ENV File Resolver for kong

This tiny package adds ENV-files loader to the kong CLI parser.

Usage

The easiest way to add ENV-file support to the app is the following.

# ./.env
VAR_STRING="Any value here"

// ./main.go

package main

import (
	"fmt"

	"github.com/alecthomas/kong"

	kongdotenv "github.com/titusjaka/kong-dotenv-go"
)

type CLI struct {
	EnvFile kongdotenv.ENVFileConfig `kong:"optional,default='.env',name=env-file"`

	EnvVarString string `kong:"optional,name=var-string,env=VAR_STRING"`
}

func (c CLI) Run() error {
	fmt.Printf(`Env File: %s; Env Var String: %s.`, c.EnvFile, c.EnvVarString,
	)

	return nil
}

func main() {
	var cli CLI

	kCtx := kong.Parse(&cli)
	kCtx.FatalIfErrorf(kCtx.Run())
}

go run ./main.go --env-file=./.env

# Output: Env File: .env; Env Var String: Any value here.

Limits

The package has the following limitations:

• Values are applied only to variables with an env tag.
• ENV variables have higher priority than ENV-file ones. Therefore, if you have an ENV set, the same variable in the ENV file will be ignored.

Examples

• example with minimum configuration: ./examples/config_type;
• obsolete example with kong.ConfigurationLoader resolver: ./examples/resolver.