Merge pull request #2606 from middelink/fix-323

Add copy functionality.

cmd/restic/cmd_copy.go

@@ -0,0 +1,259 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/restic/restic/internal/debug"
+	"github.com/restic/restic/internal/errors"
+	"github.com/restic/restic/internal/restic"
+
+	"github.com/spf13/cobra"
+)
+
+var cmdCopy = &cobra.Command{
+	Use:   "copy [flags] [snapshotID ...]",
+	Short: "Copy snapshots from one repository to another",
+	Long: `
+The "copy" command copies one or more snapshots from one repository to another
+repository. Note that this will have to read (download) and write (upload) the
+entire snapshot(s) due to the different encryption keys on the source and
+destination, and that transferred files are not re-chunked, which may break
+their deduplication.
+`,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return runCopy(copyOptions, globalOptions, args)
+	},
+}
+
+// CopyOptions bundles all options for the copy command.
+type CopyOptions struct {
+	Repo            string
+	password        string
+	PasswordFile    string
+	PasswordCommand string
+	KeyHint         string
+	Hosts           []string
+	Tags            restic.TagLists
+	Paths           []string
+}
+
+var copyOptions CopyOptions
+
+func init() {
+	cmdRoot.AddCommand(cmdCopy)
+
+	f := cmdCopy.Flags()
+	f.StringVarP(&copyOptions.Repo, "repo2", "", os.Getenv("RESTIC_REPOSITORY2"), "destination repository to copy snapshots to (default: $RESTIC_REPOSITORY2)")
+	f.StringVarP(&copyOptions.PasswordFile, "password-file2", "", os.Getenv("RESTIC_PASSWORD_FILE2"), "read the destination repository password from a file (default: $RESTIC_PASSWORD_FILE2)")
+	f.StringVarP(&copyOptions.KeyHint, "key-hint2", "", os.Getenv("RESTIC_KEY_HINT2"), "key ID of key to try decrypting the destination repository first (default: $RESTIC_KEY_HINT2)")
+	f.StringVarP(&copyOptions.PasswordCommand, "password-command2", "", os.Getenv("RESTIC_PASSWORD_COMMAND2"), "specify a shell command to obtain a password for the destination repository (default: $RESTIC_PASSWORD_COMMAND2)")
+
+	f.StringArrayVarP(&copyOptions.Hosts, "host", "H", nil, "only consider snapshots for this `host`, when no snapshot ID is given (can be specified multiple times)")
+	f.Var(&copyOptions.Tags, "tag", "only consider snapshots which include this `taglist`, when no snapshot ID is given")
+	f.StringArrayVar(&copyOptions.Paths, "path", nil, "only consider snapshots which include this (absolute) `path`, when no snapshot ID is given")
+}
+
+func runCopy(opts CopyOptions, gopts GlobalOptions, args []string) error {
+	if opts.Repo == "" {
+		return errors.Fatal("Please specify a destination repository location (--repo2)")
+	}
+	var err error
+	dstGopts := gopts
+	dstGopts.Repo = opts.Repo
+	dstGopts.PasswordFile = opts.PasswordFile
+	dstGopts.PasswordCommand = opts.PasswordCommand
+	dstGopts.KeyHint = opts.KeyHint
+	if opts.password != "" {
+		dstGopts.password = opts.password
+	} else {
+		dstGopts.password, err = resolvePassword(dstGopts, "RESTIC_PASSWORD2")
+		if err != nil {
+			return err
+		}
+	}
+	dstGopts.password, err = ReadPassword(dstGopts, "enter password for destination repository: ")
+	if err != nil {
+		return err
+	}
+
+	ctx, cancel := context.WithCancel(gopts.ctx)
+	defer cancel()
+
+	srcRepo, err := OpenRepository(gopts)
+	if err != nil {
+		return err
+	}
+
+	dstRepo, err := OpenRepository(dstGopts)
+	if err != nil {
+		return err
+	}
+
+	srcLock, err := lockRepo(srcRepo)
+	defer unlockRepo(srcLock)
+	if err != nil {
+		return err
+	}
+
+	dstLock, err := lockRepo(dstRepo)
+	defer unlockRepo(dstLock)
+	if err != nil {
+		return err
+	}
+
+	debug.Log("Loading source index")
+	if err := srcRepo.LoadIndex(ctx); err != nil {
+		return err
+	}
+
+	debug.Log("Loading destination index")
+	if err := dstRepo.LoadIndex(ctx); err != nil {
+		return err
+	}
+
+	dstSnapshotByOriginal := make(map[restic.ID][]*restic.Snapshot)
+	for sn := range FindFilteredSnapshots(ctx, dstRepo, opts.Hosts, opts.Tags, opts.Paths, nil) {
+		if sn.Original != nil && !sn.Original.IsNull() {
+			dstSnapshotByOriginal[*sn.Original] = append(dstSnapshotByOriginal[*sn.Original], sn)
