Files
tamabox/internal/cmd/backup_restore.go
T

438 lines
14 KiB
Go

// Copyright 2026 tamakyi. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package cmd
import (
"bytes"
"context"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/service/s3"
"github.com/aws/smithy-go"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
"github.com/urfave/cli/v2"
"github.com/tamakyi/TamaBox/internal/conf"
"github.com/tamakyi/TamaBox/internal/storage"
)
const maxImageManifestBytes = 64 << 20 // 64 MiB,足以容纳大量对象且避免恶意清单耗尽内存。
// RestoreImages 从 backup 生成的 images-manifest.json 和 images/ 恢复 R2 对象。
var RestoreImages = &cli.Command{
Name: "restore-images",
Usage: "Validate and restore backed-up images to R2",
Action: runRestoreImages,
Flags: []cli.Flag{
&cli.StringFlag{
Name: "input",
Required: true,
Usage: "Backup directory or images-manifest.json path",
},
&cli.BoolFlag{
Name: "dry-run",
Usage: "Validate local files and remote targets without writing objects",
},
&cli.BoolFlag{
Name: "yes",
Usage: "Confirm actual remote writes",
},
&cli.BoolFlag{
Name: "overwrite",
Usage: "Allow replacing objects that already exist",
},
&cli.StringFlag{
Name: "target-prefix",
Value: "",
Usage: "Prefix prepended to every restored key (for isolated drills)",
},
},
}
type restoreImagesOptions struct {
Input string
DryRun bool
Yes bool
Overwrite bool
TargetPrefix string
}
// restoreObjectStore 的 PutObject 是带重试的高层操作,便于离线 fake 精确断言零写入。
type restoreObjectStore interface {
HeadObject(context.Context, *s3.HeadObjectInput, ...func(*s3.Options)) (*s3.HeadObjectOutput, error)
PutObject(context.Context, *s3.PutObjectInput) error
}
type r2RestoreObjectStore struct {
client *s3.Client
}
func (s *r2RestoreObjectStore) HeadObject(ctx context.Context, input *s3.HeadObjectInput, options ...func(*s3.Options)) (*s3.HeadObjectOutput, error) {
return s.client.HeadObject(ctx, input, options...)
}
func (s *r2RestoreObjectStore) PutObject(ctx context.Context, input *s3.PutObjectInput) error {
// storage.PutObject 提供每次独立 60 秒超时、最多 3 次重试、Body 回绕和可取消退避。
return storage.PutObject(ctx, s.client, input)
}
type restorePlannedObject struct {
entry imageManifestEntry
sourcePath string
targetKey string
}
func runRestoreImages(ctx *cli.Context) error {
opts := restoreImagesOptions{
Input: ctx.String("input"),
DryRun: ctx.Bool("dry-run"),
Yes: ctx.Bool("yes"),
Overwrite: ctx.Bool("overwrite"),
TargetPrefix: ctx.String("target-prefix"),
}
if opts.Input == "" {
return errors.New("--input must not be empty")
}
if !opts.DryRun && !opts.Yes {
return errors.New("actual restore writes require --yes (or use --dry-run)")
}
if err := conf.Init(); err != nil {
return errors.Wrap(err, "load configuration")
}
client, err := backupS3Client(ctx.Context)
if err != nil {
return errors.Wrap(err, "get R2 client for image restore")
}
return restoreImagesWithStore(ctx.Context, &r2RestoreObjectStore{client: client}, conf.Upload.ImageBucket, opts)
}
func restoreImagesWithStore(ctx context.Context, store restoreObjectStore, bucket string, opts restoreImagesOptions) error {
if opts.Input == "" {
return errors.New("restore input must not be empty")
}
if !opts.DryRun && !opts.Yes {
return errors.New("actual restore writes require --yes (or use --dry-run)")
}
manifestPath, imageDir, err := resolveRestoreInput(opts.Input)
if err != nil {
return err
}
entries, err := readImageManifest(manifestPath)
if err != nil {
return err
}
// 关键安全顺序:先验证所有 manifest 条目和全部本地文件,再做任何 Head/Put。
// 因此重复 key、非法 hash/size、缺文件、篡改或 symlink 都不会造成部分上传。
objects := make([]restorePlannedObject, 0, len(entries))
for _, entry := range entries {
targetKey, err := restoreTargetKey(opts.TargetPrefix, entry.Key)
if err != nil {
return err
}
sourcePath, err := localImagePath(imageDir, entry.Key)
if err != nil {
return err
}
if err := validateRestoreLocalFile(imageDir, sourcePath, entry); err != nil {
return err
}
objects = append(objects, restorePlannedObject{
entry: entry,
sourcePath: sourcePath,
targetKey: targetKey,
})
}
// 默认先 Head 所有目标。任何目标已存在都会在 Put 循环开始前失败,保证零 Put。
if !opts.Overwrite {
for _, object := range objects {
headCtx, cancel := context.WithTimeout(ctx, imageObjectAttemptTimeout)
_, err := store.HeadObject(headCtx, &s3.HeadObjectInput{
Bucket: aws.String(bucket),
Key: aws.String(object.targetKey),
