goconfig

README

goconfig

goconfig uses a struct as input and populates the fields of this struct with parameters from command line, environment variables and configuration file.

Install

go get github.com/crgimenes/goconfig

Example

package main

import "github.com/crgimenes/goconfig"

/*
step 1: Declare your configuration struct,
it may or may not contain substructures.
*/

type mongoDB struct {
	Host string `cfgDefault:"example.com" cfgRequired:"true"`
	Port int    `cfgDefault:"999"`
}

type configTest struct {
	Domain    string
	DebugMode bool `json:"db" cfg:"db" cfgDefault:"false"`
	MongoDB   mongoDB
	IgnoreMe  string `cfg:"-"`
}

func main() {

	// step 2: Instantiate your structure.
	config := configTest{}

	// step 3: Pass the instance pointer to the parser
	err := goconfig.Parse(&config)
	if err != nil {
		println(err)
		return
	}

	/*
	   The parser populated your struct with the data
	   it took from environment variables and command
	   line and now you can use it.
	*/

	println("config.Domain......:", config.Domain)
	println("config.DebugMode...:", config.DebugMode)
	println("config.MongoDB.Host:", config.MongoDB.Host)
	println("config.MongoDB.Port:", config.MongoDB.Port)
}

With the example above try environment variables like $DOMAIN or $MONGODB_HOST and run the example again to see what happens.

You can also try using parameters on the command line, try -h to see the help.

Contributing

• Fork the repo on GitHub
• Clone the project to your own machine
• Create a branch with your modifications git checkout -b fantastic-feature.
• Then commit your changes git commit -m 'Implementation of new fantastic feature'
• Make a push to your branch git push origin fantastic-feature.
• Submit a Pull Request so that we can review your changes

Documentation

Overview

Package goconfig uses a struct as input and populates the fields of this struct with parameters fom command line, environment variables and configuration file.

Index

• Variables
• func DefaultUsage()
• func Parse(config interface{}) (err error)
• func PrintDefaults()
• type Fileformat

Examples

• Parse

Variables

var ErrFileFormatNotDefined = errors.New("file format not defined")

ErrFileFormatNotDefined Is the error that is returned when there is no defined configuration file format.

var File string

File name of default config file

var FileRequired bool

FileRequired config file required

var Formats []Fileformat

Formats is the list of registered formats.

var HelpString string

HelpString temporarily saves help

var Path string

Path sets default config path

var PrefixEnv string

PrefixEnv is a string that would be placed at the beginning of the generated Event tags.

var PrefixFlag string

PrefixFlag is a string that would be placed at the beginning of the generated Flag tags.

var Tag = "cfg"

Tag to set main name of field

var TagDefault = "cfgDefault"

TagDefault to set default value

var TagHelper = "cfgHelper"

TagHelper to set usage help line

var Usage func()

Usage is a function to show the help, can be replaced by your own version.

Functions

func DefaultUsage

func DefaultUsage()

DefaultUsage is assigned for Usage function by default

func Parse

func Parse(config interface{}) (err error)

Parse configuration

Example

type config struct {
	Name  string `cfg:"Name" cfgDefault:"root"`
	Value int    `cfg:"Value" cfgDefault:"123"`
}

cfg := config{}

err := Parse(&cfg)
if err != nil {
	println(err)
}

println("Name:", cfg.Name, "Value:", cfg.Value)

func PrintDefaults

func PrintDefaults()

PrintDefaults print the default help

Types

type Fileformat

type Fileformat struct {
	Extension   string
	Load        func(config interface{}) (err error)
	PrepareHelp func(config interface{}) (help string, err error)
}

Fileformat struct holds the functions to Load the file containing the settings