+		}
+		// also consider identical snapshot copies
+		dstSnapshotByOriginal[*sn.ID()] = append(dstSnapshotByOriginal[*sn.ID()], sn)
+	}
+
+	cloner := &treeCloner{
+		srcRepo:      srcRepo,
+		dstRepo:      dstRepo,
+		visitedTrees: restic.NewIDSet(),
+		buf:          nil,
+	}
+
+	for sn := range FindFilteredSnapshots(ctx, srcRepo, opts.Hosts, opts.Tags, opts.Paths, args) {
+		Verbosef("\nsnapshot %s of %v at %s)\n", sn.ID().Str(), sn.Paths, sn.Time)
+
+		// check whether the destination has a snapshot with the same persistent ID which has similar snapshot fields
+		srcOriginal := *sn.ID()
+		if sn.Original != nil {
+			srcOriginal = *sn.Original
+		}
+		if originalSns, ok := dstSnapshotByOriginal[srcOriginal]; ok {
+			isCopy := false
+			for _, originalSn := range originalSns {
+				if similarSnapshots(originalSn, sn) {
+					Verbosef("skipping source snapshot %s, was already copied to snapshot %s\n", sn.ID().Str(), originalSn.ID().Str())
+					isCopy = true
+					break
+				}
+			}
+			if isCopy {
+				continue
+			}
+		}
+		Verbosef("  copy started, this may take a while...\n")
+
+		if err := cloner.copyTree(ctx, *sn.Tree); err != nil {
+			return err
+		}
+		debug.Log("tree copied")
+
+		if err = dstRepo.Flush(ctx); err != nil {
+			return err
+		}
+		debug.Log("flushed packs and saved index")
+
+		// save snapshot
+		sn.Parent = nil // Parent does not have relevance in the new repo.
+		// Use Original as a persistent snapshot ID
+		if sn.Original == nil {
+			sn.Original = sn.ID()
+		}
+		newID, err := dstRepo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
+		if err != nil {
+			return err
+		}
+		Verbosef("snapshot %s saved\n", newID.Str())
+	}
+	return nil
+}
+
+func similarSnapshots(sna *restic.Snapshot, snb *restic.Snapshot) bool {
+	// everything except Parent and Original must match
+	if !sna.Time.Equal(snb.Time) || !sna.Tree.Equal(*snb.Tree) || sna.Hostname != snb.Hostname ||
+		sna.Username != snb.Username || sna.UID != snb.UID || sna.GID != snb.GID ||
+		len(sna.Paths) != len(snb.Paths) || len(sna.Excludes) != len(snb.Excludes) ||
+		len(sna.Tags) != len(snb.Tags) {
+		return false
+	}
+	if !sna.HasPaths(snb.Paths) || !sna.HasTags(snb.Tags) {
+		return false
+	}
+	for i, a := range sna.Excludes {
+		if a != snb.Excludes[i] {
+			return false
+		}
+	}
+	return true
+}
+
+type treeCloner struct {
+	srcRepo      restic.Repository
+	dstRepo      restic.Repository
+	visitedTrees restic.IDSet
+	buf          []byte
+}
+
+func (t *treeCloner) copyTree(ctx context.Context, treeID restic.ID) error {
+	// We have already processed this tree
+	if t.visitedTrees.Has(treeID) {
+		return nil
+	}
+
+	tree, err := t.srcRepo.LoadTree(ctx, treeID)
+	if err != nil {
+		return fmt.Errorf("LoadTree(%v) returned error %v", treeID.Str(), err)
+	}
+	t.visitedTrees.Insert(treeID)
+
+	// Do we already have this tree blob?
+	if !t.dstRepo.Index().Has(treeID, restic.TreeBlob) {
+		newTreeID, err := t.dstRepo.SaveTree(ctx, tree)
+		if err != nil {
+			return fmt.Errorf("SaveTree(%v) returned error %v", treeID.Str(), err)
+		}
+		// Assurance only.
+		if newTreeID != treeID {
+			return fmt.Errorf("SaveTree(%v) returned unexpected id %s", treeID.Str(), newTreeID.Str())
+		}
+	}
+
+	// TODO: parellize this stuff, likely only needed inside a tree.
+
+	for _, entry := range tree.Nodes {
+		// If it is a directory, recurse
+		if entry.Type == "dir" && entry.Subtree != nil {
+			if err := t.copyTree(ctx, *entry.Subtree); err != nil {
+				return err
+			}
+		}
+		// Copy the blobs for this file.
+		for _, blobID := range entry.Content {
+			// Do we already have this data blob?
+			if t.dstRepo.Index().Has(blobID, restic.DataBlob) {
+				continue
+			}
+			debug.Log("Copying blob %s\n", blobID.Str())
+			t.buf, err = t.srcRepo.LoadBlob(ctx, restic.DataBlob, blobID, t.buf)
+			if err != nil {
+				return fmt.Errorf("LoadBlob(%v) returned error %v", blobID, err)
+			}
+
+			_, _, err = t.dstRepo.SaveBlob(ctx, restic.DataBlob, t.buf, blobID, false)
+			if err != nil {
+				return fmt.Errorf("SaveBlob(%v) returned error %v", blobID, err)
+			}
+		}
+	}
+
+	return nil
+}

