A basic pipeable write stream which uploads to Amazon S3 using the multipart file upload API.

• You don't need to know the size of the stream prior to uploading, which works excellently for cases where you are creating files from dynamic content or incoming streams that you don't know the size of.
• Easy to use, clean piping mechanism.
• Uses the official Amazon SDK for Node.js
• You can provide options for the upload call directly to do things like set server side encryption, reduced redundancy storage, or access level on the object, which I found some other similar modules to be lacking.
• Emits "chunk" events which expose the amount of incoming data received by the writable stream versus the amount of data that has been uploaded via the multipart API so far, allowing you to create a progress bar if you need it.

• The multipart upload API does not accept chunks less than 5mb in size. So although this module emits "chunk" events which can be used to show progress, the progress is not very granular, as the chunk events are only emitted every 5 MB, which even on the fastest connections isn't very frequently. (Note: this could be fixed by abandoning the official API, and making direct requests to S3, and piping each 5mb chunk directly into the web request, allowing for much more granular progress reports.)
• Requires your S3 credentials each time you want to upload. This could be cleaned up to only require credentials once which would then be reused each time you create an upload stream.
• No tests at the moment.

npm install s3-upload-stream

	var Uploader = require('s3-upload-stream').Uploader,
		zlib       = require('zlib'),
		fs         = require('fs');

	var read = fs.createReadStream('./path/to/file.ext');
	var compress = zlib.createGzip();

	var UploadStreamObject = new Uploader(
		//Connection details.
		{
			"accessKeyId": "REDACTED",
			"secretAccessKey": "REDACTED",
			"region": "us-east-1"
		},
		//Upload destination details.
		{
			"Bucket": "your-bucket-name",
			"Key": "uploaded-file-name " + new Date()
		},
		function (err, uploadStream)
		{
			if(err)
				console.log(err, uploadStream);
			else
			{
				uploadStream.on('chunk', function (data) {
					console.log(data);
				});
				uploadStream.on('uploaded', function (data) {
					console.log(data);
				});

				//Pipe the file stream through Gzip compression and upload result to S3.
				read.pipe(compress).pipe(uploadStream);
			}
		}
	);