 +93,29 @@ func LoadUpgradeConfigurationFromFile(cfgPath string, _ LoadOrDefaultConfigurati
 		return nil, errors.Wrapf(err, "unable to load config from file %q", cfgPath)
 	}
 
-	// Split the YAML/JSON documents in the file into a DocumentMap
-	docmap, err := kubeadmutil.SplitConfigDocuments(configBytes)
-	if err != nil {
-		return nil, err
-	}
-
 	// Convert documentMap to internal UpgradeConfiguration, InitConfiguration and ClusterConfiguration from config file will be ignored.
 	// Upgrade should respect the cluster configuration from the existing cluster, re-configure the cluster with a InitConfiguration and
 	// ClusterConfiguration from the config file is not allowed for upgrade.
-	if upgradeCfg, err = DocMapToUpgradeConfiguration(docmap); err != nil {
+	if upgradeCfg, err = BytesToUpgradeConfiguration(configBytes); err != nil {
 		return nil, err
 	}
 
 	return upgradeCfg, nil
 }
 
+// BytesToUpgradeConfiguration converts a byte slice to an internal, defaulted and validated UpgradeConfiguration object.
+// The map may contain many different YAML/JSON documents. These documents are parsed one-by-one.
+// The resulting UpgradeConfiguration is then dynamically defaulted and validated prior to return.
+func BytesToUpgradeConfiguration(b []byte) (*kubeadmapi.UpgradeConfiguration, error) {
+	// Split the YAML/JSON documents in the file into a DocumentMap
+	gvkmap, err := kubeadmutil.SplitConfigDocuments(b)
+	if err != nil {
+		return nil, err
+	}
+
+	return documentMapToUpgradeConfiguration(gvkmap, false)
+}
+
 // 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.