cmd/restic/global.go

@@ -274,7 +274,7 @@ func Exitf(exitcode int, format string, args ...interface{}) {
 }
 
 // resolvePassword determines the password to be used for opening the repository.
-func resolvePassword(opts GlobalOptions) (string, error) {
+func resolvePassword(opts GlobalOptions, envStr string) (string, error) {
 	if opts.PasswordFile != "" && opts.PasswordCommand != "" {
 		return "", errors.Fatalf("Password file and command are mutually exclusive options")
 	}
@@ -299,7 +299,7 @@ func resolvePassword(opts GlobalOptions) (string, error) {
 		return strings.TrimSpace(string(s)), errors.Wrap(err, "Readfile")
 	}
 
-	if pwd := os.Getenv("RESTIC_PASSWORD"); pwd != "" {
+	if pwd := os.Getenv(envStr); pwd != "" {
 		return pwd, nil
 	}
 

cmd/restic/integration_helpers_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"io/ioutil"
@@ -75,14 +76,13 @@ func sameModTime(fi1, fi2 os.FileInfo) bool {
 	return fi1.ModTime().Equal(fi2.ModTime())
 }
 
-// directoriesEqualContents checks if both directories contain exactly the same
-// contents.
-func directoriesEqualContents(dir1, dir2 string) bool {
+// directoriesContentsDiff returns a diff between both directories. If these
+// contain exactly the same contents, then the diff is an empty string.
+func directoriesContentsDiff(dir1, dir2 string) string {
+	var out bytes.Buffer
 	ch1 := walkDir(dir1)
 	ch2 := walkDir(dir2)
 
-	changes := false
-
 	var a, b *dirEntry
 	for {
 		var ok bool
@@ -106,36 +106,27 @@ func directoriesEqualContents(dir1, dir2 string) bool {
 		}
 
 		if ch1 == nil {
-			fmt.Printf("+%v\n", b.path)
-			changes = true
+			fmt.Fprintf(&out, "+%v\n", b.path)
 		} else if ch2 == nil {
-			fmt.Printf("-%v\n", a.path)
-			changes = true
-		} else if !a.equals(b) {
+			fmt.Fprintf(&out, "-%v\n", a.path)
+		} else if !a.equals(&out, b) {
 			if a.path < b.path {
-				fmt.Printf("-%v\n", a.path)
-				changes = true
+				fmt.Fprintf(&out, "-%v\n", a.path)
 				a = nil
 				continue
 			} else if a.path > b.path {
-				fmt.Printf("+%v\n", b.path)
-				changes = true
+				fmt.Fprintf(&out, "+%v\n", b.path)
 				b = nil
 				continue
 			} else {
-				fmt.Printf("%%%v\n", a.path)
-				changes = true
+				fmt.Fprintf(&out, "%%%v\n", a.path)
 			}
 		}
 
 		a, b = nil, nil
 	}
 
-	if changes {
-		return false
-	}
-
-	return true
+	return out.String()
 }
 
 type dirStat struct {

cmd/restic/integration_helpers_unix_test.go

@@ -4,25 +4,26 @@ package main
 
 import (
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"syscall"
 )
 
