Our Blog

Feature Isolation with Mike Farmer

By Brian Buchalter
October 9, 2012

My brilliant co-worker Mike Farmer gave a presentation today talking about a development strategy he calls “Feature Isolation.” It involves developing new features on the fringe of your application, isolating it from the complexity of existing code. This allows greater focus on ensuring that your feature is well designed from an object-oriented perspective and that you don’t build more than you need.

In order to truly isolate the feature, Mike put together some cucumber tools to allow you to run cucumber without Rails and to create what he calls a “FastModel”. The models are fast for two reasons. First, you don’t need to load ActiveRecord to get functionality like specifying field names, specifying relationships, or emulating saving records. Second, it let’s you to sketch out a design for your class while the cost of change is very very low.

An Example: Product Variants

Here’s an example of a tight little feature and step set for showing shoppers a comparison of product variants.

Feature: As a shopper, I want to compare the variants of a product

  Background:
    Given there is a product named "Product A"
    And it has some …

Piggybak: The Roadmap

By Steph Skardal
October 8, 2012

Over the last couple of weeks, a few of us at End Point have had some discussion about the future direction of Piggybak. Piggybak is an open source mountable ecommerce framework written in Ruby on Rails supported and developed by End Point. It introduces core ecommerce functionality into a Rails application, but is intended to allow the mounted Rails application to maintain control over some architecture elements.

Pros of Piggybak

Until now, the advantage of Piggybak is that it’s a fairly lightweight approach. It leverages the power of RailsAdmin rather than creating it’s own admin. It allows the mounted Rails application to make decisions on what types of items are sellable and how these items are found (i.e. product finding methods, SSL configuration). Piggybak also has streamlined integration of ActiveMerchant, which immediately provides support of over 40 popular payment gateways. Piggybak has a cookie-based cart and an AJAX-driven one-page checkout.

Cons of Piggybak Approach

Because Piggybak has a lightweight approach, the major disadvantage is that it cannot compete with existing ecommerce frameworks as an out of the box solution with a full ecommerce feature set. …

The Real Cost of Data Roundtrip

By Szymon Lipiński
October 3, 2012

Sometimes you need to perform some heavy database operations. I don’t know why very often programmers are afraid of using databases for that. They usually have some fancy ORM which performs all the operations, and the only way to change the data is to make some SELECT * from a table, create a bunch of unneeded objects, change one field, convert those changed objects into queries and send that to the database.

Have you ever thought about the cost of the roundtrip of data? The cost of getting all the data from database just to send changed data into the database? Why do that if there would be much faster way of achieving the same results?

Imagine that you have quite a heavy operation. Let’s make something which normally databases cannot do, some more complicated operation. Many programmers just don’t know that there is any other way than writing this in the application code. Let’s change all the HTML entities into real characters.

The HTML entities are a way of writing many different characters in HTML. This way you can write for instance the Euro currency sign “€” in HTML even if you don’t have it on your keyboard. You just have to write € …

Setting user ownership of nginx and Passenger processes

By Brian Buchalter
October 2, 2012

Do this now on all your production Rails app servers:

ps ux | grep Rails

The first column in the results of that command show which user runs your Rails and Passenger processes. If this is a privileged user (sudoer, or worse yet password-less sudoer), then this article is for you.

Assumptions Check

There are several different strategies for modifying which user your Rails app runs as. By default the owner of config/environment.rb is the user which Passenger will run your application as. For some, simply changing the ownership of this file is sufficient, but in some cases, we may want to force Passenger to always use a particular user.

This article assumes you are running nginx compiled with Passenger support and that you have configured an unprivileged user named rails-app. This configuration has been tested with nginx version 0.7.67 and Passenger version 2.2.15. (Dated I know, but now that you can’t find the docs for these old versions, this article is extra helpful.)

Modifying nginx.conf

The changes required in nginx are very straight forward.

