drive: factor common authentication code into googleauth module

In preparation for Google Cloud Storage support

drive/drive.go

@@ -16,7 +16,6 @@ package drive
 // * files with / in name
 
 import (
-	"encoding/json"
 	"fmt"
 	"io"
 	"log"
@@ -28,9 +27,9 @@ import (
 	"sync"
 	"time"
 
-	"code.google.com/p/goauth2/oauth"
 	"code.google.com/p/google-api-go-client/drive/v2"
 	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/googleauth"
 	"github.com/ogier/pflag"
 )
 
@@ -47,14 +46,22 @@ const (
 var (
 	// Flags
 	driveFullList = pflag.BoolP("drive-full-list", "", true, "Use a full listing for directory list. More data but usually quicker.")
+	// Description of how to auth for this app
+	driveAuth = &googleauth.Auth{
+		Scope:               "https://www.googleapis.com/auth/drive",
+		DefaultClientId:     rcloneClientId,
+		DefaultClientSecret: rcloneClientSecret,
+	}
 )
 
 // Register with Fs
 func init() {
 	fs.Register(&fs.FsInfo{
-		Name:   "drive",
+		Name:  "drive",
-		NewFs:  NewFs,
+		NewFs: NewFs,
-		Config: Config,
+		Config: func(name string) {
+			driveAuth.Config(name)
+		},
 		Options: []fs.Option{{
 			Name: "client_id",
 			Help: "Google Application Client Id - leave blank to use rclone's.",
@@ -65,77 +72,6 @@ func init() {
 	})
 }
 
-// Configuration helper - called after the user has put in the defaults
-func Config(name string) {
-	// See if already have a token
-	tokenString := fs.ConfigFile.MustValue(name, "token")
-	if tokenString != "" {
-		fmt.Printf("Already have a drive token - refresh?\n")
-		if !fs.Confirm() {
-			return
-		}
-	}
-
-	// Get a drive transport
-	t, err := newDriveTransport(name)
-	if err != nil {
-		log.Fatalf("Couldn't make drive transport: %v", err)
-	}
-
-	// Generate a URL for the user to visit for authorization.
-	authUrl := t.Config.AuthCodeURL("state")
-	fmt.Printf("Go to the following link in your browser\n")
-	fmt.Printf("%s\n", authUrl)
-	fmt.Printf("Log in, then type paste the token that is returned in the browser here\n")
-
-	// Read the code, and exchange it for a token.
-	fmt.Printf("Enter verification code> ")
-	authCode := fs.ReadLine()
-	_, err = t.Exchange(authCode)
-	if err != nil {
-		log.Fatalf("Failed to get token: %v", err)
-	}
-
-}
-
-// A token cache to save the token in the config file section named
-type tokenCache string
-
-// Get the token from the config file - returns an error if it isn't present
-func (name tokenCache) Token() (*oauth.Token, error) {
-	tokenString, err := fs.ConfigFile.GetValue(string(name), "token")
-	if err != nil {
-		return nil, err
-	}
-	if tokenString == "" {
-		return nil, fmt.Errorf("Empty token found - please reconfigure")
-	}
-	token := new(oauth.Token)
-	err = json.Unmarshal([]byte(tokenString), token)
-	if err != nil {
-		return nil, err
-	}
-	return token, nil
-
-}
-
-// Save the token to the config file
-//
-// This saves the config file if it changes
-func (name tokenCache) PutToken(token *oauth.Token) error {
-	tokenBytes, err := json.Marshal(token)
-	if err != nil {
-		return err
-	}
-	tokenString := string(tokenBytes)
-	old := fs.ConfigFile.MustValue(string(name), "token")
-	if tokenString != old {
-		fs.ConfigFile.SetValue(string(name), "token", tokenString)
-		fs.SaveConfig()
-	}
-	return nil
-}
-
 // FsDrive represents a remote drive server
 type FsDrive struct {
 	svc          *drive.Service // the connection to the drive server
@@ -268,39 +204,9 @@ OUTER:
 	return
 }
 
-// Makes a new drive transport from the config
-func newDriveTransport(name string) (*oauth.Transport, error) {
-	clientId := fs.ConfigFile.MustValue(name, "client_id")
-	if clientId == "" {
-		clientId = rcloneClientId
-	}
-	clientSecret := fs.ConfigFile.MustValue(name, "client_secret")
-	if clientSecret == "" {
-		clientSecret = rcloneClientSecret
-	}
-
-	// Settings for authorization.
-	var driveConfig = &oauth.Config{
-		ClientId:     clientId,
-		ClientSecret: clientSecret,
-		Scope:        "https://www.googleapis.com/auth/drive",
-		RedirectURL:  "urn:ietf:wg:oauth:2.0:oob",
-		AuthURL:      "https://accounts.google.com/o/oauth2/auth",
-		TokenURL:     "https://accounts.google.com/o/oauth2/token",
-		TokenCache:   tokenCache(name),
-	}
-
-	t := &oauth.Transport{
-		Config:    driveConfig,
-		Transport: http.DefaultTransport,
-	}
-
-	return t, nil
-}
-
 // NewFs contstructs an FsDrive from the path, container:path
 func NewFs(name, path string) (fs.Fs, error) {
-	t, err := newDriveTransport(name)
+	t, err := driveAuth.NewTransport(name)
 	if err != nil {
 		return nil, err
 	}
@@ -309,18 +215,12 @@ func NewFs(name, path string) (fs.Fs, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	f := &FsDrive{
 		root:     root,
 		dirCache: newDirCache(),
 	}
 
