通过http在两个node.js服务器之间传输文件 [英] transfer files between two node.js servers over http

问题描述

我有两个node.js/express服务器，它们通过http相互通信. 服务器A 还可与浏览器通信，并可以处理文件上传请求.当文件上传到服务器A 时，我想按原样将其传输到服务器B 进行进一步处理.最好的方法是什么?最好与 request-promise 模块配合使用两台服务器之间的通信.

I have two node.js/express servers that communicate with each other with http. server A is also communicates with the browser and can handle file upload requests. When file is uploaded to server A i want to transfer it as is to server B for further processing. what is the best way to do so? preferably with request-promise module which is what i'm using for communication between the two servers.

到目前为止，这是我得到的，但是我无法在服务器之间传输文件，文件已成功上传到服务器A ，并且在将文件发送到，但服务器B无法将请求识别为文件.我在这里想念什么?

This is what i got so far, but i am unable to transfer the file between the servers, the file is uploaded successfully to server A, and there is no Error while sending it to server B, but server B is doesn't recognise the request as file. what am i missing here?

服务器A路由:

'use strict';

// Routes

 const express = require('express');
 const router = express.Router();
 const multer = require('multer');
 const upload = multer();

 const uploadController = require('./controllers/file/upload');

 router.post('/upload',upload.single('file'),uploadController); 

 module.exports = router;

服务器A uploadController:

'use strict';

const RP = require('request-promise');

module.exports = (req, res) => {

  const body = req.body;

  if(req.file) {

    const file = req.file;

    RP('http://serverB.net/process', { 
      method: 'POST',
      formData: {file_buffer: file.buffer},
      body: body
    })
    .then((response) => {
      return res.status(200).send(response);
    })
    .catch((e) => {
      return res.status(500).send(e.message);
    })
  }
  else {
     return res.status(500).send('unable to upload file');
  }
};

服务器B路由:

'use strict';

// Routes

 const express = require('express');
 const router = express.Router();
 const multer = require('multer');
 const process = multer();

 const processFile = require('./controllers/file/processFile');

 router.post('/process', process.single('file'), processFile); 

 module.exports = router;

服务器B的进程文件:

在这里我想处理服务器A 中的文件，但req.file是undefined

here i want to process the file from Server A but req.file is undefined

'use strict';

module.exports = (req, res) => {

  if(req.file) {
  // here i want to do something with the file.
  }

};

推荐答案

router.post('/process', process.single('file'), processFile);

此行，特别是process.single('file')，告诉multer查找将包含实际文件数据的字段file.但是，在您的请求中，您永远不会为file指定值.在您的请求中将名称file_buffer更改为仅file.或将您的process.single()更改为process.single('file_buffer')

This line, specifically process.single('file') tells multer to look for a field file which will contain the actual file data. However, in your request you never specify a value for file. Change the name file_buffer to just file in your request. Or change your process.single() to process.single('file_buffer')

RP('http://serverB.net/process', { 
  method: 'POST',
  formData: {
    file: file.buffer,
    body: body
  }
})
.then((response) => {
  return res.status(200).send(response);
})
.catch((e) => {
  return res.status(500).send(e.message);
})

现在在服务器B上的processFile内，您应该看到一个req.body字段，其中包含body字段，该字段包含在请求中传递的整个正文，并且现在应该有一个req.file字段，其中包含了multer文件对象.

Now on Server B, inside processFile you should see a req.body with a field body that contains your entire body passed in your request and you should have a req.file now that contains your multer file object.

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