Use Viper for Configuration

cmd/filemanager/main.go

@@ -1,68 +1,93 @@
 package main
 
 import (
-	"encoding/json"
-	"flag"
 	"fmt"
 	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
 	"os"
-	"strconv"
+	"path/filepath"
 	"strings"
 
 	lumberjack "gopkg.in/natefinch/lumberjack.v2"
 
 	"github.com/hacdias/filemanager"
 	"github.com/hacdias/fileutils"
+	flag "github.com/spf13/pflag"
+	"github.com/spf13/viper"
 )
 
-// confFile contains the configuration file for this File Manager instance.
-// If the user chooses to use a configuration file, the flags will be ignored.
-type confFile struct {
-	Database      string   `json:"database"`
-	Scope         string   `json:"scope"`
-	Address       string   `json:"address"`
-	Commands      []string `json:"commands"`
-	Port          int      `json:"port"`
-	Logger        string   `json:"log"`
-	AllowCommands bool     `json:"allowCommands"`
-	AllowEdit     bool     `json:"allowEdit"`
-	AllowNew      bool     `json:"allowNew"`
-}
-
 var (
 	addr          string
 	config        string
 	database      string
 	scope         string
 	commands      string
-	port          string
 	logfile       string
+	port          int
 	allowCommands bool
 	allowEdit     bool
 	allowNew      bool
 )
 
 func init() {
-	flag.StringVar(&config, "config", "", "JSON configuration file")
-	flag.StringVar(&port, "port", "0", "HTTP Port (default is random)")
-	flag.StringVar(&addr, "address", "", "Address to listen to (default is all of them)")
-	flag.StringVar(&database, "database", "./filemanager.db", "Database path")
-	flag.StringVar(&scope, "scope", ".", "Default scope for new users")
-	flag.StringVar(&commands, "commands", "git svn hg", "Space separated commands available for new users")
-	flag.StringVar(&logfile, "log", "stdout", "Logger to log the errors.")
-	flag.BoolVar(&allowCommands, "allow-commands", true, "Default allow commands option")
-	flag.BoolVar(&allowEdit, "allow-edit", true, "Default allow edit option")
-	flag.BoolVar(&allowNew, "allow-new", true, "Default allow new option")
+	flag.StringVarP(&config, "config", "c", "", "JSON configuration file")
+	flag.IntVarP(&port, "port", "p", 0, "HTTP Port (default is random)")
+	flag.StringVarP(&addr, "address", "a", "", "Address to listen to (default is all of them)")
+	flag.StringVarP(&database, "database", "d", "./filemanager.db", "Database file")
+	flag.StringVarP(&logfile, "log", "l", "stdout", "Errors logger; can use 'stdout', 'stderr' or file")
+	flag.StringVarP(&scope, "scope", "s", ".", "Default scope option for new users")
+	flag.StringVar(&commands, "commands", "git svn hg", "Default commands option for new users")
+	flag.BoolVar(&allowCommands, "allow-commands", true, "Default allow commands option for new users")
+	flag.BoolVar(&allowEdit, "allow-edit", true, "Default allow edit option for new users")
+	flag.BoolVar(&allowNew, "allow-new", true, "Default allow new option for new users")
+}
+
+func setupViper() {
+	viper.SetDefault("Address", "")
+	viper.SetDefault("Port", "0")
+	viper.SetDefault("Database", "./filemanager.db")
+	viper.SetDefault("Scope", ".")
+	viper.SetDefault("Logger", "stdout")
+	viper.SetDefault("Commands", []string{"git", "svn", "hg"})
+	viper.SetDefault("AllowCommmands", true)
+	viper.SetDefault("AllowEdit", true)
+	viper.SetDefault("AllowNew", true)
+
+	viper.BindPFlag("Port", flag.Lookup("port"))
+	viper.BindPFlag("Address", flag.Lookup("address"))
+	viper.BindPFlag("Database", flag.Lookup("database"))
+	viper.BindPFlag("Scope", flag.Lookup("scope"))
+	viper.BindPFlag("Logger", flag.Lookup("log"))
+	viper.BindPFlag("Commands", flag.Lookup("commands"))
+	viper.BindPFlag("AllowCommands", flag.Lookup("allow-commands"))
+	viper.BindPFlag("AllowEdit", flag.Lookup("allow-edit"))
+	viper.BindPFlag("AlowNew", flag.Lookup("allow-new"))
+
+	viper.SetConfigName("filemanager")
+	viper.AddConfigPath(".")
 }
 
 func main() {
+	setupViper()
 	flag.Parse()
 
-	// Set up process log before anything bad happens
-	switch logfile {
+	// Add a configuration file if set.
+	if config != "" {
+		viper.SetConfigName(strings.TrimSuffix(config, filepath.Ext(config)))
+	}
+
+	// Read configuration from a file if exists.
+	err := viper.ReadInConfig()
+	if err != nil {
+		if _, ok := err.(viper.ConfigParseError); ok {
+			panic(err)
+		}
+	}
+
+	// Set up process log before anything bad happens.
+	switch viper.GetString("Logger") {
 	case "stdout":
 		log.SetOutput(os.Stdout)
 	case "stderr":
@@ -78,57 +103,33 @@ func main() {
 		})
 	}
 
-	if config != "" {
-		loadConfig()
-	}
-
-	fm, err := filemanager.New(database, filemanager.User{
-		AllowCommands: allowCommands,
-		AllowEdit:     allowEdit,
-		AllowNew:      allowNew,
-		Commands:      strings.Split(strings.TrimSpace(commands), " "),
+	// Create a File Manager instance.
+	fm, err := filemanager.New(viper.GetString("Database"), filemanager.User{
+		AllowCommands: viper.GetBool("AllowCommands"),
+		AllowEdit:     viper.GetBool("AllowEdit"),
+		AllowNew:      viper.GetBool("AllowNew"),
+		Commands:      viper.GetStringSlice("Commands"),
 		Rules:         []*filemanager.Rule{},
 		CSS:           "",
-		FileSystem:    fileutils.Dir(scope),
+		FileSystem:    fileutils.Dir(viper.GetString("Scope")),
 	})
 
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	fm.SetBaseURL("/")
-	fm.SetPrefixURL("/")
-
-	listener, err := net.Listen("tcp", addr+":"+port)
+	// Builds the address and a listener.
+	laddr := viper.GetString("Address") + ":" + viper.GetString("Port")
+	listener, err := net.Listen("tcp", laddr)
 	if err != nil {
 		log.Fatal(err)
 	}
 
+	// Tell the user the port in which is listening.
 	fmt.Println("Listening on", listener.Addr().String())
+
+	// Starts the server.
 	if err := http.Serve(listener, fm); err != nil {
 		log.Fatal(err)
 	}
 }
-
-func loadConfig() {
-	file, err := ioutil.ReadFile(config)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	var conf *confFile
-	err = json.Unmarshal(file, &conf)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	database = conf.Database
-	scope = conf.Scope
-	addr = conf.Address
-	logfile = conf.Logger
-	commands = strings.Join(conf.Commands, " ")
-	port = strconv.Itoa(conf.Port)
-	allowNew = conf.AllowNew
-	allowEdit = conf.AllowEdit
-	allowCommands = conf.AllowCommands
-}