Dropwizard-like configuration file parser

[Richard Crowley]

@mihasya's favorite thing about Dropwizard is the way configuration classes are declared and instantiated from YAML files. The flags package notwithstanding, Tiger Tonic should really have the same.

[Wade Simmons]

The example configuration loader from the Boundary's Comparing Go and Java blog post is pretty simple and perhaps a good start:

type Config struct {
  Db struct {
    Name     string
    User     string
    Password string
  }
}

func ReadConfig() Config {
  if len(os.Args) != 2 {
    log.Fatal("You must supply a configuration filename")
  }
  filename := os.Args[1]
  bytes, err := ioutil.ReadFile(filename)
  if err != nil {
    panic(err)
  }
  var c Config
  err = json.Unmarshal(bytes, &c)
  if err != nil {
    panic(err)
  }
  return c
}

[Richard Crowley]

It's impressive that you've read the entire Internet, @wadey.

And yes, that's an excellent start. I'd probably want to add support for non-zero default values by way of a tag.

[Richard Crowley]

@wadey @mihasya is this too stupid and simple? It's usefulness is, I bet, rather tied to per-request context in #27.

[Mikhail P]

I would prefer some sort of abstraction with a json impl that is easy enough to swap out for something like yml. Not sure you care :D I can try and come up with a way to do this if you'd like, not sure when I'll actually get to it

[Richard Crowley]

@mihasya How's this new change strike you?

[Mikhail P]

AYE! 🤘 ✊ 🚬