yamlo

Documentation

Overview

Package yamlo allows the yamler package to unmarshal unexported types and finds yaml configuration files.

Index

• func AddYamlReferences(subPackageOptionData []pflags.OptionData, fieldPointerValues []interface{}) (optionDataList []pflags.OptionData)
• func ApplyYaml(program, yamlFile, yamlDictionaryKey string, doYaml bool, ...) (err error)
• func FindFile(filename, program string) (readFilename string, byts []byte, err error)
• type GenericYaml

Functions

func AddYamlReferences

func AddYamlReferences(
	subPackageOptionData []pflags.OptionData,
	fieldPointerValues []interface{},
) (optionDataList []pflags.OptionData)

AddYamlReferences returns a pflags.OptionData slice of options to main

• return value is appended to the pflags.OptionData list in main
• filedPointerValues is a list of references to main’s y YamlData
• subPackageOptionData is a list of options declared in subpackage

func ApplyYaml

func ApplyYaml(
	program, yamlFile, yamlDictionaryKey string, doYaml bool,
	genericYaml GenericYaml,
	optionData []pflags.OptionData,
) (err error)

ApplyYaml updates effective options with values read from a yaml file

• program is app name “date” used to construct yaml file name
• yamlFile is a specified file, or for empty string, a scan for files:
• — filename: [program]-[hostname].yaml [program].yaml
• — Directories: ~/apps .. /etc
• — if a specified file is missing, that is error
• — if no default file exists, or file was empty, no yaml options are loaded
• yamlDictionaryKey is the key read form the top-level dictionary in yaml, empty string is default “options:”
• genericYaml is a wrapper of unknown types
• optionData is the list of options, containing pointers to effective option values
• The top entry in the yaml file must be a dictionary
• The value for yamlDictionaryKey must be a dictionary
• the remainder of the yamlDictionaryKey is read when it matches the YamData struct
• -verbose=yamlo.ApplyYaml “github.com/haraldrudell/parl/yamlo.ApplyYaml”

func FindFile

func FindFile(filename, program string) (readFilename string, byts []byte, err error)

FindFile locates and reads the yaml file

• if filename is empty, try dirs: [~/app, .., /etc] files: [app-host.yaml, app.yaml]
• readFilename is absolute, cleaned filename

Types

type GenericYaml

type GenericYaml interface {
	// Unmarshal updates [yamlo.Unmarshaler]’s value pointer with
	// data from yaml
	//	- yamlText is utf8-encoded binary data read from the yaml file
	//	- yamlDictionaryKey is the name of the top-level dictionary-key
	//		typically “options”
	//	- hasData indicates that unmarshal succeeded and yamlDictionaryKey
	//		was present
	Unmarshal(yamlText []byte, yamlDictionaryKey string) (hasData bool, err error)
	// VisitedReferencesMap returns a map of
	// key: any-typed pointers to fields of u.y,
	// value: lower-case field names
	// - unmarshals yaml again to an any object and then
	// builds the visited references map by comparing the unmarshaled object to the
	// u.y struct-pointer
	VisitedReferencesMap(yamlText []byte, yamlDictionaryKey string) (yamlVisistedReferences map[any]string, err error)
	// YDump returns field names and values for the yaml value struct
	YDump() (yamlVPrint string)
}

GenericYaml is a wrapper for yamlo.Unmarshaler that allows the yamlo package to unmarshal yaml to an unimported type