config.go

package main

import (
	"errors"
	"os"
	"reflect"
	"strconv"

	"github.com/BurntSushi/toml"
)

type dbBackendEnum uint8

const (
	// DBEnumMongo reporesents mongodb backend
	DBEnumMongo dbBackendEnum = iota
)

var dcfg DaemonConfig

func (b *dbBackendEnum) UnmarshalText(text []byte) error {
	s := string(text)
	switch s {
	case `mongo`, `mongodb`:
		*b = DBEnumMongo
	default:
		return errors.New("Invalid value to database backend")
	}
	return nil
}

// A DaemonConfig represents configurations for tunasccount daemon
type DaemonConfig struct {
	ReadOnly bool           `toml:"read_only"`
	DB       DatabaseConfig `toml:"database"`
	LDAP     LDAPConfig     `toml:"ldap"`
	HTTP     HTTPConfig     `toml:"http"`
	TUNA     TUNAConfig     `toml:"tunaccount"`
}

// A DatabaseConfig is the database config for tunaccount daemon
type DatabaseConfig struct {
	Backend  dbBackendEnum     `toml:"backend"`
	Addr     string            `toml:"addr" default:"127.0.0.1"`
	Port     int               `toml:"port" default:"27017"`
	Addrs    []string          `toml:"addrs"` // addr and port can be overrided by addrs
	Name     string            `toml:"name" default:"tunaccount"`
	User     string            `toml:"user"`
	Password string            `toml:"password"`
	Options  map[string]string `toml:"options"` // database specific options
}

// An LDAPConfig is ldap server configs
type LDAPConfig struct {
	ListenAddr string `toml:"listen_addr" default:"127.0.0.1"`
	ListenPort int    `toml:"listen_port" default:"389"`
	Suffix     string `toml:"suffix"` // o=tuna
}

// An HTTPConfig is http server configs
type HTTPConfig struct {
	ListenAddr string `toml:"listen_addr" default:"127.0.0.1"`
	ListenPort int    `toml:"listen_port" default:"9501"`
	SecretKey  string `toml:"secret_key"`
}

// A TUNAConfig specifies application level configs
type TUNAConfig struct {
	MinimumUID int `toml:"minimum_uid" default:"2000"`
	MinimumGID int `toml:"minimum_gid" default:"2000"`
	DefaultGID int `toml:"default_gid" default:"2000"`
}

// A ClientConfig specifies configurations for tunaccount cli client
type ClientConfig struct {
	ServerURL string `toml:"server_url"`
}

func setDefaultValues(v reflect.Value) {
	for i := 0; i < v.NumField(); i++ {
		vf := v.Field(i)
		if vf.Kind() == reflect.Struct {
			setDefaultValues(vf)
			continue
		}

		dv := v.Type().Field(i).Tag.Get("default")
		if dv != "" && vf.CanSet() {
			switch vf.Kind() {
			case reflect.String:
				vf.SetString(dv)
			case reflect.Int:
				iv, _ := strconv.Atoi(dv)
				vf.SetInt(int64(iv))
			}
		}
	}
}

func loadDaemonConfig(cfgFile string) (*DaemonConfig, error) {
	setDefaultValues(reflect.ValueOf(&dcfg).Elem())

	if _, err := os.Stat(cfgFile); err == nil {
		if _, err := toml.DecodeFile(cfgFile, &dcfg); err != nil {
			logger.Errorf("Error parsing config file: %s", err.Error())
			return nil, err
		}
	}

	return &dcfg, nil
}