尝试在 node-js/express 中代理图像 - Trying to proxy an image in node-js/express

当我尝试通过 Express 访问它时，我收到一个损坏的图像链接：

app.get('/fileThumbnail', function(req, res) {
var url = proxiedURL +"?" + querystring.stringify(req.query);
logger.info('/fileThumbnail going to url', url);
request.get(url, function(err, response, img) {
    logger.info("response:", response.statusCode, response.headers['content-type']);
    if (!err && response.statusCode === 200) {
        res.writeHead(200, {
            'Content-Type': response.headers['content-type']
        });
        // response.pipe(res);  // not working
        res.writeHead(200, response.headers);
        res.end(img, 'binary');
    } else res.send("Error occurred:", err, "; status code: ", response.statusCode);
})
});

缩略图来自 PHP 服务器：

if (!$thumbnail) {
    $thumbnail = $_SERVER['DOCUMENT_ROOT'].'/images/spacer.gif';
}

// Write the thumbnail
header('Content-Type: '.image_type_to_mime_type(exif_imagetype($thumbnail)));
header('Content-length: '.filesize($thumbnail));
print file_get_contents($thumbnail,FILE_BINARY);

已经尝试了几种方法;响应标头如下：

Access-Control-Allow-Methods:GET,POST,PUT,DELETE,OPTIONS
access-control-allow-origin:*
cache-control:no-store, no-cache, must-revalidate, post-check=0, pre-check=0
connection:Keep-Alive
content-length:894
content-type:image/jpeg
date:Mon, 17 Nov 2014 22:13:24 GMT
expires:Thu, 19 Nov 1981 08:52:00 GMT
keep-alive:timeout=5, max=100
pragma:no-cache
server:Apache/2.2.15
X-Powered-By:Express

像往常一样，简单的解决方案是最好的。只需npm install request，然后像这样使用它：

var request = require('request');
app.get('/fileThumbnail', function(req, res) {
    var url = proxiedURL +"?" + querystring.stringify(req.query);
    logger.info('/fileThumbnail going to url', url); 
    request.get(url).pipe(res);
});

使用 pipe（）不适用于我的 Express 版本，但是这个实现确实如此。它代理http和https图像网址。

通话方式：

http://example.com/image?url=https%3A%2F%2Fwww.google.com%2Fimages%2Fbranding%2Fgooglelogo%2F2x%2Fgooglelogo_color_272x92dp.png

源：

var url         = require('url');
var http        = require('http');
var https       = require('https');
app.get('/image', function (req, res) {
    var parts = url.parse(req.url, true);
    var imageUrl = parts.query.url;
    parts = url.parse(imageUrl);
    var filename = parts.pathname.split("/").pop();
    var options = {
        port: (parts.protocol === "https:" ? 443 : 80),
        host: parts.hostname,
        method: 'GET',
        path: parts.path,
        accept: '*/*'
    };
    var request = (options.port === 443 ? https.request(options) : http.request(options));
    request.addListener('response', function (proxyResponse) {
        var offset = 0;
        var contentLength = parseInt(proxyResponse.headers["content-length"], 10);
        var body = new Buffer(contentLength);
        proxyResponse.setEncoding('binary');
        proxyResponse.addListener('data', function(chunk) {
            body.write(chunk, offset, "binary");
            offset += chunk.length;
        }); 
        proxyResponse.addListener('end', function() {
            res.contentType(filename);
            res.write(body);
            res.end();            
        });
    });
    request.end();
});

request现在已被弃用，我邀请您使用node-fetch

您可以使用以下代码：

const { fetch } = require('node-fetch');
app.get('/fileThumbnail', function (req, res) {
  var url = proxiedURL + '?' + querystring.stringify(req.query);
  logger.info('/fileThumbnail going to url', url);
  fetch(url).then((actual) => {
    actual.headers.forEach((v, n) => res.setHeader(n, v));
    actual.body.pipe(res);
  });
});