config

README

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Simple and idiomatic parsing of configuration files and environment variables.

Installation

$ go get github.com/hapci/go-config

Getting started

Unmarshal files

example.yml

string: "text"
map:
  key1:
    array: [ "item10", "item20", "item30" ]
    int: 40
    float: 50.6
    bool: true

code:

package main

import (
	"fmt"

	"github.com/hapci/go-config"
)

func main() {
	cfg := struct {
		String string `mapstructure:"string"`
		Map    map[string]struct {
			Array []string `mapstructure:"array"`
			Int   int      `mapstructure:"int"`
			Float float64  `mapstructure:"float"`
			Bool  bool     `mapstructure:"bool"`
		} `mapstructure:"map"`
	}{}

	err := config.UnmarshalFromFile("example.yml", &cfg)
	if err != nil {
		fmt.Println(err)
	}
}

Supported formats: JSON, TOML, YAML, HCL, INI, envfile and Java properties.

Unmarshal environment variables

package main

import (
	"fmt"
	"os"

	"github.com/hapci/go-config"
)

func main() {
	err := os.Setenv("int", "1")
	if err != nil {
		fmt.Println(err)
	}

	err = os.Setenv("string", "text")
	if err != nil {
		fmt.Println(err)
	}

	err = os.Setenv("BOOL", "true")
	if err != nil {
		fmt.Println(err)
	}

	cfg := struct {
		Int    int     `env:"int"`
		String string  `env:"string,required=true"`
		Float  float64 `env:"float,default=3.14"`
		Bool   bool    `env:"bool,BOOL"`
	}{}

	err = config.UnmarshalFromEnv(&cfg)
	if err != nil {
		fmt.Println(err)
	}
}

Documentation

Index

• func UnmarshalFromEnv(v interface{}) error
• func UnmarshalFromFile(filename string, v interface{}) error

Examples

• UnmarshalFromEnv
• UnmarshalFromFile

Functions

func UnmarshalFromEnv

func UnmarshalFromEnv(v interface{}) error

UnmarshalFromEnv parses the environment variables and stores the results in the value pointed to by v. If v is nil or not a pointer to a struct, UnmarshalFromEnv returns an env.ErrInvalidValue.

Fields tagged with "env" will have the unmarshalled env value of the matching key. If the tagged field is not exported, UnmarshalFromEnv returns env.ErrUnexportedField.

If the field has a type that is unsupported, UnmarshalFromEnv returns env.ErrUnsupportedType.

Example

err := os.Setenv("int", "1")
if err != nil {
	fmt.Println(err)
}

err = os.Setenv("string", "text")
if err != nil {
	fmt.Println(err)
}

err = os.Setenv("BOOL", "true")
if err != nil {
	fmt.Println(err)
}

cfg := struct {
	Int    int     `env:"int"`
	String string  `env:"string,required=true"`
	Float  float64 `env:"float,default=3.14"`
	Bool   bool    `env:"bool,BOOL"`
}{}

err = config.UnmarshalFromEnv(&cfg)
if err != nil {
	fmt.Println(err)
}

func UnmarshalFromFile

func UnmarshalFromFile(filename string, v interface{}) error

UnmarshalFromFile decodes the file and assigns the decoded values into the out value.

Fields tagged with "mapstructure" will have the unmarshalled value of the matching key.

Example

cfg := struct {
	String string `mapstructure:"string"`
	Map    map[string]struct {
		Array []string `mapstructure:"array"`
		Int   int      `mapstructure:"int"`
		Float float64  `mapstructure:"float"`
		Bool  bool     `mapstructure:"bool"`
	} `mapstructure:"map"`
}{}

err := config.UnmarshalFromFile("filename.yml", &cfg)
if err != nil {
	fmt.Println(err)
}