Patrick Brandt patrickbrandt

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/

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

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

	# 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

	<!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);

	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);
	};

	#!/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