wings/server/backup/backup_s3.go
2021-09-01 09:54:41 -06:00

266 lines
7.6 KiB
Go

package backup
import (
"archive/tar"
"compress/gzip"
"context"
"fmt"
"io"
"net/http"
"os"
"strconv"
"time"
"emperror.dev/errors"
"github.com/cenkalti/backoff/v4"
"github.com/pterodactyl/wings/server/filesystem"
"github.com/juju/ratelimit"
"github.com/pterodactyl/wings/config"
"github.com/pterodactyl/wings/remote"
)
type S3Backup struct {
Backup
}
var _ BackupInterface = (*S3Backup)(nil)
func NewS3(client remote.Client, uuid string, ignore string) *S3Backup {
return &S3Backup{
Backup{
client: client,
Uuid: uuid,
Ignore: ignore,
adapter: S3BackupAdapter,
},
}
}
// Remove removes a backup from the system.
func (s *S3Backup) Remove() error {
return os.Remove(s.Path())
}
// WithLogContext attaches additional context to the log output for this backup.
func (s *S3Backup) WithLogContext(c map[string]interface{}) {
s.logContext = c
}
// Generate creates a new backup on the disk, moves it into the S3 bucket via
// the provided presigned URL, and then deletes the backup from the disk.
func (s *S3Backup) Generate(ctx context.Context, basePath, ignore string) (*ArchiveDetails, error) {
defer s.Remove()
a := &filesystem.Archive{
BasePath: basePath,
Ignore: ignore,
}
s.log().WithField("path", s.Path()).Info("creating backup for server")
if err := a.Create(s.Path()); err != nil {
return nil, err
}
s.log().Info("created backup successfully")
rc, err := os.Open(s.Path())
if err != nil {
return nil, errors.Wrap(err, "backup: could not read archive from disk")
}
defer rc.Close()
if err := s.generateRemoteRequest(ctx, rc); err != nil {
return nil, err
}
ad, err := s.Details(ctx)
if err != nil {
return nil, errors.WrapIf(err, "backup: failed to get archive details after upload")
}
return ad, nil
}
// Restore will read from the provided reader assuming that it is a gzipped
// tar reader. When a file is encountered in the archive the callback function
// will be triggered. If the callback returns an error the entire process is
// stopped, otherwise this function will run until all files have been written.
//
// This restoration uses a workerpool to use up to the number of CPUs available
// on the machine when writing files to the disk.
func (s *S3Backup) Restore(ctx context.Context, r io.Reader, callback RestoreCallback) error {
reader := r
// Steal the logic we use for making backups which will be applied when restoring
// this specific backup. This allows us to prevent overloading the disk unintentionally.
if writeLimit := int64(config.Get().System.Backups.WriteLimit * 1024 * 1024); writeLimit > 0 {
reader = ratelimit.Reader(r, ratelimit.NewBucketWithRate(float64(writeLimit), writeLimit))
}
gr, err := gzip.NewReader(reader)
if err != nil {
return err
}
defer gr.Close()
tr := tar.NewReader(gr)
for {
select {
case <-ctx.Done():
return nil
default:
// Do nothing, fall through to the next block of code in this loop.
}
header, err := tr.Next()
if err != nil {
if err == io.EOF {
break
}
return err
}
if header.Typeflag == tar.TypeReg {
if err := callback(header.Name, tr, header.FileInfo().Mode(), header.AccessTime, header.ModTime); err != nil {
return err
}
}
}
return nil
}
// Generates the remote S3 request and begins the upload.
func (s *S3Backup) generateRemoteRequest(ctx context.Context, rc io.ReadCloser) error {
defer rc.Close()
s.log().Debug("attempting to get size of backup...")
size, err := s.Backup.Size()
if err != nil {
return err
}
s.log().WithField("size", size).Debug("got size of backup")
s.log().Debug("attempting to get S3 upload urls from Panel...")
