envconfig

import "github.com/kelseyhightower/envconfig"

Documentation

See godoc

Usage

Set some environment variables:

export MYAPP_DEBUG=false
export MYAPP_PORT=8080
export MYAPP_USER=Kelsey
export MYAPP_RATE="0.5"

Write some code:

package main

import (
    "fmt"
    "log"

    "github.com/kelseyhightower/envconfig"
)

type Specification struct {
    Debug bool
    Port  int
    User  string
    Rate  float32
}

func main() {
    var s Specification
    err := envconfig.Process("myapp", &s)
    if err != nil {
        log.Fatal(err.Error())
    }
    format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\n"
    _, err = fmt.Printf(format, s.Debug, s.Port, s.User, s.Rate)
    if err != nil {
        log.Fatal(err.Error())
    }
}

Results:

Debug: false
Port: 8080
User: Kelsey
Rate: 0.500000