Method handleDownloadError

handlers/processing/request_methods.go:82–124

handleDownloadError replaces the image data with fallback image if needed

(
	err errctx.Error,
)

// handleDownloadError replaces the image data with fallback image if needed
func (r *request) handleDownloadError(
	err errctx.Error,
) (imagedata.ImageData, int, errctx.Error) {
	// If there is no fallback image configured, just return the error
	data, headers := r.getFallbackImage()
	if data == nil {
		return nil, 0, err
	}

	// Just send error
	r.Monitoring().SendError(r.req.Context(), handlers.ErrCategoryDownload, err)

	// We didn't return, so we have to report error
	if err.ShouldReport() {
		r.ErrorReporter().Report(err, r.req)
	}

	//nolint:gosec
	slog.Warn(
		"Could not load image. Using fallback image",
		"request_id", r.reqID,
		"image_url", r.imageURL,
		"error", err.Error(),
	)

	var statusCode int

	// Set status code if needed
	if r.config.FallbackImageHTTPCode > 0 {
		statusCode = r.config.FallbackImageHTTPCode
	} else {
		statusCode = err.StatusCode()
	}

	// Fallback image should have exact FallbackImageTTL lifetime
	headers.Del(httpheaders.Expires)
	headers.Del(httpheaders.LastModified)

	r.rw.SetOriginHeaders(headers)
	r.rw.SetIsFallbackImage()

	return data, statusCode, nil
}

// getFallbackImage returns fallback image if any
func (r *request) getFallbackImage() (imagedata.ImageData, http.Header) {