goconfig

README

Goconfig is an extremely simple and powerful configuration library for your Go programs that read values from environment vars, command line arguments and configuration file in JSON.

Make your configuration flags compact and easy to read.

Arguments are parsed from command line with the standard flag library.

• How to use
• Supported types
• Builtin flags
  • -help
  • -config
• Contribute
• Testing
• Example project

How to use

Define your structure with descriptions:

type myconfig struct {
	Name      string `usage:"The name of something"`
	EnableLog bool   `usage:"Enable logging into logdb" json:"enable_log"`
	MaxProcs  int    `usage:"Maximum number of procs"`
	UsersDB   db
	LogDB     db
}

type db struct {
	Host string `usage:"Host where db is located"`
	User string `usage:"Database user"`
	Pass string `usage:"Database password"`
}

Instance your config with default values:

c := &myconfig{
	EnableLog: true,
	UsersDB: db{
		Host: "localhost",
		User: "root",
		Pass: "123456",
	},
}

Fill your config:

goconfig.Read(c)

How the -help looks like:

Usage of example:
  -enablelog
    	Enable logging into logdb (default true)
  -logdb.host string
    	Host where db is located (default "localhost")
  -logdb.pass string
    	Database password (default "123456")
  -logdb.user string
    	Database user (default "root")
  -maxprocs int
    	Maximum number of procs
  -name string
    	The name of something
  -usersdb.host string
    	Host where db is located
  -usersdb.pass string
    	Database password
  -usersdb.user string
    	Database user

Supported types

Mainly almost all types from flag library are supported:

• bool
• float64
• int64
• int
• string
• uint64
• uint
• struct (hyerarchical keys)
• array (any type)

For the moment duration type is not supported.

Builtin flags

-help

Since flag library is using the key -help to show usage, Goconf is behaving in the same way.

-config

Builtin flag -config allow read configuration from a file. For the example configuration above, this is a sample config.json file:

{
  "name": "Fulanito",
  "usersdb": {
    "host": "localhost",
    "user": "admin",
    "pass": "123"
  }
}

Configuration precedence is as follows (higher to lower):

• Arg command line
• Json config file
• Environment variable
• Default value

Contribute

Feel free to fork, make changes and pull-request to master branch.

If you prefer, create a new issue or email me for new features, issues or whatever.

Testing

This command will pass all tests.

make

Example project

This project includes a sample project with a sample configuration. To make the binary:

make example

Documentation

Index

• func FillArgs(c interface{}, args []string) error
• func FillEnvironments(c interface{}) (err error)
• func FillJson(c interface{}, filename string) error
• func Read(c interface{})

Functions

func FillArgs

func FillArgs(c interface{}, args []string) error

func FillEnvironments

func FillEnvironments(c interface{}) (err error)

func FillJson

func FillJson(c interface{}, filename string) error

func Read

func Read(c interface{})