Uploading large files via Zuul

Question

I've faced a problem uploading big files through zuul. I'm using apache-commons file upload(https://commons.apache.org/proper/commons-fileupload/) to stream large files as well as I use zuul on the front. In my Spring Boot application I have disabled upload provided by Spring to use the one from apache commons:

  spring:
      http:
          multipart:
              enabled: false

Controller looks like that:

public ResponseEntity insertFile(@PathVariable Long profileId, 
    HttpServletRequest request) throws Exception {
    ServletFileUpload upload = new ServletFileUpload();
    FileItemIterator uploadItemIterator = upload.getItemIterator(request);
    if (!uploadItemIterator.hasNext()) {
        throw new FileUploadException("FileItemIterator was empty"); 
    } 
    while (uploadItemIterator.hasNext()) {
        FileItemStream fileItemStream = uploadItemIterator.next();
        if (fileItemStream.isFormField()) {
            continue; 
        } 
       //do stuff 
    } 
    return new ResponseEntity(HttpStatus.OK);
} 

If I access my application directly(without zuul), file upload works as intended. However, if it's accessed through zuul, FileItemIterator doesn't have items to traverse and request finishes with error immediately(ERR_CONNECTION_RESET). For zuul I have also disabled multipart given by Spring. Otherwise, it works. However, the files are not streamed. They are loaded completely and only after I get inside the controller(regular Spring behavior). Is there a way to use apache-commons streaming options with zuul?

Answer 1

I've found a solution. It's basically described here:

http://cloud.spring.io/spring-cloud-static/spring-cloud.html#_uploading_files_through_zuul

What I did to make it work. Just step by step:

1. To bypass the Spring DispatcherServlet I changed the URL:

From: http://localhost:8081/MyService/file

To: http://localhost:8081/zuul/MyService/file

2. Preserved disabling of Spring multipart upload:

   spring:
       http:
           multipart:
               enabled: false
   

The following header is not required. Transfer-Encoding: chunked

I tried to upload a large file without that one and it was fine.