How to handle configuration in Go

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]