-func (e *dirEntry) equals(other *dirEntry) bool {
+func (e *dirEntry) equals(out io.Writer, other *dirEntry) bool {
 	if e.path != other.path {
-		fmt.Fprintf(os.Stderr, "%v: path does not match (%v != %v)\n", e.path, e.path, other.path)
+		fmt.Fprintf(out, "%v: path does not match (%v != %v)\n", e.path, e.path, other.path)
 		return false
 	}
 
 	if e.fi.Mode() != other.fi.Mode() {
-		fmt.Fprintf(os.Stderr, "%v: mode does not match (%v != %v)\n", e.path, e.fi.Mode(), other.fi.Mode())
+		fmt.Fprintf(out, "%v: mode does not match (%v != %v)\n", e.path, e.fi.Mode(), other.fi.Mode())
 		return false
 	}
 
 	if !sameModTime(e.fi, other.fi) {
-		fmt.Fprintf(os.Stderr, "%v: ModTime does not match (%v != %v)\n", e.path, e.fi.ModTime(), other.fi.ModTime())
+		fmt.Fprintf(out, "%v: ModTime does not match (%v != %v)\n", e.path, e.fi.ModTime(), other.fi.ModTime())
 		return false
 	}
 
@@ -30,17 +31,17 @@ func (e *dirEntry) equals(other *dirEntry) bool {
 	stat2, _ := other.fi.Sys().(*syscall.Stat_t)
 
 	if stat.Uid != stat2.Uid {
-		fmt.Fprintf(os.Stderr, "%v: UID does not match (%v != %v)\n", e.path, stat.Uid, stat2.Uid)
+		fmt.Fprintf(out, "%v: UID does not match (%v != %v)\n", e.path, stat.Uid, stat2.Uid)
 		return false
 	}
 
 	if stat.Gid != stat2.Gid {
-		fmt.Fprintf(os.Stderr, "%v: GID does not match (%v != %v)\n", e.path, stat.Gid, stat2.Gid)
+		fmt.Fprintf(out, "%v: GID does not match (%v != %v)\n", e.path, stat.Gid, stat2.Gid)
 		return false
 	}
 
 	if stat.Nlink != stat2.Nlink {
-		fmt.Fprintf(os.Stderr, "%v: Number of links do not match (%v != %v)\n", e.path, stat.Nlink, stat2.Nlink)
+		fmt.Fprintf(out, "%v: Number of links do not match (%v != %v)\n", e.path, stat.Nlink, stat2.Nlink)
 		return false
 	}
 

cmd/restic/integration_helpers_windows_test.go

@@ -4,23 +4,24 @@ package main
 
 import (
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 )
 
-func (e *dirEntry) equals(other *dirEntry) bool {
+func (e *dirEntry) equals(out io.Writer, other *dirEntry) bool {
 	if e.path != other.path {
-		fmt.Fprintf(os.Stderr, "%v: path does not match (%v != %v)\n", e.path, e.path, other.path)
+		fmt.Fprintf(out, "%v: path does not match (%v != %v)\n", e.path, e.path, other.path)
 		return false
 	}
 
 	if e.fi.Mode() != other.fi.Mode() {
-		fmt.Fprintf(os.Stderr, "%v: mode does not match (%v != %v)\n", e.path, e.fi.Mode(), other.fi.Mode())
+		fmt.Fprintf(out, "%v: mode does not match (%v != %v)\n", e.path, e.fi.Mode(), other.fi.Mode())
 		return false
 	}
 
 	if !sameModTime(e.fi, other.fi) {
-		fmt.Fprintf(os.Stderr, "%v: ModTime does not match (%v != %v)\n", e.path, e.fi.ModTime(), other.fi.ModTime())
+		fmt.Fprintf(out, "%v: ModTime does not match (%v != %v)\n", e.path, e.fi.ModTime(), other.fi.ModTime())
 		return false
 	}
 

cmd/restic/integration_test.go

@@ -260,22 +260,18 @@ func testRunPrune(t testing.TB, gopts GlobalOptions) {
 	rtest.OK(t, runPrune(gopts))
 }
 
