nxs-go-conf

This Go package provides a simple way to handle configuration parameters for Go programs.

Features

• Manage options in structure field tags
  To describe configuration file structure you simply need to define the struct in the Go program code. In that struct you can use field tags to set different options and to determine config file decoding behavior. Currently, the next tags are available:

  • conf: defines custom name for an option
  • conf_extraopts: provides advanced settings for option. This tag may have the following values:
    • required: option with this tag is mandatory. If it is set, but corresponding option is not defined in the config file, it will cause an error.
    • default: determines default value for the option.

• ENV variables as option values
  You may specify the option value as ENV:VARIABLE_NAME. It will use the value of the relative environment variable (i.e. VARIABLE_NAME) as value for that option.

• YAML and JSON formats are available
  Currently, you can use config files in YAML or JSON formats. To switch the format you only need to specify the appropriate setting for config file load function.

• Catch the unknown options
  You can catch options, that are contained in config file but has no matching in the result interface.

Install

go get github.com/nixys/nxs-go-conf

Example of usage

You may find more examples in unit-tests in this repository

Parse simple config file:

package main

import (
        "fmt"

        "github.com/nixys/nxs-go-conf"
)

const (
        confPath = "./main.conf"
)

type confOpts struct {
        Name string `conf:"name" conf_extraopts:"required"`
        Age  int    `conf_extraopts:"default=19"`
        Job  struct {
                Name    string  `conf:"name" conf_extraopts:"required"`
                Address string  `conf:"address" conf_extraopts:"default=Some Address"`
                Salary  float64 `conf:"salary" conf_extraopts:"default=1.3"`
        } `conf:"job" conf_extraopts:"required"`
        FavoriteDishes []string `conf:"favorite_dishes"`
}

func main() {

        var c confOpts

        if err := conf.Load(&c, conf.Settings{
                ConfPath:    confPath,
                ConfType:    conf.ConfigTypeYAML,
                UnknownDeny: true,
        }); err != nil {
                fmt.Println(err)
                return
        }

        fmt.Printf("%+v\n", c)
}

Relative config file:

name: John Doe
job:
  name: ENV:CONF_JOB_NAME
  salary: ENV:CONF_JOB_SALARY
favorite_dishes:
- apples
- ice cream

Run:

CONF_JOB_NAME="Best job" CONF_JOB_SALARY="1.0" go run main.go

Feedback

For support and feedback please contact me:

• telegram: @borisershov
• e-mail: b.ershov@nixys.ru

License

nxs-go-conf is released under the MIT License.