atomaths / nutrition

Golang library for gathering configuration data from different sources

Nutrition

Package nutrition provides decoding of different sources based on user defined struct. Source is the stream of lines in 'key=value' form. Environment, file and raw io.Reader sources are supported. Package can decode types boolean, numeric, and string types as well as time.Duration and time.Time. The later could be customized with formats.

Documentation

The Nutrition API reference is available on GoDoc.

Installation

Install Nutrition using the go get command:

go get -u github.com/dmotylev/nutrition

Example

Feed struct from environment only:

// Try:
//
// APP_TIMEOUT=1h2m3s APP_DAY=2013-12-13 APP_NUMWORKERS=5 APP_WORKERNAME=Hulk go run p.go
//
package main

import (
	"fmt"
	"time"

	"github.com/dmotylev/nutrition"
)

func main() {
	var conf struct {
		Timeout    time.Duration
		Day        time.Time `time,format:"2006-01-02"`
		WorkerName string
		NumWorkers int
	}

	err := nutrition.Env("APP_").Feed(&conf)

	fmt.Printf("err=%v\n", err)
	fmt.Printf("timeout=%s\n", conf.Timeout)
	fmt.Printf("day=%s\n", conf.Day.Format(time.UnixDate))
	fmt.Printf("worker=%s\n", conf.WorkerName)
	fmt.Printf("workers=%d\n", conf.NumWorkers)
}

Feed struct from stdin only:

// Try:
//
// echo -e "timeout=1h2m3s\nday=2013-12-13\nnumWorkers=5\nworkerName=Hulk" | go run p.go
//
package main

import (
	"fmt"
	"time"
	"os"

	"github.com/dmotylev/nutrition"
)

func main() {
	var conf struct {
		Timeout    time.Duration
		Day        time.Time `time,format:"2006-01-02"`
		WorkerName string
		NumWorkers int
	}

	err := nutrition.Reader(os.Stdin).Feed(&conf)

	fmt.Printf("err=%v\n", err)
	fmt.Printf("timeout=%s\n", conf.Timeout)
	fmt.Printf("day=%s\n", conf.Day.Format(time.UnixDate))
	fmt.Printf("worker=%s\n", conf.WorkerName)
	fmt.Printf("workers=%d\n", conf.NumWorkers)
}

Feed struct from file only:

// Try:
//
// echo -e "timeout=1h2m3s\nday=2013-12-13\nnumWorkers=5\nworkerName=Hulk" > env && go run p.go
//
package main

import (
	"fmt"
	"time"

	"github.com/dmotylev/nutrition"
)

func main() {
	var conf struct {
		Timeout    time.Duration
		Day        time.Time `time,format:"2006-01-02"`
		WorkerName string
		NumWorkers int
	}

	err := nutrition.Reader("env").Feed(&conf)

	fmt.Printf("err=%v\n", err)
	fmt.Printf("timeout=%s\n", conf.Timeout)
	fmt.Printf("day=%s\n", conf.Day.Format(time.UnixDate))
	fmt.Printf("worker=%s\n", conf.WorkerName)
	fmt.Printf("workers=%d\n", conf.NumWorkers)
}

All together:

// Try:
//
// echo -e "timeout=1h2m3s\nday=2013-12-13\nnumWorkers=5\nworkerName=Hulk" > env && echo -e "numWorkers=10000\nworkerName=Fido" | APP_WORKERNAME=Pinnoccio go run p.go
//
package main

import (
	"fmt"
	"os"
	"time"

	"github.com/dmotylev/nutrition"
)

func main() {
	var conf struct {
		Timeout    time.Duration
		Day        time.Time `time,format:"2006-01-02"`
		WorkerName string
		NumWorkers int
	}

	// You can change the order. First source with value will be used
	err := nutrition.Env("APP_").Reader(os.Stdin).File("env").Feed(&conf)

	fmt.Printf("err=%v\n", err)
	fmt.Printf("timeout=%s\n", conf.Timeout)
	fmt.Printf("day=%s\n", conf.Day.Format(time.UnixDate))
	fmt.Printf("worker=%s\n", conf.WorkerName)
	fmt.Printf("workers=%d\n", conf.NumWorkers)
}

License

The package available under LICENSE.