Confparse

Declarative command line argument parser for golang projects.

Install

Install go module

go get github.com/memclutter/confparse

Usage

Use struct tags to declare command-line arguments.

// ...

type Config struct {
	Argument1 string `name:"arg1" usage:"Argument 1 help text"`
	Timeout time.Duration `name:"timeout" value:"200ms" usage:"Timeout argument"`
}

// ...

Supported Types

Different types of arguments are supported:

string by default any arguments is a string
int like 1, 2, 300, -23 etc
time.Duration for time interval argument, like 10s, 500ms, 20us etc
bool for boolean argument

Environment Extension

Use special struct tag envVar if you application read configuration from environment variables. Set environment variable name in envVar and confparse read value from there.

Example

The following is an example of defining a configuration for a simple web server

package main

import (
	"log"
	"net/http"

	"github.com/memclutter/confparse"
)

type Config struct {
	Addr string `name:"addr" value:":8000" usage:"Listen and serve address"`
	ApiKey string `name:"apiKey" envVar:"API_KEY" usage:"API key"`
}

var appConfig = &Config{}

func main() {
	if err := confparse.Parse(appConfig); err != nil {
		log.Fatalf("Error parse configuration: %s", err)
	}

        log.Printf("API Key: %s", appConfig.ApiKey)

	log.Printf("Listen and serve on %s", appConfig.Addr)
	if err := http.ListenAndServe(appConfig.Addr, nil); err != nil {
		log.Fatalf("Listen and serve error: %s", err)
	}
}