How to create folder or key on s3 using AWS SDK for Node.js?

I'm using AWS SDK for Node.js to create a folder or key on s3. I searched on google, but I got nothing. Does anybody know how can I create a folder under my bucket with AWS SDK for Node.js? and how can you check if this folder exists in your bucket already?

if you use console.aws.amazon.com, you can create a folder in your bucket easily. it seems I didn't figure it out how to create it with AWS SDK for Node.js?

Solution 1:

S3 is not your typical file system. It's an object store. It has buckets and objects. Buckets are used to store objects, and objects comprise data (basically a file) and metadata (information about the file). When compared to a traditional file system, it's more natural to think of an S3 bucket as a drive rather than as a folder.

You don't need to pre-create a folder structure in an S3 bucket. You can simply put an object with the key cars/ford/focus.png even if cars/ford/ does not exist.

It's valuable to understand what happens at the API level in this case:

• the putObject call will create an object at cars/ford/focus.png but it will not create anything representing the intermediate folder structure of cars/ or cars/ford/.

• the actual folder structure does not exist, but is implied through delimiter=/ when you call listObjects, returning folders in CommonPrefixes and files in Contents.

• you will not be able to test for the ford sub-folder using headObject because cars/ford/ does not actually exist (it is not an object). Instead you have 2 options to see if it (logically) exists:

1. call listObjects with prefix=cars/ford/ and find it in Contents
2. call listObjects with prefix=cars/, delimiter=/ and find it in CommonPrefixes

It is possible to create an S3 object that represents a folder, if you really want to. The AWS S3 console does this, for example. To create myfolder in a bucket named mybucket, you can issue a putObject call with bucket=mybucket, key=myfolder/, and size 0. Note the trailing forward slash.

Here's an example of creating a folder-like object using the awscli:

aws s3api put-object --bucket mybucket --key cars/ --content-length 0

In this case:

• the folder is actually a zero-sized object whose key ends in /. Note that if you leave off the trailing / then you will get a zero-sized object that appears to be a file rather than a folder.

• you are now able to test for the presence of cars/ in mybucket by issuing a headObject call with bucket=mybucket and key=cars/.

Finally, note that your folder delimiter can be anything you like, for example +, because it is simply part of the key and is not actually a folder separator (there are no folders). You can vary your folder delimiter from listObjects call to call if you like.

Solution 2:

The code from @user2837831 doesn't seem to work anymore, probably with the new version of javascript sdk. So I am adding here the version of code that I am using to create a folder inside a bucket using node.js. This works with the 2.1.31 sdk. What is important is the '/' at the end of the Key value in params - using that it thinks you are trying to create a folder and not a file.

var AWS = require('aws-sdk');
AWS.config.region = 'us-east-1';
var s3Client = new AWS.S3();

var params = { Bucket: 'your_bucket_goes_here', Key: 'folderInBucket/', ACL: 'public-read', Body:'body does not matter' };

s3Client.upload(params, function (err, data) {
if (err) {
    console.log("Error creating the folder: ", err);
    } else {
    console.log("Successfully created a folder on S3");

    }
});

Solution 3:

I find that we do not need an explicit directory creation call anymore.

Just the following works for me and automatically creates a directory hierarchy as I need.

var userFolder = 'your_bucket_name' + '/' + variable-with-dir-1-name + '/' + variable-with-dir-2-name;
// IMPORTANT : No trailing '/' at the end of the last directory name

AWS.config.region = 'us-east-1';

AWS.config.update({
    accessKeyId: 'YOUR_KEY_HERE',
    secretAccessKey: 'your_secret_access_key_here'
});

var bucket = new AWS.S3({
    params: {
        Bucket: userFolder
    }
});

var contentToPost = {
    Key: <<your_filename_here>>, 
    Body: <<your_file_here>>,
    ContentEncoding: 'base64',
    ContentType: <<your_file_content_type>>,
    ServerSideEncryption: 'AES256'
};

bucket.putObject(contentToPost, function (error, data) {

    if (error) {
        console.log("Error in posting Content [" + error + "]");
        return false;
    } /* end if error */
    else {
        console.log("Successfully posted Content");
    } /* end else error */
})
.on('httpUploadProgress',function (progress) {
    // Log Progress Information
    console.log(Math.round(progress.loaded / progress.total * 100) + '% done');
});

Solution 4:

This is really straightforward you can do it by using the following, just remember the trailing slash.

var AWS = require("aws-sdk");
var s3 = new AWS.S3();

var params = { 
  Bucket: "mybucket", 
  Key: "mykey/"
};

s3.putObject(params).promise();