How to handle configuration in Go [closed]

Question

I'm new at Go programming, and I'm wondering: what is the preferred way to handle configuration parameters for a Go program (the kind of stuff one might use properties files or ini files for, in other contexts)?

Answer 1

The JSON format worked for me quite well. The standard library offers methods to write the data structure indented, so it is quite readable.

See also this golang-nuts thread.

The benefits of JSON are that it is fairly simple to parse and human readable/editable while offering semantics for lists and mappings (which can become quite handy), which is not the case with many ini-type config parsers.

Example usage:

conf.json:

{     "Users": ["UserA","UserB"],     "Groups": ["GroupA"] } 

Program to read the configuration

import (     "encoding/json"     "os"     "fmt" )  type Configuration struct {     Users    []string     Groups   []string }  file, _ := os.Open("conf.json") defer file.Close() decoder := json.NewDecoder(file) configuration := Configuration{} err := decoder.Decode(&configuration) if err != nil {   fmt.Println("error:", err) } fmt.Println(configuration.Users) // output: [UserA, UserB] 

Answer 2

Another option is to use TOML, which is an INI-like format created by Tom Preston-Werner. I built a Go parser for it that is extensively tested. You can use it like other options proposed here. For example, if you have this TOML data in something.toml

Age = 198 Cats = [ "Cauchy", "Plato" ] Pi = 3.14 Perfection = [ 6, 28, 496, 8128 ] DOB = 1987-07-05T05:45:00Z 

Then you can load it into your Go program with something like

type Config struct {     Age int     Cats []string     Pi float64     Perfection []int     DOB time.Time }  var conf Config if _, err := toml.DecodeFile("something.toml", &conf); err != nil {     // handle error }