shrty/config.go

package main

import (
  "flag"
  "github.com/caarlos0/env"
  "os"
  "path"
)

func DefaultConfig() Config {
  c := Config{
    RootPath: "./",
    APIkey: "thisIsNotASecretTokenNow",
    Host:   "localhost",
    Port:   "6889",
    Title:  "Shrty",
  }
  c.DB = c.RootPath + "shrty.db"
  return c
}

type Config struct {
  RootPath string `env:"SHRTY_ROOT_PATH"`
  DB       string `env:"SHRTY_DB_FILE"`
  APIkey   string `env:"SHRTY_API_KEY"`
  Host     string `env:"SHRTY_HOST"`
  Port     string `env:"SHRTY_PORT"`
  Domain   string `env:"SHRTY_DOMAIN"`
  Title    string `env:"SHRTY_TITLE"`
  CheckDomain bool `env:"SHRTY_CHECK_DOMAIN"`
}

func (c Config) HostPort() string {
  return c.Host + ":" + c.Port
}

func ReadConfig() *Config {
  c, err := readConfig(flag.NewFlagSet(os.Args[0], flag.ExitOnError), os.Args[1:])
  if err != nil {
    // sould never happen, because of flag default policy ExitOnError
    panic(err)
  }
  return c
}

func readConfig(f *flag.FlagSet, args []string) (*Config, error){
  config := DefaultConfig()

  // Environment variables
  err := env.Parse(&config)
  if err != nil {
    return nil, err
  }

  // Setting Rootpath from flag or enviorment and set the db path to new root.
  f.StringVar(&config.RootPath, "root", config.RootPath, "The path to the shrty root directory.")
  f.StringVar(&config.DB, "db-file", config.DB, "The db file to use")
  if config.DB == "./shrty.db" && config.RootPath != "./" {
    config.DB = path.Join(config.RootPath, "shrty.db")
  }

  // Setting up all the other flags
  f.StringVar(&config.Host, "host", config.Host, "The host to listen on")
  f.StringVar(&config.Port, "port", config.Port, "The port to listen on")
  f.StringVar(&config.APIkey, "apikey", config.APIkey, "The Key to connect to the API")
  f.StringVar(&config.Domain, "domain", config.Domain, "The domain for redirect links")
  f.StringVar(&config.Title, "title", config.Title, "The title on the Front")

  // Arguments variables
  err = f.Parse(args)
  if err != nil {
    return nil, err
  }

  return &config, err
}