+func testSetupBackupData(t testing.TB, env *testEnvironment) string {
+	datafile := filepath.Join("testdata", "backup-data.tar.gz")
+	testRunInit(t, env.gopts)
+	rtest.SetupTarTestFixture(t, env.testdata, datafile)
+	return datafile
+}
+
 func TestBackup(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	fd, err := os.Open(datafile)
-	if os.IsNotExist(errors.Cause(err)) {
-		t.Skipf("unable to find data file %q, skipping", datafile)
-		return
-	}
-	rtest.OK(t, err)
-	rtest.OK(t, fd.Close())
-
-	testRunInit(t, env.gopts)
-
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
+	testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	// first backup
@@ -317,9 +313,9 @@ func TestBackup(t *testing.T) {
 	for i, snapshotID := range snapshotIDs {
 		restoredir := filepath.Join(env.base, fmt.Sprintf("restore%d", i))
 		t.Logf("restoring snapshot %v to %v", snapshotID.Str(), restoredir)
-		testRunRestore(t, env.gopts, restoredir, snapshotIDs[0])
-		rtest.Assert(t, directoriesEqualContents(env.testdata, filepath.Join(restoredir, "testdata")),
-			"directories are not equal")
+		testRunRestore(t, env.gopts, restoredir, snapshotID)
+		diff := directoriesContentsDiff(env.testdata, filepath.Join(restoredir, "testdata"))
+		rtest.Assert(t, diff == "", "directories are not equal: %v", diff)
 	}
 
 	testRunCheck(t, env.gopts)
@@ -329,18 +325,7 @@ func TestBackupNonExistingFile(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	fd, err := os.Open(datafile)
-	if os.IsNotExist(errors.Cause(err)) {
-		t.Skipf("unable to find data file %q, skipping", datafile)
-		return
-	}
-	rtest.OK(t, err)
-	rtest.OK(t, fd.Close())
-
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
-	testRunInit(t, env.gopts)
+	testSetupBackupData(t, env)
 	globalOptions.stderr = ioutil.Discard
 	defer func() {
 		globalOptions.stderr = os.Stderr
@@ -503,11 +488,7 @@ func TestBackupErrors(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
-	testRunInit(t, env.gopts)
+	testSetupBackupData(t, env)
 
 	// Assume failure
 	inaccessibleFile := filepath.Join(env.testdata, "0", "0", "9", "0")
@@ -596,10 +577,7 @@ func TestBackupTags(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	testRunInit(t, env.gopts)
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
+	testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	testRunBackup(t, "", []string{env.testdata}, opts, env.gopts)
@@ -622,6 +600,121 @@ func TestBackupTags(t *testing.T) {
 		"expected parent to be %v, got %v", parent.ID, newest.Parent)
 }
 
