backend/server: remove id and version from backend

backend/local/local.go

@@ -1,9 +1,6 @@
 package local
 
 import (
-	"crypto/rand"
-	"crypto/sha256"
-	"encoding/hex"
 	"errors"
 	"fmt"
 	"io"
@@ -11,7 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
-	"strings"
 
 	"github.com/restic/restic/backend"
 )
@@ -19,9 +15,7 @@ import (
 var ErrWrongData = errors.New("wrong data returned by backend, checksum does not match")
 
 type Local struct {
-	p   string
-	ver uint
-	id  string
+	p string
 }
 
 // Open opens the local backend at dir.
@@ -36,68 +30,19 @@ func Open(dir string) (*Local, error) {
 		filepath.Join(dir, backend.Paths.Temp),
 	}
 
-	// test if all necessary dirs and files are there
+	// test if all necessary dirs are there
 	for _, d := range items {
 		if _, err := os.Stat(d); err != nil {
 			return nil, fmt.Errorf("%s does not exist", d)
 		}
 	}
 
-	// read version file
-	f, err := os.Open(filepath.Join(dir, backend.Paths.Version))
-	if err != nil {
-		return nil, fmt.Errorf("unable to read version file: %v\n", err)
-	}
-
-	var version uint
-	n, err := fmt.Fscanf(f, "%d", &version)
-	if err != nil {
-		return nil, err
-	}
-
-	if n != 1 {
-		return nil, errors.New("could not read version from file")
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	// check version
-	if version != backend.Version {
-		return nil, fmt.Errorf("wrong version %d", version)
-	}
-
-	// read ID
-	f, err = os.Open(filepath.Join(dir, backend.Paths.ID))
-	if err != nil {
-		return nil, err
-	}
-
-	buf, err := ioutil.ReadAll(f)
-	if err != nil {
-		return nil, err
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	id := strings.TrimSpace(string(buf))
-	if err != nil {
-		return nil, err
-	}
-
-	return &Local{p: dir, ver: version, id: id}, nil
+	return &Local{p: dir}, nil
 }
 
 // Create creates all the necessary files and directories for a new local
-// backend at dir.
+// backend at dir. Afterwards a new config blob should must created.
 func Create(dir string) (*Local, error) {
-	versionFile := filepath.Join(dir, backend.Paths.Version)
-	idFile := filepath.Join(dir, backend.Paths.ID)
 	dirs := []string{
 		dir,
 		filepath.Join(dir, backend.Paths.Data),
@@ -108,15 +53,10 @@ func Create(dir string) (*Local, error) {
 		filepath.Join(dir, backend.Paths.Temp),
 	}
 
-	// test if files already exist
-	_, err := os.Lstat(versionFile)
+	// test if config file already exist
+	_, err := os.Lstat(backend.Paths.Config)
 	if err == nil {
-		return nil, errors.New("version file already exists")
-	}
-
-	_, err = os.Lstat(idFile)
-	if err == nil {
-		return nil, errors.New("id file already exists")
+		return nil, errors.New("config file already exists")
 	}
 
 	// test if directories already exist
@@ -134,44 +74,6 @@ func Create(dir string) (*Local, error) {
 		}
 	}
 
-	// create version file
-	f, err := os.Create(versionFile)
-	if err != nil {
-		return nil, err
-	}
-
-	_, err = fmt.Fprintf(f, "%d\n", backend.Version)
-	if err != nil {
-		return nil, err
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
-	// create ID file
-	id := make([]byte, sha256.Size)
-	_, err = rand.Read(id)
-	if err != nil {
-		return nil, err
-	}
-
-	f, err = os.Create(idFile)
-	if err != nil {
-		return nil, err
-	}
-
-	_, err = fmt.Fprintln(f, hex.EncodeToString(id))
-	if err != nil {
-		return nil, err
-	}
-
-	err = f.Close()
-	if err != nil {
-		return nil, err
-	}
-
 	// open backend
 	return Open(dir)
 }
@@ -265,6 +167,10 @@ func (b *Local) Create() (backend.Blob, error) {
 
 // Construct path for given Type and name.
 func filename(base string, t backend.Type, name string) string {
+	if t == backend.Config {
+		return filepath.Join(base, "config")
+	}
+
 	return filepath.Join(dirname(base, t, name), name)
 }
 
@@ -376,16 +282,6 @@ func (b *Local) List(t backend.Type, done <-chan struct{}) <-chan string {
 	return ch
 }
 
-// Version returns the version of this local backend.
-func (b *Local) Version() uint {
-	return b.ver
-}
-
-// ID returns the ID of this local backend.
-func (b *Local) ID() string {
-	return b.id
-}
-
 // Delete removes the repository and all files.
 func (b *Local) Delete() error { return os.RemoveAll(b.p) }