Patrick Brandt patrickbrandt

Socket.io integration between an Express and Angular app is a breeze. I'll outline the Express implementation first, then outline Angular integration.

Express + socket.io

Reference socket.io in layout.jade

npm install socket.io --save and then reference socket.io in your layout.jade file:

doctype html
html(ng-app="example")
  head
    title= title

AWS recently released Versioning and Aliases for Lambda Functions. I'm going to outline how I've taken advantage of this to provide environmentally-aware Lambda function configurations in Python.

AWS Lambda doesn't currently support environment variables, so 12-factor-style configuration isn't an option. I'll be using seprate config files for each environment.

Pregame

We're making two assumptions for this article:

I've already created an AWS Lambda function with the following aliases:
- Dev
- Test
- Staging
- Production

Links to live by

Networking

Fundamentals

TCP Summary (including three-way handshake description): https://condor.depaul.edu/jkristof/technotes/tcp.html
TCP Headers: http://www.omnisecu.com/tcpip/tcp-header.php
TCP full protocol: http://www.networksorcery.com/enp/protocol/tcp.htm

Network management on Linux

http://www.cyberciti.biz/faq/setting-up-an-network-interfaces-file/

	#!/bin/bash

	# This script must be run with root-level permissions

	# Install Compass
	yum install -y gcc g++ make automake autoconf ruby-devel
	gem update --system
	gem install compass

	# Install Node

	var sumEvenFib = function(number) {
	var _internalSumEvenFib = function(current, fib, num, sum) {
	return (num <= 1) ? sum : _internalSumEvenFib(fib, current + fib, --num, (!(fib % 2) ? sum + fib : sum));
	};
	return _internalSumEvenFib(1, 1, number, 0);
	};

	<!DOCTYPE html>
	<html>
	<head>
	<script type="text/javascript">
	if (!navigator.serviceWorker.controller) {
	navigator.serviceWorker.register('/sw.js', { scope: '.'}).then(function(registration) {
	console.log('ServiceWorker registration successful with scope: ', registration.scope);
	window.location.reload();
	}).catch(function(err) {
	console.log('ServiceWorker registration failed: ', err);

	# This is a "Managed Script" in Jenkins
	COMMIT=`aws lambda get-alias --region $AWS_REGION --function-name $FUNCTION_NAME --name $PUBLISH_FROM_ALIAS \| grep "Description" \| cut -d'"' -f4`
	VERSION=`aws lambda publish-version --region $AWS_REGION --function-name $FUNCTION_NAME --description $COMMIT \| grep "Version" \| cut -d'"' -f4`
	aws lambda update-alias --region $AWS_REGION --function-name $FUNCTION_NAME --function-version $VERSION --name $PUBLISH_TO_ALIAS --description $COMMIT

	angular.module('example')
	.controller('MainCtrl', ['connectivityService', function(connectivityService) {
	connectivityService.onReconnect(function(){
	console.log('back online');
	});
	connectivityService.onLostConnection(function(){
	console.log('lost connection');
	});
	connectivityService.start();
	}]);

	{
	"Version": "2012-10-17",
	"Statement": [
	{
	"Sid": "AllowUserToSeeBucketListInTheConsole",
	"Action": [
	"s3:ListAllMyBuckets",
	"s3:GetBucketLocation"
	],
	"Effect": "Allow",

	import json
	import os

	def ping(event, context):
	ip1 = event['headers']['X-Forwarded-For'].split(',')[0]
	ip2 = event['requestContext']['identity']['sourceIp']
	print('two different referring IP address parsing techniques ip1: %s and ip2: %s') % (ip1, ip2)

	referringIP = event['requestContext']['identity']['sourceIp']
	#TODO: use a comma-delimited string to store multiple IP address values in the environment variable