AWS S3 object listing
You can use the Prefix
in s3 API params. I am adding an example that i used in a project:
listBucketContent: ({ Bucket, Folder }) => new Promise((resolve, reject) => {
const params = { Bucket, Prefix: `${Folder}/` };
s3.listObjects(params, (err, objects) => {
if (err) {
reject(ERROR({ message: 'Error finding the bucket content', error: err }));
} else {
resolve(SUCCESS_DATA(objects));
}
});
})
Here Bucket
is the name of the bucket that contains a folder and Folder
is the name of the folder that you want to list files in.
It's working fine now using this code :
var AWS = require('aws-sdk');
AWS.config.update({accessKeyId: 'mykey', secretAccessKey: 'mysecret', region: 'myregion'});
var s3 = new AWS.S3();
var params = {
Bucket: 'mystore.in',
Delimiter: '/',
Prefix: 's/5469b2f5b4292d22522e84e0/ms.files/'
}
s3.listObjects(params, function (err, data) {
if(err)throw err;
console.log(data);
});
Folders are illusory, but S3 does provide a mechanism to emulate their existence.
If you set Delimiter
to /
then each tier of responses will also return a CommonPrefixes
array of the next tier of "folders," which you'll append to the prefix from this request, to retrieve the next tier.
If your Prefix
is a "folder," append a trailing slash. Otherwise, you'll make an unnecessary request, because the first request will return one common prefix. E.g., folder "foo" will return one common prefix "foo/".
I put up a little module which lists contents of a "folder" you give it:
s3ls({bucket: 'my-bucket-name'}).ls('/', console.log);
will print something like this:
{ files: [ 'funny-cat-gifs-001.gif' ],
folders: [ 'folder/', 'folder2/' ] }
And that
s3ls({bucket: 'my-bucket-name'}).ls('/folder', console.log);
will print
{ files: [ 'folder/cv.docx' ],
folders: [ 'folder/sub-folder/' ] }
UPD: The latest version supports async/await Promise interface:
const { files, folders } = await lister.ls("/my-folder/subfolder/");
And here is the s3ls.js
:
var _ = require('lodash');
var S3 = require('aws-sdk').S3;
module.exports = function (options) {
var bucket = options.bucket;
var s3 = new S3({apiVersion: '2006-03-01'});
return {
ls: function ls(path, callback) {
var prefix = _.trimStart(_.trimEnd(path, '/') + '/', '/');
var result = { files: [], folders: [] };
function s3ListCallback(error, data) {
if (error) return callback(error);
result.files = result.files.concat(_.map(data.Contents, 'Key'));
result.folders = result.folders.concat(_.map(data.CommonPrefixes, 'Prefix'));
if (data.IsTruncated) {
s3.listObjectsV2({
Bucket: bucket,
MaxKeys: 2147483647, // Maximum allowed by S3 API
Delimiter: '/',
Prefix: prefix,
ContinuationToken: data.NextContinuationToken
}, s3ListCallback)
} else {
callback(null, result);
}
}
s3.listObjectsV2({
Bucket: bucket,
MaxKeys: 2147483647, // Maximum allowed by S3 API
Delimiter: '/',
Prefix: prefix,
StartAfter: prefix // removes the folder name from the file listing
}, s3ListCallback)
}
};
};