GoFig

Easy config parsing for server applications.

Features

• generates flags (command line options) by parsing a structure
• supports optional config file lookup in different path (JSON, TOML and YAML files)
• supports optional config file flag (JSON, TOML and YAML files)
• supports environment variables
• supports user-defined default values

Types supported for flags and environment variables:

type	env	flag
string	✔	✔
bool	✔	✔
int	✔	✔
int64	✔	✔
uint	✔	✔
uint64	✔	✔
float64	✔	✔
gofig.Duration	✔	✔

Other types except for the list above such as float32 are not supported.

For the usage of gofig.Duration, please refer to ParseDuration

Order of priority

Each item takes precedence (override) over the item below it:

• flag
• env
• config
• default (user-defined value)

Struct tags

• json:
  • json: custom configuration key name (- to disable this json key)
• toml:
  • toml: custom configuration key name (- to disable this toml key)
• yaml:
  • yaml: custom configuration key name (- to disable this yaml key)
• env:
  • env: custom environment variable name (- to disable this env var)
• flag:
  • flag: custom flag name (- to disable this flag)
  • desc: flag description

Example

package main

import (
	"fmt"
	"time"

	"github.com/curvegrid/gofig"
)

type Config struct {
	Debug       bool           `flag:"d" desc:"enable debugging"`
	Environment string         `json:"env" toml:"env" yaml:"env" env:"env" flag:"e" desc:"environment name"`
	Port        int            `desc:"port to listen on"`
	Timeout     gofig.Duration `desc:"server timeout"`
}

func main() {
	cfg := Config{}
	cfg.Port = 5243 // user-defined default value
	cfg.Timeout = gofig.Duration(30 * time.Second)

	gofig.SetEnvPrefix("GF")
	gofig.SetConfigFileFlag("c", "config file")
	gofig.AddConfigFile("default") // gofig will try to load default.json, default.toml and default.yaml
	gofig.Parse(&cfg)

	fmt.Printf("Config: %+v\n", cfg)
}