internal reverse proxy does not rewrite correct content-Length header after decompressing body with gzip

[stanxing]

Here is code link:

	if r.StatusCode == http.StatusOK {
		var buf []byte
		if strings.Contains(r.Header.Get("Content-Encoding"), "gzip") {
			gr, err := gzip.NewReader(r.Body)
			if err != nil {
				return err
			}
			defer gr.Close()
			buf, err = ioutil.ReadAll(gr)
			if err != nil {
				return err
			}
			r.Header.Del("Content-Encoding")
		} else {
			buf, err = ioutil.ReadAll(r.Body)
			if err != nil {
				return err
			}
		}
		r.Body = ioutil.NopCloser(bytes.NewReader(buf))
		if buf != nil {
			file := filepath.Join(router.opts.DownloadRoot, r.Request.URL.Path)
			os.MkdirAll(path.Dir(file), os.ModePerm)
			err = renameio.WriteFile(file, buf, 0666)
			if err != nil {
				return err
			}
		}
	}

r.Body = ioutil.NopCloser(bytes.NewReader(buf)) reload the decompressed data into r.Body，causing the content-Length changed. I debugged and found that go server returned AbortHandlerError and client reported EOF error.

Maybe it is a solution to rewrite content-length header.

decompressedBodyLength := strconv.Itoa(len(buf))
r.Header.Set("Content-Length", decompressedBodyLength)

[oiooj]

@stanxing Could you help send a Pull Request?

[stanxing]

Sure, I am glad to contribute it.

[stanxing]

@oiooj #177 finished 👀

[oiooj]

Thanks @stanxing