node.js - 从 Golang 后端流式传输文件到 Node 前端

Question

我已经在 Golang 上设置了后端(封装在 Gin gonic 框架中)，前端在 NodeJS 上运行(封装在 Express 框架中)。假设Express是向Golang后台请求一个文件，接收回Express并推送给客户端。

前端 Node :

var request = require('request');

router.get('/testfile', function (req, res, next) {

  // URL to Golang backend server
  var filepath = 'http://127.0.0.1:8000/testfile';

  request(filepath, function (error, response, body) {

    // This is incorrect, as it's just rendering the body to the client as text
    res.send(body);  

  })

});

后端 Golang:

r.GET("/testfile", func(c *gin.Context) {

    url := "http://upload.wikimedia.org/wikipedia/en/b/bc/Wiki.png"

    timeout := time.Duration(5) * time.Second
    transport := &http.Transport{
        ResponseHeaderTimeout: timeout,
        Dial: func(network, addr string) (net.Conn, error) {
            return net.DialTimeout(network, addr, timeout)
        },
        DisableKeepAlives: true,
    }
    client := &http.Client{
        Transport: transport,
    }
    resp, err := client.Get(url)
    if err != nil {
        fmt.Println(err)
    }
    defer resp.Body.Close()

    c.Writer.Header().Set("Content-Disposition", "attachment; filename=Wiki.png")
    c.Writer.Header().Set("Content-Type", c.Request.Header.Get("Content-Type"))
    c.Writer.Header().Set("Content-Length", c.Request.Header.Get("Content-Length"))

    //stream the body to the client without fully loading it into memory
    io.Copy(c.Writer, resp.Body)

})

我的问题是:我如何正确地从 Node 向 Golang 请求文件，并将其呈现回客户端，同时保持流式传输文件的可能性(如果有大文件)？

Answer 1

我没有具体使用过 request 库，但本质上您需要如下内容(根据 request 文档判断):

const request = require('request')

// ...

router.get('/my-route', async (req, res) => {
  const requestResponse = await request('...')
  const binaryFile = Buffer.from(requestResponse.body, 'binary')

  res.type(requestResponse.headers('content-type'))
  res.end(binaryFile)
})