urls, err := s.client.GetBackupRemoteUploadURLs(context.Background(), s.Backup.Uuid, size)
if err != nil {
return err
}
s.log().Debug("got S3 upload urls from the Panel")
s.log().WithField("parts", len(urls.Parts)).Info("attempting to upload backup to s3 endpoint...")
uploader := newS3FileUploader(rc)
for i, part := range urls.Parts {
// Get the size for the current part.
var partSize int64
if i+1 < len(urls.Parts) {
partSize = urls.PartSize
} else {
// This is the remaining size for the last part,
// there is not a minimum size limit for the last part.
partSize = size - (int64(i) * urls.PartSize)
}
// Attempt to upload the part.
if _, err := uploader.uploadPart(ctx, part, partSize); err != nil {
s.log().WithField("part_id", i+1).WithError(err).Warn("failed to upload part")
return err
}
s.log().WithField("part_id", i+1).Info("successfully uploaded backup part")
}
s.log().WithField("parts", len(urls.Parts)).Info("backup has been successfully uploaded")
return nil
}
type s3FileUploader struct {
io.ReadCloser
client *http.Client
}
// newS3FileUploader returns a new file uploader instance.
func newS3FileUploader(file io.ReadCloser) *s3FileUploader {
return &s3FileUploader{
ReadCloser: file,
// We purposefully use a super high timeout on this request since we need to upload
// a 5GB file. This assumes at worst a 10Mbps connection for uploading. While technically
// you could go slower we're targeting mostly hosted servers that should have 100Mbps
// connections anyways.
client: &http.Client{Timeout: time.Hour * 2},
}
}
// backoff returns a new expoential backoff implementation using a context that
// will also stop the backoff if it is canceled.
func (fu *s3FileUploader) backoff(ctx context.Context) backoff.BackOffContext {
b := backoff.NewExponentialBackOff()
b.Multiplier = 2
b.MaxElapsedTime = time.Minute
return backoff.WithContext(b, ctx)
}
// uploadPart attempts to upload a given S3 file part to the S3 system. If a
// 5xx error is returned from the endpoint this will continue with an exponential
// backoff to try and successfully upload the part.
//
// Once uploaded the ETag is returned to the caller.
func (fu *s3FileUploader) uploadPart(ctx context.Context, part string, size int64) (string, error) {
r, err := http.NewRequestWithContext(ctx, http.MethodPut, part, nil)
if err != nil {
return "", errors.Wrap(err, "backup: could not create request for S3")
}
r.ContentLength = size
r.Header.Add("Content-Length", strconv.Itoa(int(size)))
r.Header.Add("Content-Type", "application/x-gzip")
// Limit the reader to the size of the part.
r.Body = Reader{Reader: io.LimitReader(fu.ReadCloser, size)}
var etag string
err = backoff.Retry(func() error {
res, err := fu.client.Do(r)
if err != nil {
if errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled) {
return backoff.Permanent(err)
}
// Don't use a permanent error here, if there is a temporary resolution error with
// the URL due to DNS issues we want to keep re-trying.
return errors.Wrap(err, "backup: S3 HTTP request failed")
}
_ = res.Body.Close()
if res.StatusCode != http.StatusOK {
err := errors.New(fmt.Sprintf("backup: failed to put S3 object: [HTTP/%d] %s", res.StatusCode, res.Status))
// Only attempt a backoff retry if this error is because of a 5xx error from
// the S3 endpoint. Any 4xx error should be treated as an error that a retry
// would not fix.
if res.StatusCode >= http.StatusInternalServerError {
return err
}
return backoff.Permanent(err)
}
// Get the ETag from the uploaded part, this should be sent with the
// CompleteMultipartUpload request.
etag = res.Header.Get("ETag")
return nil
}, fu.backoff(ctx))
if err != nil {
if v, ok := err.(*backoff.PermanentError); ok {
return "", v.Unwrap()
}
return "", err
}
return etag, nil
}
// Reader provides a wrapper around an existing io.Reader
// but implements io.Closer in order to satisfy an io.ReadCloser.
type Reader struct {
io.Reader
}
func (Reader) Close() error {
return nil
}