gistfile1.txt

	var AWS = require("aws-sdk");
	AWS.config.update({
		accessKeyId: "",
		secretAccessKey: "",
		region: "us-west-2"
	});

	var s3 = new AWS.S3();
	var bucketName = "movieinfos3";

	exports.handler = function (event, context, callback) {
		//check if parameter is invalid
		if (event.movieId == null) {
			callback(null, "Invalid parameter");
		}
		//declare config for each movie
		var params = {
			Bucket: bucketName, /* required */
			Prefix: event.movieId
		};
		//declare config for getting signedUrl Image from S3
		var signedUrlParams = {
			Bucket: bucketName
		};
		var arrImageUrl = [];
		//get all of keys of images in S3 movie folder
		s3.listObjects(params, function (err, data) {
			if (err) console.log(err, err.stack); // an error occurred
		else {
		//foreach list key names to get signed Url
		data.Contents.forEach(function (obj) {
			signedUrlParams.Key = obj.Key;
			var url = s3.getSignedUrl("getObject", signedUrlParams);
			arrImageUrl.push(url);
		})
			callback(null, arrImageUrl);//return list signedUrl
		}});
	};