api/internal/config/config.go

package config

import (
	"encoding/json"
	"errors"
	"log"
	"os"
	"strings"
	"sync"

	"gopkg.in/yaml.v2"
)

var globalMutex sync.Mutex
var global *Config

// Config is configuration data
type Config struct {
	Space    Space    `json:"space" yaml:"space"`
	Database Database `json:"database" yaml:"database"`
	Wiki     Wiki     `json:"wiki" yaml:"wiki"`
}

// Space is configuration for spaces.
type Space struct {
	Enabled   bool   `json:"enabled" yaml:"enabled"`
	Host      string `json:"host" yaml:"host"`
	AccessKey string `json:"accessKey" yaml:"accessKey"`
	SecretKey string `json:"secretKey" yaml:"secretKey"`
	Bucket    string `json:"bucket" yaml:"bucket"`
	MaxSize   int64  `json:"maxSize" yaml:"maxSize"`
	Root      string `json:"root" yaml:"root"`
	URLRoot   string `json:"urlRoot" yaml:"urlRoot"`
}

// Database is configuration for spaces.
type Database struct {
	Driver    string `json:"driver" yaml:"driver"`
	Host      string `json:"host" yaml:"host"`
	Port      int    `json:"port" yaml:"port"`
	Db        string `json:"db" yaml:"db"`
	Username  string `json:"username" yaml:"username"`
	Password  string `json:"password" yaml:"password"`
	Mechanism string `json:"mechanism" yaml:"mechanism"`
}

// Wiki is the wiki stuff.
type Wiki struct {
	URL string `json:"url" yaml:"url"`
}

// Load loads config stuff
func (config *Config) Load(filename string) error {
	log.Println("Trying to load config from " + filename)

	stat, err := os.Stat(filename)
	if err != nil {
		return err
	}

	if stat.Size() < 1 {
		return errors.New("File is empty")
	}

	file, err := os.Open(filename)
	if err != nil {
		return err
	}

	if strings.HasSuffix(filename, ".json") {
		return json.NewDecoder(file).Decode(config)
	}

	return yaml.NewDecoder(file).Decode(config)
}

// LoadAny loads the first of these files it can find
func (config *Config) LoadAny(filenames ...string) error {
	for _, filename := range filenames {
		if err := config.Load(filename); err != nil {
			continue
		}

		return nil
	}

	return errors.New("Failed to load configuration files")
}

// Global gets the global configuration, loading it if this is the first caller
func Global() Config {
	globalMutex.Lock()
	if global == nil {
		global = &Config{}
		err := global.LoadAny("/etc/aiterp/rpdata.yaml", "/etc/aiterp/rpdata.json", "./config.yaml", "./config.json")
		if err != nil {
			log.Fatalln(err)
		}
	}
	globalMutex.Unlock()

	return *global
}