使用NodeJS Multer转换上传 [英] Transform upload with NodeJS Multer

问题描述

我目前正在为我的用户实施文件/图像上传服务.在上传到s3存储桶之前，我想先对这些图像进行转换(调整大小/优化).

I'm currently implementing a file/image upload service for my users. I want to transform these images (resize/optimize) before uploading to my s3 bucket.

我目前正在做什么:在前端使用多部分表单(我认为实际的实现在这里没有关系..)，在后端使用multer和multer-s3软件包.

What I'm currently doing: Using a multipart form on my frontend (I think the actual implementation doesn't matter here..) and the multer and multer-s3 packages on my backend.

在这里，我的实现简化为重要部分.

Here my implementation stripped down to the important parts.

// SETUP
var multer = require('multer');
var s3 = require('multer-s3');
var storage = s3({
    dirname: 'user/uploads',
    bucket: auth.aws.s3.bucket,
    secretAccessKey: auth.aws.s3.secretAccessKey,
    accessKeyId: auth.aws.s3.accessKeyId,
    region: auth.aws.s3.region,
    filename: function (req, file, cb) {
        cb(null, Date.now());
    }
});
var upload = multer({storage: storage}).single('img');

// ROUTE
module.exports = Router()
    .post('/', function (req, res, next) {
        upload(req, res, function (err) {
            if (err) {
                return res.status(401).json({err: '...'});
            }
            return res.json({err:null,url: '..'});
        });
    });

我要做什么:在上传图像之前先对其进行转换.我不确定是否需要在这里使用multer/busboy，还是可以使用NodeJS来做到这一点(因此，我已经标记了NodeJS并表示出来).

What I want to do: transform the image before uploading it. I'm not sure if I need to use multer/busboy here or I can just do it with NodeJS (thus I've tagged NodeJS and express as well).

所以我的问题是:在将上传到我的S3存储桶之前，我可以在哪里截取上传并对其进行转换?

So my question is: where can I intercept the upload and transform it before uploading it to my S3 bucket?

推荐答案

不确定您是否还在寻找答案，但我遇到了同样的问题.我决定扩展multer-s3软件包.

Not sure if you're still looking for an answer to this, but I had the same problem. I decided to extend the multer-s3 package.

我已经打开了对原始存储库的提取请求，但是到目前为止，您可以使用我的叉子.

I've opened a pull request to the original repository, but for now, you can use my fork.

以下是使用扩展版本的示例:

Here's an example of how to use the extended version:

  var upload = multer({
    storage: multerS3({
      s3: s3,
      bucket: 'some-bucket',
      shouldTransform: function (req, file, cb) {
        cb(null, /^image/i.test(file.mimetype))
      },
      transforms: [{
        id: 'original',
        key: function (req, file, cb) {
          cb(null, 'image-original.jpg')
        },
        transform: function (req, file, cb) {
          cb(null, sharp().jpg())
        }
      }, {
        id: 'thumbnail',
        key: function (req, file, cb) {
          cb(null, 'image-thumbnail.jpg')
        },
        transform: function (req, file, cb) {
          cb(null, sharp().resize(100, 100).jpg())
        }
      }]
    })
  })

编辑:现在，我的叉子也可以通过npm以multer-s3-transform的名称使用.

My fork is also now available via npm under the name multer-s3-transform.

这篇关于使用NodeJS Multer转换上传的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！