Donut mode will now take multiple paths as argument, updated docs as well

main.go

@@ -94,6 +94,9 @@ EXAMPLES:
   2. Create a temporary donut volume under "/tmp"
       $ minio mode {{.Name}} /tmp
 
+  3. Create a donut volume under collection of paths
+      $ minio mode {{.Name}} /mnt/backup2014feb /mnt/backup2014feb
+
 `,
 }
 
@@ -135,7 +138,7 @@ func (f webFactory) getStartServerFunc() startServerFunc {
 
 type donutFactory struct {
 	server.Config
-	path string
+	paths []string
 }
 
 func (f donutFactory) getStartServerFunc() startServerFunc {
@@ -146,7 +149,7 @@ func (f donutFactory) getStartServerFunc() startServerFunc {
 		httpConfig.CertFile = f.CertFile
 		httpConfig.KeyFile = f.KeyFile
 		httpConfig.Websocket = false
-		_, _, driver := donut.Start(f.path)
+		_, _, driver := donut.Start(f.paths)
 		ctrl, status, _ := httpserver.Start(api.HTTPHandler(f.Domain, driver), httpConfig)
 		return ctrl, status
 	}
@@ -223,14 +226,21 @@ func runDonut(c *cli.Context) {
 	if len(c.Args()) < 1 {
 		cli.ShowCommandHelpAndExit(c, "donut", 1) // last argument is exit code
 	}
-	p := c.Args().First()
-	if strings.TrimSpace(p) == "" {
-		p = path.Join(u.HomeDir, "minio-storage", "donut")
+
+	// supporting multiple paths
+	var paths []string
+	if strings.TrimSpace(c.Args().First()) == "" {
+		p := path.Join(u.HomeDir, "minio-storage", "donut")
+		paths = append(paths, p)
+	} else {
+		for _, arg := range c.Args() {
+			paths = append(paths, strings.TrimSpace(arg))
+		}
 	}
 	apiServerConfig := getAPIServerConfig(c)
 	donutDriver := donutFactory{
 		Config: apiServerConfig,
-		path:   p,
+		paths:  paths,
 	}
 	apiServer := donutDriver.getStartServerFunc()
 	webServer := getWebServerConfigFunc(c)

pkg/api/api_test.go

@@ -70,7 +70,9 @@ var _ = Suite(&MySuite{
 var _ = Suite(&MySuite{
 	initDriver: func() (drivers.Driver, string) {
 		root, _ := ioutil.TempDir(os.TempDir(), "minio-api")
-		_, _, driver := donut.Start(root)
+		var roots []string
+		roots = append(roots, root)
+		_, _, driver := donut.Start(roots)
 		return driver, root
 	},
 })

pkg/storage/drivers/donut/donut.go

@@ -38,7 +38,7 @@ import (
 // donutDriver - creates a new single disk drivers driver using donut
 type donutDriver struct {
 	donut donut.Donut
-	path  string
+	paths []string
 }
 
 const (
@@ -47,9 +47,9 @@ const (
 
 // This is a dummy nodeDiskMap which is going to be deprecated soon
 // once the Management API is standardized, this map is useful for now
-// to show multi disk API correctness behavior.
+// to show multi disk API correctness and parity calculation
 //
-// This should be obtained from donut configuration file
+// Ideally this should be obtained from per node configuration file
 func createNodeDiskMap(p string) map[string][]string {
 	nodes := make(map[string][]string)
 	nodes["localhost"] = make([]string, 16)
@@ -65,24 +65,51 @@ func createNodeDiskMap(p string) map[string][]string {
 	return nodes
 }
 
+// This is a dummy nodeDiskMap which is going to be deprecated soon
+// once the Management API is standardized, and we have way of adding
+// and removing disks. This is useful for now to take inputs from CLI
+func createNodeDiskMapFromSlice(paths []string) map[string][]string {
+	diskPaths := make([]string, len(paths))
+	nodes := make(map[string][]string)
+	for i, p := range paths {
+		diskPath := path.Join(p, strconv.Itoa(i))
+		if _, err := os.Stat(diskPath); err != nil {
+			if os.IsNotExist(err) {
+				os.MkdirAll(diskPath, 0700)
+			}
+		}
+		diskPaths[i] = diskPath
+	}
+	nodes["localhost"] = diskPaths
+	return nodes
+}
+
 // Start a single disk subsystem
-func Start(path string) (chan<- string, <-chan error, drivers.Driver) {
+func Start(paths []string) (chan<- string, <-chan error, drivers.Driver) {
 	ctrlChannel := make(chan string)
 	errorChannel := make(chan error)
-	errParams := map[string]string{"path": path}
 
-	// Soon to be user configurable, when Management API
-	// is finished we remove "default" to something
-	// which is passed down from configuration
-	donut, err := donut.NewDonut("default", createNodeDiskMap(path))
-	if err != nil {
-		err = iodine.New(err, errParams)
-		log.Error.Println(err)
+	// Soon to be user configurable, when Management API is available
+	// we should remove "default" to something which is passed down
+	// from configuration paramters
+	var d donut.Donut
+	var err error
+	if len(paths) == 1 {
+		d, err = donut.NewDonut("default", createNodeDiskMap(paths[0]))
+		if err != nil {
+			err = iodine.New(err, nil)
+			log.Error.Println(err)
+		}
+	} else {
+		d, err = donut.NewDonut("default", createNodeDiskMapFromSlice(paths))
+		if err != nil {
+			err = iodine.New(err, nil)
+			log.Error.Println(err)
+		}
 	}
-
 	s := new(donutDriver)
-	s.donut = donut
-	s.path = path
+	s.donut = d
+	s.paths = paths
 
 	go start(ctrlChannel, errorChannel, s)
 	return ctrlChannel, errorChannel, s
@@ -143,7 +170,7 @@ func (d donutDriver) GetBucketMetadata(bucketName string) (drivers.BucketMetadat
 	}
 	acl, ok := metadata["acl"]
 	if !ok {
-		return drivers.BucketMetadata{}, iodine.New(drivers.BackendCorrupted{Path: d.path}, nil)
+		return drivers.BucketMetadata{}, iodine.New(drivers.BackendCorrupted{}, nil)
 	}
 	bucketMetadata := drivers.BucketMetadata{
 		Name:    metadata["name"],

pkg/storage/drivers/donut/donut_test.go

@@ -32,13 +32,14 @@ type MySuite struct{}
 var _ = Suite(&MySuite{})
 
 func (s *MySuite) TestAPISuite(c *C) {
-	//	c.Skip("Not Implemented")
 	var storageList []string
 	create := func() drivers.Driver {
-		path, err := ioutil.TempDir(os.TempDir(), "minio-fs-")
+		var paths []string
+		p, err := ioutil.TempDir(os.TempDir(), "minio-fs-")
 		c.Check(err, IsNil)
-		storageList = append(storageList, path)
-		_, _, store := Start(path) // TODO Make InMemory driver
+		storageList = append(storageList, p)
+		paths = append(paths, p)
+		_, _, store := Start(paths)
 		return store
 	}
 	drivers.APITestSuite(c, create)