init: Add flag to specify created repository version

cmd/restic/cmd_init.go

@@ -1,10 +1,13 @@
 package main
 
 import (
+	"strconv"
+
 	"github.com/restic/chunker"
 	"github.com/restic/restic/internal/backend/location"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/repository"
+	"github.com/restic/restic/internal/restic"
 
 	"github.com/spf13/cobra"
 )
@@ -30,6 +33,7 @@ Exit status is 0 if the command was successful, and non-zero if there was any er
 type InitOptions struct {
 	secondaryRepoOptions
 	CopyChunkerParameters bool
+	RepositoryVersion     string
 }
 
 var initOptions InitOptions
@@ -40,9 +44,26 @@ func init() {
 	f := cmdInit.Flags()
 	initSecondaryRepoOptions(f, &initOptions.secondaryRepoOptions, "secondary", "to copy chunker parameters from")
 	f.BoolVar(&initOptions.CopyChunkerParameters, "copy-chunker-params", false, "copy chunker parameters from the secondary repository (useful with the copy command)")
+	f.StringVar(&initOptions.RepositoryVersion, "repository-version", "stable", "repository format version to use, allowed values are a format version, 'latest' and 'stable'")
 }
 
 func runInit(opts InitOptions, gopts GlobalOptions, args []string) error {
+	var version uint
+	if opts.RepositoryVersion == "latest" || opts.RepositoryVersion == "" {
+		version = restic.MaxRepoVersion
+	} else if opts.RepositoryVersion == "stable" {
+		version = restic.StableRepoVersion
+	} else {
+		v, err := strconv.ParseUint(opts.RepositoryVersion, 10, 32)
+		if err != nil {
+			return errors.Fatal("invalid repository version")
+		}
+		version = uint(v)
+	}
+	if version < restic.MinRepoVersion || version > restic.MaxRepoVersion {
+		return errors.Fatalf("only repository versions between %v and %v are allowed", restic.MinRepoVersion, restic.MaxRepoVersion)
+	}
+
 	chunkerPolynomial, err := maybeReadChunkerPolynomial(opts, gopts)
 	if err != nil {
 		return err
@@ -67,7 +88,7 @@ func runInit(opts InitOptions, gopts GlobalOptions, args []string) error {
 
 	s := repository.New(be)
 
-	err = s.Init(gopts.ctx, gopts.password, chunkerPolynomial)
+	err = s.Init(gopts.ctx, version, gopts.password, chunkerPolynomial)
 	if err != nil {
 		return errors.Fatalf("create key in repository at %s failed: %v\n", location.StripPassword(gopts.Repo), err)
 	}

internal/repository/repository.go

@@ -661,7 +661,15 @@ func (r *Repository) SearchKey(ctx context.Context, password string, maxKeys int
 
 // Init creates a new master key with the supplied password, initializes and
 // saves the repository config.
-func (r *Repository) Init(ctx context.Context, password string, chunkerPolynomial *chunker.Pol) error {
+func (r *Repository) Init(ctx context.Context, version uint, password string, chunkerPolynomial *chunker.Pol) error {
+	if version > restic.MaxRepoVersion {
+		return fmt.Errorf("repo version %v too high", version)
+	}
+
+	if version < restic.MinRepoVersion {
+		return fmt.Errorf("repo version %v too low", version)
+	}
+
 	has, err := r.be.Test(ctx, restic.Handle{Type: restic.ConfigFile})
 	if err != nil {
 		return err
@@ -670,7 +678,7 @@ func (r *Repository) Init(ctx context.Context, password string, chunkerPolynomia
 		return errors.New("repository master key and config already initialized")
 	}
 
-	cfg, err := restic.CreateConfig()
+	cfg, err := restic.CreateConfig(version)
 	if err != nil {
 		return err
 	}

internal/restic/config.go

@@ -18,9 +18,12 @@ type Config struct {
 	ChunkerPolynomial chunker.Pol `json:"chunker_polynomial"`
 }
 
-// RepoVersion is the version that is written to the config when a repository
+const MinRepoVersion = 1
+const MaxRepoVersion = 2
+
+// StableRepoVersion is the version that is written to the config when a repository
 // is newly created with Init().
-const RepoVersion = 1
+const StableRepoVersion = 1
 
 // JSONUnpackedLoader loads unpacked JSON.
 type JSONUnpackedLoader interface {
@@ -29,7 +32,7 @@ type JSONUnpackedLoader interface {
 
 // CreateConfig creates a config file with a randomly selected polynomial and
 // ID.
-func CreateConfig() (Config, error) {
+func CreateConfig(version uint) (Config, error) {
 	var (
 		err error
 		cfg Config
@@ -41,7 +44,7 @@ func CreateConfig() (Config, error) {
 	}
 
 	cfg.ID = NewRandomID().String()
-	cfg.Version = RepoVersion
+	cfg.Version = version
 
 	debug.Log("New config: %#v", cfg)
 	return cfg, nil
@@ -52,7 +55,7 @@ func TestCreateConfig(t testing.TB, pol chunker.Pol) (cfg Config) {
 	cfg.ChunkerPolynomial = pol
 
 	cfg.ID = NewRandomID().String()
-	cfg.Version = RepoVersion
+	cfg.Version = StableRepoVersion
 
 	return cfg
 }
@@ -77,7 +80,7 @@ func LoadConfig(ctx context.Context, r JSONUnpackedLoader) (Config, error) {
 		return Config{}, err
 	}
 
-	if cfg.Version != RepoVersion {
+	if cfg.Version < MinRepoVersion || cfg.Version > MaxRepoVersion {
 		return Config{}, errors.Errorf("unsupported repository version %v", cfg.Version)
 	}
 

internal/restic/config_test.go

@@ -32,7 +32,7 @@ func TestConfig(t *testing.T) {
 		return restic.ID{}, nil
 	}
 
-	cfg1, err := restic.CreateConfig()
+	cfg1, err := restic.CreateConfig(restic.MaxRepoVersion)
 	rtest.OK(t, err)
 
 	_, err = saver(save).SaveJSONUnpacked(restic.ConfigFile, cfg1)