Send uploaded file

I use echo framework for building REST API.
I receive file via http request and i need to send it to the next API service by post request.
How i can do this without storing file?

I've tried this way, but it doesn't feel right, because i have an error in response "Could not parse content as FormData"

func (h *Handler) UploadFile(c echo.Context) error {
	formFile, err := c.FormFile("file")
	if err != nil {
		return err
	}

	file, err := formFile.Open()
	if err != nil {
		return err
	}
	defer file.Close()

	cid, err := h.s.Upload(context.Background(), file)
	if err != nil {
		return err
	}

	return c.String(http.StatusOK, "Ok")

}

func (s *Storage) Upload(ctx context.Context, file io.Reader) (cid.Cid, error) {
	req, err := http.NewRequest(http.MethodPost, s.config.endpoint+"/upload", file)
	if err != nil {
		return cid.Undef, err
	}
	req.Header.Set("accept", "application/json")
	req.Header.Set("Content-Type", "multipart/form-data")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", s.config.token))
	res, err := s.config.hc.Do(req)
	if err != nil {
		return cid.Undef, err
	}
	d := json.NewDecoder(res.Body)
	if res.StatusCode != 200 {
		return cid.Undef, fmt.Errorf("unexpected response status: %d", res.StatusCode)
	}
	var out struct {
		Cid string `json:"cid"`
	}
	err = d.Decode(&out)
	if err != nil {
		return cid.Undef, err
	}
	return cid.Parse(out.Cid)
}

Here is the solution.
Thanks Vlad Vladov.

func (s *Storage) Upload(ctx context.Context, file multipart.File, fileHeader *multipart.FileHeader) (cid.Cid, error) {
	rCtx, cancel := context.WithTimeout(ctx, 30*time.Second)
	defer cancel()

	buf := new(bytes.Buffer)
	writer := multipart.NewWriter(buf)

	part, err := writer.CreateFormFile("file", fileHeader.Filename)
	if err != nil {
		return cid.Undef, err
	}

	b, err := ioutil.ReadAll(file)

	if err != nil {
		return cid.Undef, err
	}

	part.Write(b)
	writer.Close()
	req, err := http.NewRequestWithContext(rCtx, http.MethodPost, s.config.endpoint+"/upload", buf)
	if err != nil {
		return cid.Undef, err
	}

	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", s.config.token))
	req.Header.Set("X-Client", "web3.storage/go")

	res, err := s.config.hc.Do(req)
	if err != nil {
		return cid.Undef, err
	}

	d := json.NewDecoder(res.Body)
	if res.StatusCode != 200 {
		var out responseError
		d.Decode(&out)
		log.Error(out)
		return cid.Undef, fmt.Errorf("unexpected response status: %d", res.StatusCode)
	}
	var out struct {
		Cid string `json:"cid"`
	}
	err = d.Decode(&out)
	if err != nil {
		return cid.Undef, err
	}
	return cid.Parse(out.Cid)
}