})
cancel()
if err == nil {
return errors.Errorf("restore target %q already exists; no objects were uploaded (use --overwrite to replace)", object.targetKey)
}
if !isS3ObjectNotFound(err) {
return errors.Wrapf(err, "check restore target %q; no objects were uploaded", object.targetKey)
}
}
}
if opts.DryRun {
logrus.WithFields(logrus.Fields{
"objects": len(objects),
"prefix": opts.TargetPrefix,
}).Info("图片恢复演练完成,未写入对象")
return nil
}
succeeded := 0
for _, object := range objects {
file, err := openRestoreFileForPut(object.sourcePath, object.entry.Size)
if err != nil {
return errors.Wrapf(err, "open validated restore file for %q after %d successful uploads; restore is not transactional", object.entry.Key, succeeded)
}
input := &s3.PutObjectInput{
Bucket: aws.String(bucket),
Key: aws.String(object.targetKey),
Body: file,
ContentLength: aws.Int64(object.entry.Size),
ContentType: nonEmptyStringPointer(object.entry.ContentType),
CacheControl: nonEmptyStringPointer(object.entry.CacheControl),
}
putErr := store.PutObject(ctx, input)
closeErr := file.Close()
if putErr != nil {
return errors.Wrapf(putErr, "restore object %q to %q failed after %d successful uploads; restore is not transactional", object.entry.Key, object.targetKey, succeeded)
}
if closeErr != nil {
return errors.Wrapf(closeErr, "close restored file %q (remote object was uploaded); restore is not transactional", object.sourcePath)
}
succeeded++
}
logrus.WithFields(logrus.Fields{
"objects": succeeded,
"prefix": opts.TargetPrefix,
}).Info("图片恢复完成")
return nil
}
func resolveRestoreInput(input string) (manifestPath, imageDir string, err error) {
info, err := os.Lstat(input)
if err != nil {
return "", "", errors.Wrapf(err, "inspect restore input %q", input)
}
if info.Mode()&os.ModeSymlink != 0 {
return "", "", errors.Errorf("restore input %q must not be a symlink", input)
}
manifestPath = input
if info.IsDir() {
manifestPath = filepath.Join(input, "images-manifest.json")
} else if !info.Mode().IsRegular() {
return "", "", errors.Errorf("restore input %q is neither a directory nor a regular manifest file", input)
}
return manifestPath, filepath.Join(filepath.Dir(manifestPath), "images"), nil
}
func readImageManifest(manifestPath string) ([]imageManifestEntry, error) {
info, err := os.Lstat(manifestPath)
if err != nil {
return nil, errors.Wrapf(err, "inspect image manifest %q", manifestPath)
}
if info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular() {
return nil, errors.Errorf("image manifest %q must be a regular non-symlink file", manifestPath)
}
if info.Size() > maxImageManifestBytes {
return nil, errors.Errorf("image manifest %q exceeds the %d-byte limit", manifestPath, maxImageManifestBytes)
}
file, err := os.Open(manifestPath)
if err != nil {
return nil, errors.Wrapf(err, "open image manifest %q", manifestPath)
}
data, readErr := io.ReadAll(io.LimitReader(file, maxImageManifestBytes+1))
closeErr := file.Close()
if readErr != nil {
return nil, errors.Wrap(readErr, "read image manifest")
}
if closeErr != nil {
return nil, errors.Wrap(closeErr, "close image manifest")
}
if len(data) > maxImageManifestBytes {
return nil, errors.Errorf("image manifest %q exceeds the %d-byte limit", manifestPath, maxImageManifestBytes)
}
decoder := json.NewDecoder(bytes.NewReader(data))
var entries []imageManifestEntry
if err := decoder.Decode(&entries); err != nil {
return nil, errors.Wrap(err, "decode image manifest")
}
if entries == nil {
return nil, errors.New("image manifest must be a JSON array, not null")
}
var trailing json.RawMessage
if err := decoder.Decode(&trailing); err != io.EOF {
if err == nil {
return nil, errors.New("image manifest contains trailing JSON")
}
return nil, errors.Wrap(err, "image manifest contains trailing data")
}
seen := make(map[string]struct{}, len(entries))
for index := range entries {
entry := &entries[index]
if err := validateObjectKey(entry.Key); err != nil {
return nil, errors.Wrapf(err, "invalid manifest entry %d", index)
}
if _, exists := seen[entry.Key]; exists {
return nil, errors.Errorf("image manifest contains duplicate key %q", entry.Key)
}
seen[entry.Key] = struct{}{}
if entry.Size < 0 {
return nil, errors.Errorf("manifest entry %q has negative size %d", entry.Key, entry.Size)
