WorldTurner Blog

Stateless computing as I see it

Stateless computing has had some press coverage in the past. What it means to me is that you don't deliver your software as some package that you need to install on a computer, but rather as the entire configuration of the computer as a whole. Let me describe what the advantages are and what you need to do to achieve it.

Posted at 07:59PM Mar 06, 2011 by Erwin Bolwidt in DevOps  |  Comments[2]

Ruby disk utilities - partition editor

In my previous blog post, I described how I was able to create a bootable disk image with a Ubuntu installation, without any manual intervention. Although that was a good first step, I don't consider this an end-result as the shell scripts that I used weren't very error-tolerant or configurable. My next goal is to create a ruby script that can perform these steps, and also pick up where it left of if an error was encountered. As part of this, I am creating a library of utilities related to disk management.

Posted at 10:03AM Feb 20, 2011 by Erwin Bolwidt in DevOps  |  Comments[0]

Creating a bootable virtual appliance, fully automated

I was looking for a way to create a VMWare image in an automated way, without actually having to start VMWare to make the image.

I can much easier integrate such a process into an automated build than if I actually have to start VMWare, and I'm not even sure if I can entirely automate an OS installation inside VMWare.

The goal is to include the building of deployable machine images into the continuous integration process, and to be able to recreate exactly the same machine configuration without having to worry what changes may have been made by hand.

Many steps turned out te be relatively straightforward since people already figured this out or even created tools for the step. However, making the image bootable using Grub 2 was a major challenge for me, and I couldn't find any resource on the Internet that described how to do this.

Posted at 11:45AM Feb 04, 2011 by Erwin Bolwidt in DevOps  |  Comments[0]

New release of Google Maps Shadowmaker

I release the first version of Shadowmaker quite some time ago. It is an image manipulation program that will automatically create a "shadow" image for an icon, according to the rules specified by Google maps. It gives a 3D-like appearance to markers that you place on a map.
It is useful for anyone who creates applications or mashups with Google maps and doesn't want to go through several steps in your favorite image editing program (such as Photoshop, Gimp or the like)

This new release does not add new functionality, but it does add support for Google Maps version 3. The application itself is now built using version 3, and the code snippets generated by the application also generate version 3 code.

Please check it out at http://www.cycloloco.com/shadowmaker/

Posted at 07:56AM Aug 27, 2010 by Erwin Bolwidt in General  |  Comments[0]

Google Analytics, Wicket and Panels

In this post I will go into ways to provide useful information to Google Analytics from your wicket components. For example, even if you stay on the same WebPage in wicket, you can still track the components on that page using Google Analytics.[Read More]

Posted at 03:16PM Aug 20, 2010 by Erwin Bolwidt in Wicket  |  Comments[1]

Refactoring wicket Pages to Components

Refactoring wicket Pages to Components We had an existing codebase that we wanted to refactor. It is an administrative GUI for a larger application with many different areas that need to be administered. The functionality was developed as wicket Pages, not Components. We wanted to integrate them in a tabbed user interface, and for that we wanted to use the TabbedPanel component from the wicket-extensions library. In this article I'll explain the steps we took to refactor this page-based application into a component-based application.[Read More]

Posted at 03:03PM Aug 20, 2010 by Erwin Bolwidt in Wicket  |  Comments[0]

Wicket best practices: Components vs Pages

Wicket has two kinds of building blocks for your applications: Components and Pages. Pages are top-level components, they exist by themselves and cannot be used as part of other Pages or Components. Components can be put on Pages or placed inside other Components. When you're developing using Wicket, you have to choose to make your own classes extend Page or Component. This post offers some insights in the pros and cons of each choice.[Read More]

Posted at 01:33PM Aug 20, 2010 by Erwin Bolwidt in Wicket  |  Comments[2]

Technical Hickups

This blog has had some technical problems. Due to some extremely good weather in the Netherlands, combined with the Tour de France (I'm a big cycling fan, especially when I am riding myself) and the World Championship of Football (hard to miss, and great atmosphere, even though I'm normally not much of a football fan myself) I haven't gotten around to fully repairing it yet.

Did you know that Holland stands a good chance of ending up in the finals, and a decent chance of winning the championship?

Compounding the problem is the fact that my backups aren't in a format that I could directly use again. I still have the articles, but not the blog layout and the attachments, so I need some more time to recover this. Yes, backups are good, checking that you can actually restore them is better. No bad thing is without a good lesson.

Posted at 06:34PM Jul 06, 2010 by Erwin Bolwidt in General  |  Comments[0]