+func testRunCopy(t testing.TB, srcGopts GlobalOptions, dstGopts GlobalOptions) {
+	copyOpts := CopyOptions{
+		Repo:     dstGopts.Repo,
+		password: dstGopts.password,
+	}
+
+	rtest.OK(t, runCopy(copyOpts, srcGopts, nil))
+}
+
+func TestCopy(t *testing.T) {
+	env, cleanup := withTestEnvironment(t)
+	defer cleanup()
+	env2, cleanup2 := withTestEnvironment(t)
+	defer cleanup2()
+
+	testSetupBackupData(t, env)
+	opts := BackupOptions{}
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9")}, opts, env.gopts)
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9", "2")}, opts, env.gopts)
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9", "3")}, opts, env.gopts)
+	testRunCheck(t, env.gopts)
+
+	testRunInit(t, env2.gopts)
+	testRunCopy(t, env.gopts, env2.gopts)
+
+	snapshotIDs := testRunList(t, "snapshots", env.gopts)
+	copiedSnapshotIDs := testRunList(t, "snapshots", env2.gopts)
+
+	// Check that the copies size seems reasonable
+	rtest.Assert(t, len(snapshotIDs) == len(copiedSnapshotIDs), "expected %v snapshots, found %v",
+		len(snapshotIDs), len(copiedSnapshotIDs))
+	stat := dirStats(env.repo)
+	stat2 := dirStats(env2.repo)
+	sizeDiff := int64(stat.size) - int64(stat2.size)
+	if sizeDiff < 0 {
+		sizeDiff = -sizeDiff
+	}
+	rtest.Assert(t, sizeDiff < int64(stat.size)/50, "expected less than 2%% size difference: %v vs. %v",
+		stat.size, stat2.size)
+
+	// Check integrity of the copy
+	testRunCheck(t, env2.gopts)
+
+	// Check that the copied snapshots have the same tree contents as the old ones (= identical tree hash)
+	origRestores := make(map[string]struct{})
+	for i, snapshotID := range snapshotIDs {
+		restoredir := filepath.Join(env.base, fmt.Sprintf("restore%d", i))
+		origRestores[restoredir] = struct{}{}
+		testRunRestore(t, env.gopts, restoredir, snapshotID)
+	}
+	for i, snapshotID := range copiedSnapshotIDs {
+		restoredir := filepath.Join(env2.base, fmt.Sprintf("restore%d", i))
+		testRunRestore(t, env2.gopts, restoredir, snapshotID)
+		foundMatch := false
+		for cmpdir := range origRestores {
+			diff := directoriesContentsDiff(restoredir, cmpdir)
+			if diff == "" {
+				delete(origRestores, cmpdir)
+				foundMatch = true
+			}
+		}
+
+		rtest.Assert(t, foundMatch, "found no counterpart for snapshot %v", snapshotID)
+	}
+
+	rtest.Assert(t, len(origRestores) == 0, "found not copied snapshots")
+}
+
+func TestCopyIncremental(t *testing.T) {
+	env, cleanup := withTestEnvironment(t)
+	defer cleanup()
+	env2, cleanup2 := withTestEnvironment(t)
+	defer cleanup2()
+
+	testSetupBackupData(t, env)
+	opts := BackupOptions{}
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9")}, opts, env.gopts)
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9", "2")}, opts, env.gopts)
+	testRunCheck(t, env.gopts)
+
+	testRunInit(t, env2.gopts)
+	testRunCopy(t, env.gopts, env2.gopts)
+
+	snapshotIDs := testRunList(t, "snapshots", env.gopts)
+	copiedSnapshotIDs := testRunList(t, "snapshots", env2.gopts)
+
+	// Check that the copies size seems reasonable
+	testRunCheck(t, env2.gopts)
+	rtest.Assert(t, len(snapshotIDs) == len(copiedSnapshotIDs), "expected %v snapshots, found %v",
+		len(snapshotIDs), len(copiedSnapshotIDs))
+
+	// check that no snapshots are copied, as there are no new ones
+	testRunCopy(t, env.gopts, env2.gopts)
+	testRunCheck(t, env2.gopts)
+	copiedSnapshotIDs = testRunList(t, "snapshots", env2.gopts)
+	rtest.Assert(t, len(snapshotIDs) == len(copiedSnapshotIDs), "still expected %v snapshots, found %v",
+		len(snapshotIDs), len(copiedSnapshotIDs))
+
+	// check that only new snapshots are copied
+	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9", "3")}, opts, env.gopts)
+	testRunCopy(t, env.gopts, env2.gopts)
+	testRunCheck(t, env2.gopts)
+	snapshotIDs = testRunList(t, "snapshots", env.gopts)
+	copiedSnapshotIDs = testRunList(t, "snapshots", env2.gopts)
+	rtest.Assert(t, len(snapshotIDs) == len(copiedSnapshotIDs), "still expected %v snapshots, found %v",
+		len(snapshotIDs), len(copiedSnapshotIDs))
+
+	// also test the reverse direction
+	testRunCopy(t, env2.gopts, env.gopts)
+	testRunCheck(t, env.gopts)
+	snapshotIDs = testRunList(t, "snapshots", env.gopts)
+	rtest.Assert(t, len(snapshotIDs) == len(copiedSnapshotIDs), "still expected %v snapshots, found %v",
+		len(copiedSnapshotIDs), len(snapshotIDs))
+}
+
 func testRunTag(t testing.TB, opts TagOptions, gopts GlobalOptions) {
 	rtest.OK(t, runTag(opts, gopts, []string{}))
 }
@@ -630,10 +723,7 @@ func TestTag(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	testRunInit(t, env.gopts)
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
+	testSetupBackupData(t, env)
 	testRunBackup(t, "", []string{env.testdata}, BackupOptions{}, env.gopts)
 	testRunCheck(t, env.gopts)
 	newest, _ := testRunSnapshots(t, env.gopts)
@@ -881,8 +971,8 @@ func TestRestore(t *testing.T) {
 	restoredir := filepath.Join(env.base, "restore")
 	testRunRestoreLatest(t, env.gopts, restoredir, nil, nil)
 
