configuration managed by the application

Application.scala

object Application{
  def main(args: Array[String]): Unit = {
    val config = Config.get( args(0) )
    val db = connectToDb( config.dbHost, config.dbPort )
    ...
  }
}

object Config{
  def get(config: String) = {
    config match {
      case "test" => Config("db.test-server.com",10000)
      case "production" => Config("db.production-server.com",12345)
      case _ => throw new Exception("unknown config: "+config)
    }
  }
}

case class Config(
  dbHost: String,
  port: Int
)