Heroku-Ready S3 Signing Server

A simple, heroku-ready signing server for your S3 bucket. Built specifically for Cordova & Angular. Inspired by http://coenraets.org/blog/2013/09/how-to-upload-pictures-from-a-phonegap-app-to-amazon-s3/

Node & Express signing server to upload media to an AWS S3 bucket.

First perform an npm install.

Next create a .env file and define your constants:

AWS_ACCESS_KEY_ID=ASDWOJFIJDSFHAEXAMPLE
AWS_SECRET_ACCESS_KEY=5lkdfauDJUUAHFJSfjsdNKSjafajhsdjfEXAMPLE
S3_BUCKET=s3bucketname

Start your server with npm start.

Send a POST request with the following object to /sign-s3:

{
	"name": "your-file-name.ext"
}

The server will create credentials for your application that will expire in 5 minutes.

Use the response data to inform a POST request to your S3 bucket.

// Sample AngularJS Service
// Requires Cordova File Transfer

angular.module('myapp')

.service( 'UploadService', [ '$q', '$http', function( $q, $http ) {
	
	function s3Uploader( imageURI, fileName ) {
		var deferred = $q.defer();

		var mime = imageURI.substr( imageURI.length - 3 );

		var options = new FileUploadOptions();
		options.fileKey = 'file';
		options.fileName = fileName;
	  	options.mimeType = 'image/' + mime;
	  	options.chunkedMode = false;

		$http.post( 'https://localhost:3000/sign-s3', { 'name': fileName } ).then( function( res ) {
			var data = res.data;
			options.params = {
			"key": fileName,
			"AWSAccessKeyId": data.key,
			"acl": "public-read",
			"policy": data.policy,
			"signature": data.signature,
			"Content-Type": options.mimeType
	    	};
	  	var ft = new FileTransfer();
	  	ft.upload( imageURI, "https://" + data.bucket + ".s3.amazonaws.com", function() {
	  		var imgUrl = "https://" + data.bucket + ".s3.amazonaws.com" + fileName;
	  		deferred.resolve( imgUrl );
	  	}, function( err ) {
	  		deferred.reject( err );
	  	}, options );
	  });

	  return deferred.promise;
	}

	var service = {
		upload: s3Uploader
	};

	return service;

}]);