# Added in the main, top-level section
user rails-app;

# Added in the appropriate http section among your other Passenger related …

Ubuntu Dual Monitor Setup on Dell XPS

By Steph Skardal
October 1, 2012

Over the weekend, I received a new desktop (Dell XPS 8500 with NVIDIA graphics card) and troubleshot dual monitor setup on Ubuntu. Because I spent quite a while googling for results, I thought I’d write up a quick summary of what did and didn’t work.

One monitor was connected via HDMI and the other through DVI (with a VGA to DVI adaptor provided with the computer). When I started up the computer in Windows, both monitors were recognized immediately. Besides configuring the positioning of the monitors, Windows was good to go. But when I installed Ubuntu, the DVI/VGA monitor was recognized with incorrect resolution and the monitor connected via HDMI was not recognized at all. I tried switching the unrecognized monitor to a VGA/DVI connection, and it worked great by itself, so I concluded that it wasn’t an issue with a driver for the HDMI-connected monitor.

Many of the Google results I came across pointed to troubleshooting with xrandr, but any xrandr commands produced a “Failed to get size of gamma for output default.” error and any progress beyond that was shut down. Another set of Google results pointed to using “nvidia-detector”, but there …

Defense in Depth

By Zed Jensen
September 28, 2012

“Defense in depth” is a way to build security systems so that when one layer of defense fails, there is another to take its place. If breaking in is hard enough for an attacker, it’s likely that they’ll abandon their assault, deciding it’s not worth the effort. Making the various layers different types of defense also makes it harder to get in, so that an attacker is less likely to get through all the layers. It can also keep one mistake from causing total security failure.

For example, if you have an office with one door and leave it unlocked by accident, then anyone can just walk in. However, if you have an office building with a main door, then a lobby and hallways, and then additional inner locked doors, then the chance of accidentally leaving both unlocked is small. If you accidentally leave the inner door open or unlocked, someone can only get into the office if they first get through the outer door.

Another example of defense in depth is making and maintaining offsite computer backups. The chance of an office being destroyed and all your data with it is low, but not zero. If you maintain offsite backups, then your losses in a catastrophe are reduced.

Another way to decrease …

Test Web Sites with Internet Explorer for Free

By Greg Davidson
September 26, 2012

Browser Testing

While many Web Developers prefer to build sites and web applications with browsers like Chrome or Firefox it’s important for us to keep an eye on the browser market share for all web users. Internet Explorer (IE) still owns a large piece of this pie and because of this, it is important to test sites and applications to ensure they work properly when viewed in IE. This poses a potential problem for developers who do not use Windows.

Although I use OS X on my desktop, I have Windows virtual machines with IE 6,7,8,9 and 10 installed. I also have a Linux virtual machine running Ubuntu so I can check out Chrome/Chromium and Firefox on that platform. In the past I had tried solutions like MultipleIEs but wasn’t satisfied with them. In my experience I’ve found that the best way to see what users are seeing is to have a virtual machine running the same software they are.

I did some IE8 testing for a colleague a short time ago and suggested she should give VirtualBox a shot. Her response was “You should write a blog post about that!”. So here we are.

Free Tools

VirtualBox is a free virtualization application similar to Parallels or VMWare. These …

Piggybak: An Update on End Point's Ruby on Rails Ecommerce Engine

By Steph Skardal
September 24, 2012

With the recent release of one of our client sites running on Piggybak, Piggybak saw quite a few iterations, both for bug fixes and new feature development. Here are a few updates to Piggybak since its announcement earlier this year.

Admin: Continues to Leverage RailsAdmin

Piggybak continues to leverage RailsAdmin. RailsAdmin is a customizable admin interface that automagically hooks into your application models. In the case of the recent project completion, the admin was customized to add new features and customize the appearance, which can be done in RailsAdmin with ease.

As much as I enjoy working with RailsAdmin, I think it would be great in the future to expand the admin support to include other popular Rails admin tools such as ActiveAdmin, which has also gained popularity in the Rails space.

Refund Adjustments

When Piggybak first came out, there was little in the way to allow orders to be monetarily adjusted in the admin after an order was placed. One requirement that came out of client-driven development was the need for recording refund adjustments. A new model for “Adjustments” is now included in Piggybak. An arbitrary adjustment can be entered in the admin, …