readandupload.js

		function newReadAndUpload(){

			// Compute hash
			var filename = path.join(__dirname, '/input.csv.gz');
			return hash(filename).then(hash=>{
				console.log("hash: " + hash);

				// Generated signed url


				return getSignedUrl(hash).then(signedURL=>{
					console.log("Signed URL: "  + signedURL);

					// Open file
					var stat      = fs2.stat(filename);
					var stream    = fs2.createReadStream(filename);
					console.log(stat);
					// Upload
					var urlOpts = url.parse(signedURL);

					var req = https.request({
					  method:     'PUT',
					  host:       urlOpts.host,
					  path:       urlOpts.path,
					  headers: {
					    'content-type':     'application/x-tar',
					    //'content-length':   stat.size,
					    'content-encoding': 'gzip',
					    'cache-control':    'public, no-transform',
					    'content-md5':      hash
					  }
					});

					// Pipe stream
					stream.pipe(req);
					return res().then(res =>{
						// Print status code
						console.log("Response Code: " + res.statusCode);

						// Discard response text
						res.resume();
					}).catch(err =>{
						return {status: false, code: 500, data: err};
					});
	
				}).catch(err =>{
					return {status: false, code: 500, data: err};
				});
			}).catch(err =>{
				return {status: false, code: 500, data: err};
			})


		}

		function hash(filename){
			var hash = new Promise((accept, reject) => {
			  var md5 = crypto.createHash('md5');
			  var stream = fs2.createReadStream(filename);
			  stream.on('data', d => md5.update(d));
			  stream.on('end', () => accept(md5.digest('base64')));
			  stream.on('error', reject);
			});
			return hash;
		}

		function res(){
			var res = new Promise((accept, reject) => {
			  req.on('response', accept);
			  req.on('error', reject);
			  req.setTimeout(5 * 60 * 1000, reject);
			});
			return res;
		}

		function getSignedUrl(hash){
			var signedURL  = new Promise((accept, reject) => {
			var s3 = new aws.S3();
			  s3.getSignedUrl('putObject', {
			    Bucket:       'itgdata',
			    Key:          'datadump/" + title + ".gz',
			    ContentType:  'application/x-tar',
			    Expires:      15 * 60, // URL expiration
			    ContentMD5:   hash,
			    Metadata: {
			      "content-sha256":  "Hello World2"
			    }
			  }, (err, url) => err ? reject(err) : accept(url));
			});
			return signedURL ;
		}