I thought I’d share the scripts I use to take a fresh Centos6 install and have it configured to work with a Chef server. Maybe its not as easy as when running in a virtualized environment, but it saves plenty of time. On the new node I run the setup_client.sh script which calls in the end client_gen.sh on the Chef server once everything is installed on the node. I left the version numbers for Ruby and Chef in the script so you know what versions I’ve tested this with. ...

This is a summary of a talk by Cliff Moon @moonpolysoft given at Strangeloop about building mixed Erlang and Scala systems with Scalang. Boundary does network analytics as a service. Their architecture uses a mixture of Erlang and Scala. Erlang is very very good at doing things like no down time deploys. We can have very low downtime on public facing parts of the system and we don’t even have to go down for deploys. ...

The following is NOT a tutorial for either Batman.js or Knockout.js. But, it is instead a sort of side-by-side comparison of the two for creating a user creation form that POSTs the new user’s data as JSON to the backend. The method of web development I’ve come to find the best is based on heavy frontend Javascript (though written in Coffeescript) communicating with a backend via a RESTful interface. This is appealing, because you are not cluttering the application logic with view related code. ...

This tutorial is brought to you by ErlangCamp 2011 (click here) - Boston, August 12th and 13th - It’s gonna be totally sweet! Main contributors: Torben Hoffmann, Raghav Karol, Eric Merritt The purpose of the short document is to help people who are familiar with unit testing understand how property based testing (PBT) differs, but also where the thinking is the same. This document focusses on the PBT tool ...

This tutorial is brought to you by ErlangCamp 2011 - Boston, August 12th and 13th - It’s gonna be totally sweet! It often occurs in coding that we need a library, a set of functionality. Often there are several algorithms that could provide this functionality. However, the code that uses it, either doesn’t care about the individual algorithm or wishes to delegate choosing that algorithm to some higher level. Lets take the concrete example of dictionaries. ...

I was thoroughly impressed with PubNub, a publish/subscribe service, when I first read their articles and played around with it some in Javascript. But obviously I need an Erlang API if I’m going to really use it! So I’ve created ePubNub. In the ePubNub README you’ll find information on some basic usage of the application. You don’t have to do anything more than use the epubnub.erl module to publish and subscribe (by either providing a PID to send messages to or a function handler to process each). ...

In my last post I showed the Webmachine backend to James Yu’s CloudEdit app in Backbone.js. What was left out was, where are the documents stored? Here I’ll show how this is done with CouchDB. And you can give the app a try at http://erlware.org:8080 First, a new Erlang app is needed that we’ll call ece_db. Three modules are implemented, one that starts the app by calling the supervisor’s start function, the supervisor itself that sets up a simple_one_for_one and the gen_server that handles the frontends requests for creating and modifying documents in CouchDB. ...

To experiment with using a pure client-side rendering talking to an Erlang backend I’ve taken James Yu’s CloudEdit tutorial an app written with Backbone.js and Rails and converted the backend to use Webmachine and CouchDB. You can see eCloudEdit in action here. The Backbone.js code is the same so to understand that please see James' post, here I’ll describe the Erlang backend. To begin with we setup two applications, one for handling the web interaction and a second for handling the database interaction. ...