How to specify upload directory in multer-S3 for AWS-S3 bucket?

Question

I am using express + multer-s3 to upload files to AWS S3 service.

Using the following code, I was able to upload the files to S3 Bucket but directly in the bucket.

I want them to be uploaded in a folder inside the bucket.

I was not able to find the option to do so.

Here is the code

AWS.config.loadFromPath("path-to-credentials.json");
var s3 = new AWS.S3();

var cloudStorage = multerS3({
    s3: s3,
    bucket: "sample_bucket_name",
    contentType: multerS3.AUTO_CONTENT_TYPE,
    metadata: function(request, file, ab_callback) {
        ab_callback(null, {fieldname: file.fieldname});
    },
    key: function(request, file, ab_callback) {
        var newFileName = Date.now() + "-" + file.originalname;
        ab_callback(null, newFileName);
    },
});
var upload = multer({
    storage: cloudStorage
});

router.post("/upload", upload.single('myFeildName'), function(request, response) {
    var file = request.file;
    console.log(request.file);
    response.send("aatman is awesome!");
});

Answer 1

S3 doesn't always have folders (see http://docs.aws.amazon.com/AmazonS3/latest/UG/FolderOperations.html). It will simulate folders by adding a strings separated by / to your filename.

e.g.

key: function(request, file, ab_callback) {
    var newFileName = Date.now() + "-" + file.originalname;
    var fullPath = 'firstpart/secondpart/'+ newFileName;
    ab_callback(null, fullPath);
},