December 22, 2009 4 Comments
By Chris L Hardin
Sr. Software Architect
Hudson is without a doubt the best tool I have used this year in my projects. Continous integration is very important in an Agile development environment, but it most often involves developers committing time and effort into making it happen and it’s a consistent effort that never seems to end. Hudson and Cruise Control are two solutions that change all that.
Let me preface this by saying that I started out using Cruise Control for a month and I then I tried Hudson and in just a few hours, I had removed Cruise Control and I never looked back. Cruise Control has it’s merits but Hudson has all the same functionality plus much much more. I highly recommend the migration if you are still stuck with Cruise Control.
Hudson is a Java project that you can deploy standalone or in a web container like Tomcat. It supports building multiple types of projects and tasks and it has a few hundred plugins to customize its functionality. Hudson is a great tool out of the box, but once you browse and install a few plugins, it really comes into it’s own.
I spent 5 minutes installing Hudson into Tomcat and then I created a new project through the interface. In the configuration, you can tell Hudson where your project is, SVN, CVS, etc. You set how you build your project, whether it is Maven or Ant and then you are off. Hudson has no limits to the configuration options. You can configure it to poll your version control periodically to look for changes, or build every so often or you can build on demand only. You can configure the project to automatically deploy to a container, publish to a repository and archive your builds.
In a project where I used Hudson, I set a series of projects to build periodically by polling SVN and if there was a change, it would trigger a chain of projects to build to create the final project and deploy the enterprise to a container.
Hudson requires a dedicated server. You don’t really want to run this on your desktop. My recommendation is take a decent Linux machine and dedicate it to running your builds and give it plenty of disk space to archive your builds.
Hudson also integrates with tools such as Polarion, ViewCVS and WebSVN to give you reports and link back from changes to see the source. It also will aggregate reports from several sources including Junit reports, TestNG reports, Checkstyle reports, Crap4j and more. Again this is where the plugins are key.
Hudson is easy to maintain and upgrade. Just make sure your HUDSON_HOME environment variable is set to a location where you want all the work to happen and make sure that location is redundant. Don’t store anything under the hudson directory that gets created when the container starts. To upgrade, just simple replace the hudson directory and war file and start your container and that’s it.
Installing a plugin is as simple as going to the plugin page of the Hudson management screen and choosing the plugins you want and download. It will also let you know when there is a new version of an installed plugin.
Hudson will also cluster together multiple machines and allow you to control them from a single instance. You just add machines as slaves by running the slave.jar on the machines you want to cluster and tell the master Hudson instance where these are. When builds run, Hudson will utilize resources on the other machines to accomplish builds as well as the master machine. This functionality isn’t as useful if you have projects that depend on each other. I recommend avoiding having projects depending on others if you can but this is often impossible since all projects should inherit from a set of common framework projects in an enterprise to avoid code duplication and promote reuse.
Hudson has a robust email and notification mechanism with keeping up with build statuses. You can configure emails to be sent to a group on success, emails to be sent to developers who are the culprit behind a failing build and you can even configure options such as Twitter and Calendar updates at the end of a build. There is no shortfall of notifications and events in the system.
The server also had a very pleasing interface. It’s very professional looking and has quite a few Ajax-enabled components.
This tool definitely has it all and the best part is that a trained monkey could configure it. Also, once you get your projects running in it, which doesn’t take long, you can be hands off and coding while Hudson is taking care of your developer and QA builds. You can eve setup deployments to automate your production deployments and set permissions for users to set who can and cannot do certain tasks.
There really isn’t a point if asking if Hudson supports a certain configuration because there is always a plugin to accomplish the task at hand if the out of the box configuration won’t do it. Hudson will save you time, many and make a better software product in the process. You can’t lose. What are you waiting for? Download Hudson today.