ECO - Enviroment Configurations to Go Structs

This is a tiny package to map the environment variables to Go structs w/o the need of a config file. It supports prefixing, nesting and default values in your config structs. Please check out the examples below.

Supported Types

• string
• int, Uint, int8, Uint8, int16, Uint16, int32, Uint32, int64, Uint64
• float32, float64
• bool
• []string
• []int, []int64
• []float32, []float64

Installation

go get github.com/orkungursel/go-eco

Examples

Using Global API

package main

import (
	"fmt"

	"github.com/orkungursel/go-eco"
)

type Config struct {
	Port int    `env:"PORT" default:"8080"`
	Host string `env:"HOST" default:"localhost"`
}

func main() {
	config := Config{}

	if err := eco.Unmarshal(&config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}

$ PORT=8081 go run main.go

{Port:8081 Host:localhost}

Using Local Instance

...
	config := Config{}

	e := eco.New()
	e.SetPrefix("APP")

	if err := e.Unmarshal(&config); err != nil {
		panic(err)
	}
...

$ APP_PORT=8081 go run main.go

{Port:8081 Host:localhost}

Nested Structs

package main

import (
	"fmt"

	"github.com/orkungursel/go-eco"
)

type Config struct {
	Port int    `env:"PORT" default:"8080"`
	Host string `env:"HOST" default:"localhost"`
	Logger struct {
		Level string `env:"LEVEL" default:"info"`
	}
}

func main() {
	config := Config{}

	if err := eco.Unmarshal(&config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}

$ PORT=8081 LOGGER_LEVEL=debug go run main.go

{Port:8081 Host:localhost Logger: {Level:debug}}

API

SetPrefix

func SetPrefix(prefix string)

SetPrefix sets the prefix for the environment variables.

By default, the prefix is empty.

Example

...

func main() {
	config := Config{}

	if err := eco.SetPrefix("custom_prefix").Unmarshal(&config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}

$ CUSTOM_PREFIX_PORT=8081 go run main.go

{Port:8081 Host:localhost}

SetArraySeparator

func SetArraySeparator(sep string)

SetArraySeparator sets the separator for array values.

By default, the separator is `,`.

Example

package main

import (
	"fmt"

	"github.com/orkungursel/go-eco"
)

type Config struct {
    Foo []string `default:"foo,bar,baz"`
}

func main() {
	config := Config{}

	if err := eco.SetArraySeparator(",").Unmarshal(&config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}

SetEnvNameSeparator

func SetEnvNameSeparator(envNameSeparator string) *eco {

SetEnvNameSeparator sets the separator for the environment variable names.

By default, the separator is `_`.

Example

package main

import (
	"fmt"

	"github.com/orkungursel/go-eco"
)

type Config struct {
	Sub struct {
		Foo string
	}
}

func main() {
	config := Config{}

	if err := eco.SetEnvNameSeparator("__").Unmarshal(&config); err != nil {
		panic(err)
	}

	fmt.Printf("%+v\n", config)
}

$ SUB__FOO=bar go run main.go

{Sub: {Foo:bar}}

Unmarshal

func Unmarshal(v interface{}) error

Unmarshal takes a pointer to a struct and unmarshals the environment variables to the struct.

License

This project is licensed under the MIT License.