-	// Try to pull the token from the cache; if this fails, we need to get one.
-	token, err := t.Config.TokenCache.Token()
-	if err != nil {
-		return nil, fmt.Errorf("Failed to get token: %s", err)
-	}
-	t.Token = token
-
 	// Create a new authorized Drive client.
 	f.client = t.Client()
 	f.svc, err = drive.New(f.client)

googleauth/googleauth.go

@@ -0,0 +1,138 @@
+// Common authentication between Google Drive and Google Cloud Storage
+package googleauth
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+
+	"code.google.com/p/goauth2/oauth"
+	"github.com/ncw/rclone/fs"
+)
+
+// A token cache to save the token in the config file section named
+type TokenCache string
+
+// Get the token from the config file - returns an error if it isn't present
+func (name TokenCache) Token() (*oauth.Token, error) {
+	tokenString, err := fs.ConfigFile.GetValue(string(name), "token")
+	if err != nil {
+		return nil, err
+	}
+	if tokenString == "" {
+		return nil, fmt.Errorf("Empty token found - please reconfigure")
+	}
+	token := new(oauth.Token)
+	err = json.Unmarshal([]byte(tokenString), token)
+	if err != nil {
+		return nil, err
+	}
+	return token, nil
+
+}
+
+// Save the token to the config file
+//
+// This saves the config file if it changes
+func (name TokenCache) PutToken(token *oauth.Token) error {
+	tokenBytes, err := json.Marshal(token)
+	if err != nil {
+		return err
+	}
+	tokenString := string(tokenBytes)
+	old := fs.ConfigFile.MustValue(string(name), "token")
+	if tokenString != old {
+		fs.ConfigFile.SetValue(string(name), "token", tokenString)
+		fs.SaveConfig()
+	}
+	return nil
+}
+
+// Auth contains information to authenticate an app against google services
+type Auth struct {
+	Scope               string
+	DefaultClientId     string
+	DefaultClientSecret string
+}
+
+// Makes a new transport using authorisation from the config
+//
+// Doesn't have a token yet
+func (auth *Auth) newTransport(name string) (*oauth.Transport, error) {
+	clientId := fs.ConfigFile.MustValue(name, "client_id")
+	if clientId == "" {
+		clientId = auth.DefaultClientId
+	}
+	clientSecret := fs.ConfigFile.MustValue(name, "client_secret")
+	if clientSecret == "" {
+		clientSecret = auth.DefaultClientSecret
+	}
+
+	// Settings for authorization.
+	var config = &oauth.Config{
+		ClientId:     clientId,
+		ClientSecret: clientSecret,
+		Scope:        auth.Scope,
+		RedirectURL:  "urn:ietf:wg:oauth:2.0:oob",
+		AuthURL:      "https://accounts.google.com/o/oauth2/auth",
+		TokenURL:     "https://accounts.google.com/o/oauth2/token",
+		TokenCache:   TokenCache(name),
+	}
+
+	t := &oauth.Transport{
+		Config:    config,
+		Transport: http.DefaultTransport,
+	}
+
+	return t, nil
+}
+
+// Makes a new transport using authorisation from the config with token
+func (auth *Auth) NewTransport(name string) (*oauth.Transport, error) {
+	t, err := auth.newTransport(name)
+	if err != nil {
+		return nil, err
+	}
+
+	// Try to pull the token from the cache; if this fails, we need to get one.
+	token, err := t.Config.TokenCache.Token()
+	if err != nil {
+		return nil, fmt.Errorf("Failed to get token: %s", err)
+	}
+	t.Token = token
+
+	return t, nil
+}
+
+// Configuration helper - called after the user has put in the defaults
+func (auth *Auth) Config(name string) {
+	// See if already have a token
+	tokenString := fs.ConfigFile.MustValue(name, "token")
+	if tokenString != "" {
+		fmt.Printf("Already have a token - refresh?\n")
+		if !fs.Confirm() {
+			return
+		}
+	}
+
+	// Get a transport
+	t, err := auth.newTransport(name)
+	if err != nil {
+		log.Fatalf("Couldn't make transport: %v", err)
+	}
+
+	// Generate a URL for the user to visit for authorization.
+	authUrl := t.Config.AuthCodeURL("state")
+	fmt.Printf("Go to the following link in your browser\n")
+	fmt.Printf("%s\n", authUrl)
+	fmt.Printf("Log in, then type paste the token that is returned in the browser here\n")
+
+	// Read the code, and exchange it for a token.
+	fmt.Printf("Enter verification code> ")
+	authCode := fs.ReadLine()
+	_, err = t.Exchange(authCode)
+	if err != nil {
+		log.Fatalf("Failed to get token: %v", err)
+	}
+}