-	rtest.Assert(t, directoriesEqualContents(env.testdata, filepath.Join(restoredir, filepath.Base(env.testdata))),
-		"directories are not equal")
+	diff := directoriesContentsDiff(env.testdata, filepath.Join(restoredir, filepath.Base(env.testdata)))
+	rtest.Assert(t, diff == "", "directories are not equal %v", diff)
 }
 
 func TestRestoreLatest(t *testing.T) {
@@ -1033,10 +1123,7 @@ func TestFind(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	testRunInit(t, env.gopts)
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
+	datafile := testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	testRunBackup(t, "", []string{env.testdata}, opts, env.gopts)
@@ -1073,10 +1160,7 @@ func TestFindJSON(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	testRunInit(t, env.gopts)
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
-
+	datafile := testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	testRunBackup(t, "", []string{env.testdata}, opts, env.gopts)
@@ -1199,18 +1283,7 @@ func TestPrune(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	fd, err := os.Open(datafile)
-	if os.IsNotExist(errors.Cause(err)) {
-		t.Skipf("unable to find data file %q, skipping", datafile)
-		return
-	}
-	rtest.OK(t, err)
-	rtest.OK(t, fd.Close())
-
-	testRunInit(t, env.gopts)
-
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
+	testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	testRunBackup(t, "", []string{filepath.Join(env.testdata, "0", "0", "9")}, opts, env.gopts)
@@ -1317,9 +1390,9 @@ func TestHardLink(t *testing.T) {
 	for i, snapshotID := range snapshotIDs {
 		restoredir := filepath.Join(env.base, fmt.Sprintf("restore%d", i))
 		t.Logf("restoring snapshot %v to %v", snapshotID.Str(), restoredir)
-		testRunRestore(t, env.gopts, restoredir, snapshotIDs[0])
-		rtest.Assert(t, directoriesEqualContents(env.testdata, filepath.Join(restoredir, "testdata")),
-			"directories are not equal")
+		testRunRestore(t, env.gopts, restoredir, snapshotID)
+		diff := directoriesContentsDiff(env.testdata, filepath.Join(restoredir, "testdata"))
+		rtest.Assert(t, diff == "", "directories are not equal %v", diff)
 
 		linkResults := createFileSetPerHardlink(filepath.Join(restoredir, "testdata"))
 		rtest.Assert(t, linksEqual(linkTests, linkResults),
@@ -1385,18 +1458,7 @@ func TestQuietBackup(t *testing.T) {
 	env, cleanup := withTestEnvironment(t)
 	defer cleanup()
 
-	datafile := filepath.Join("testdata", "backup-data.tar.gz")
-	fd, err := os.Open(datafile)
-	if os.IsNotExist(errors.Cause(err)) {
-		t.Skipf("unable to find data file %q, skipping", datafile)
-		return
-	}
-	rtest.OK(t, err)
-	rtest.OK(t, fd.Close())
-
-	testRunInit(t, env.gopts)
-
-	rtest.SetupTarTestFixture(t, env.testdata, datafile)
+	testSetupBackupData(t, env)
 	opts := BackupOptions{}
 
 	env.gopts.Quiet = false

cmd/restic/main.go

@@ -54,7 +54,7 @@ directories in an encrypted repository stored on different backends.
 		if c.Name() == "version" {
 			return nil
 		}
-		pwd, err := resolvePassword(globalOptions)
+		pwd, err := resolvePassword(globalOptions, "RESTIC_PASSWORD")
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Resolving password failed: %v\n", err)
 			Exit(1)