Reactive S3 File Upload

react-s3.js

/*

Hello, this is a first attempt to write a reactive app.
It should deploy a static website to AWS S3.
After creating the bucket, it should put the public bucket policy,
configure the bucket website and upload the files in parallel.

                putBucketPolicy
createBucket -> putBucketWebsite
                uploadFiles -> upload index.html
                            -> upload other.html
Here is my shot at it:                            
*/

var fs = require('fs')
var AWS = require('aws-sdk'); 
var df = require('dateformat');
var now  = new Date();
var nows = df(now,"yyyy-mm-dd-hh-MM-ss") 
var rx = require("rx")

var bucketName = "example-" + nows;
console.log('Starting Example '+bucketName);

var s3 = new AWS.S3();

//Create Bucket
var createBucket = rx.Observable.fromNodeCallback(s3.createBucket,s3);
var bucket = createBucket({Bucket: bucketName});

//Put Bucket Website
var putBucketWebsite = rx.Observable.fromNodeCallback(s3.putBucketWebsite,s3);
var website = putBucketWebsite({
	Bucket: bucketName,
	WebsiteConfiguration : {
		IndexDocument : {
			Suffix:"index.html"},
		ErrorDocument: {
			Key: "index.html"}
	}
});

//Make the bucket public
var putBucketPolicy = rx.Observable.fromNodeCallback(s3.putBucketPolicy,s3);
var publicPolicy = [
	'{',
	'  "Version":"2012-10-17",',
	'  "Statement":[{',
	'	 "Sid":"AddPerm",',
	'        "Effect":"Allow",',
	'	 "Principal": "*",',
	'      "Action":["s3:GetObject"],',
	'      "Resource":["arn:aws:s3:::'+bucketName+'/*"',
	'     ]',
	'    }',
	'  ]',
	'}'].join('')

var pub = putBucketPolicy({
		Bucket: bucketName,
		Policy: publicPolicy
	});

//File Uploads
var files = ["index.html","other.html"];
var readFile = rx.Observable.fromNodeCallback(fs.readFile,fs)
var uploadFile = rx.Observable.fromNodeCallback(s3.putObject,s3)
var uploadFiles =  files.map(function(fileName){
	return readFile(fileName).flatMap(function(stream){		
		return uploadFile({
			Bucket: bucketName,
			Key:fileName,
			Body: stream,
			ContentType:"text/html"
		});
	});
})

//Compose the parallel streams
/*
                utBucketPolicy
createBucket -> putBucketWebsite
                uploadFiles -> upload index.html
                            -> upload other.html
*/

var pllUploads = rx.Observable.forkJoin(uploadFiles)
var pllTasks = rx.Observable.forkJoin(pub,website,pllUploads)

var deploy = bucket.flatMap(pllTasks);

//Subscribes to deployment steps
var subscription = deploy.subscribe (
	function(x) {console.log(x)},
	function(e) {
		console.error("Deployment failed")
		throw e
	},
	function() {
		console.log("Deployment Completed!");
		console.log("curl http://"+bucketName+".s3-website-us-east-1.amazonaws.com/")
	}
)