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restic/cmd/restic/cmd_copy.go
Pauline Middelink 7048cc3e58 Add copy functionality
Add a copy command to copy snapshots between repositories. It allows the user
to specify a destination repository, password, password-file, password-command
or key-hint to supply the necessary details to open the destination repository.

You need to supply a list of snapshots to copy, snapshots which already exist
in the destination repository will be skipped.

Note, when using the network this becomes rather slow, as it needs to read the
blocks, decrypt them using the source key, then encrypt them again using the
destination key before finally writing them out to the destination repository.
2020-08-26 22:17:52 +02:00

204 lines
6.3 KiB
Go

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
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
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
}
for sn := range FindFilteredSnapshots(ctx, srcRepo, opts.Hosts, opts.Tags, opts.Paths, args) {
Verbosef("snapshot %s of %v at %s)\n", sn.ID().Str(), sn.Paths, sn.Time)
Verbosef(" copy started, this may take a while...\n")
if err := copyTree(ctx, srcRepo, dstRepo, *sn.Tree); err != nil {
return err
}
debug.Log("tree copied")
if err = dstRepo.Flush(ctx); err != nil {
return err
}
debug.Log("flushed packs")
err = dstRepo.SaveIndex(ctx)
if err != nil {
debug.Log("error saving index: %v", err)
return err
}
debug.Log("saved index")
// save snapshot
sn.Parent = nil // Parent does not have relevance in the new repo.
sn.Original = nil // Original does not have relevance in the new repo.
newID, err := dstRepo.SaveJSONUnpacked(ctx, restic.SnapshotFile, sn)
if err != nil {
return err
}
Verbosef("snapshot %s saved\n", newID.Str())
}
return nil
}
func copyTree(ctx context.Context, srcRepo, dstRepo restic.Repository, treeID restic.ID) error {
tree, err := srcRepo.LoadTree(ctx, treeID)
if err != nil {
return fmt.Errorf("LoadTree(%v) returned error %v", treeID.Str(), err)
}
// Do we already have this tree blob?
if !dstRepo.Index().Has(treeID, restic.TreeBlob) {
newTreeID, err := 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: keep only one (big) buffer around.
// 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 := copyTree(ctx, srcRepo, dstRepo, *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 dstRepo.Index().Has(blobID, restic.DataBlob) {
continue
}
debug.Log("Copying blob %s\n", blobID.Str())
size, found := srcRepo.LookupBlobSize(blobID, restic.DataBlob)
if !found {
return fmt.Errorf("LookupBlobSize(%v) failed", blobID)
}
buf := restic.NewBlobBuffer(int(size))
n, err := srcRepo.LoadBlob(ctx, restic.DataBlob, blobID, buf)
if err != nil {
return fmt.Errorf("LoadBlob(%v) returned error %v", blobID, err)
}
if n != len(buf) {
return fmt.Errorf("wrong number of bytes read, want %d, got %d", len(buf), n)
}
newBlobID, err := dstRepo.SaveBlob(ctx, restic.DataBlob, buf, blobID)
if err != nil {
return fmt.Errorf("SaveBlob(%v) returned error %v", blobID, err)
}
// Assurance only.
if newBlobID != blobID {
return fmt.Errorf("SaveBlob(%v) returned unexpected id %s", blobID.Str(), newBlobID.Str())
}
}
}
return nil
}