}
decodedHash, err := hex.DecodeString(entry.SHA256)
if err != nil || len(decodedHash) != sha256.Size {
return nil, errors.Errorf("manifest entry %q has invalid SHA-256 %q", entry.Key, entry.SHA256)
}
entry.SHA256 = strings.ToLower(entry.SHA256)
}
return entries, nil
}
func restoreTargetKey(prefix, key string) (string, error) {
if prefix != "" && !strings.HasSuffix(prefix, "/") {
prefix += "/"
}
target := prefix + key
if err := validateObjectKey(target); err != nil {
return "", errors.Wrapf(err, "invalid restore target for source key %q", key)
}
return target, nil
}
func validateRestoreLocalFile(imageDir, sourcePath string, entry imageManifestEntry) error {
root, err := filepath.Abs(imageDir)
if err != nil {
return err
}
if err := validateRestoreDirectoryChain(root, filepath.Dir(sourcePath)); err != nil {
return err
}
info, err := os.Lstat(sourcePath)
if err != nil {
return errors.Wrapf(err, "inspect local image for %q", entry.Key)
}
if info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular() {
return errors.Errorf("local image for %q must be a regular non-symlink file", entry.Key)
}
if info.Size() != entry.Size {
return errors.Errorf("local image size mismatch for %q: manifest=%d actual=%d", entry.Key, entry.Size, info.Size())
}
file, err := os.Open(sourcePath)
if err != nil {
return errors.Wrapf(err, "open local image for %q", entry.Key)
}
openedInfo, statErr := file.Stat()
if statErr != nil {
_ = file.Close()
return errors.Wrapf(statErr, "stat opened local image for %q", entry.Key)
}
if !openedInfo.Mode().IsRegular() || openedInfo.Size() != entry.Size {
_ = file.Close()
return errors.Errorf("opened local image for %q is not the expected regular file", entry.Key)
}
hash := sha256.New()
_, hashErr := io.Copy(hash, file)
closeErr := file.Close()
if hashErr != nil {
return errors.Wrapf(hashErr, "hash local image for %q", entry.Key)
}
if closeErr != nil {
return errors.Wrapf(closeErr, "close local image for %q", entry.Key)
}
actualHash := hex.EncodeToString(hash.Sum(nil))
if actualHash != entry.SHA256 {
return errors.Errorf("local image SHA-256 mismatch for %q: manifest=%s actual=%s", entry.Key, entry.SHA256, actualHash)
}
return nil
}
func validateRestoreDirectoryChain(root, parent string) error {
rootInfo, err := os.Lstat(root)
if err != nil {
return errors.Wrapf(err, "inspect restore images directory %q", root)
}
if rootInfo.Mode()&os.ModeSymlink != 0 || !rootInfo.IsDir() {
return errors.Errorf("restore images path %q must be a real directory", root)
}
rel, err := filepath.Rel(root, parent)
if err != nil || !pathWithinDirectory(root, parent) {
return errors.Errorf("restore file parent %q escapes images directory", parent)
}
if rel == "." {
return nil
}
current := root
for _, segment := range strings.Split(rel, string(filepath.Separator)) {
current = filepath.Join(current, segment)
info, err := os.Lstat(current)
if err != nil {
return errors.Wrapf(err, "inspect restore parent directory %q", current)
}
if info.Mode()&os.ModeSymlink != 0 || !info.IsDir() {
return errors.Errorf("restore parent %q must be a real directory", current)
}
}
return nil
}
func openRestoreFileForPut(sourcePath string, expectedSize int64) (*os.File, error) {
info, err := os.Lstat(sourcePath)
if err != nil {
return nil, err
}
if info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular() || info.Size() != expectedSize {
return nil, fmt.Errorf("local file %q changed after validation", sourcePath)
}
file, err := os.Open(sourcePath)
if err != nil {
return nil, err
}
openedInfo, err := file.Stat()
if err != nil {
_ = file.Close()
return nil, err
}
if !openedInfo.Mode().IsRegular() || openedInfo.Size() != expectedSize {
_ = file.Close()
return nil, fmt.Errorf("local file %q changed after validation", sourcePath)
}
return file, nil
}
func isS3ObjectNotFound(err error) bool {
if err == nil {
return false
}
var statusErr interface{ HTTPStatusCode() int }
if errors.As(err, &statusErr) && statusErr.HTTPStatusCode() == 404 {
return true
}
var apiErr smithy.APIError
if errors.As(err, &apiErr) {
switch apiErr.ErrorCode() {
case "NotFound", "NoSuchKey", "404":
return true
}
}
return false
}
func nonEmptyStringPointer(value string) *string {
if value == "" {
return nil
}
return aws.String(value)
}