I’m working on a rather large reporting and analytics application that runs on top of Hadoop at work. It has tests. A whole bunch of them, actually. That’s good.

So far, we’ve been running the tests manually when making new releases. But doing it more often is always better, since it gives you an indication on when things went wrong, and also forces you to keep your tests in a state where they pass. Some people call it Continous Integration.

Now, you can do all the work getting your builds to build and run tests yourself, via cron and scripts and other types of messiness. Or you can try an existing solution. Today I decided to try Hudson.

That turned out to be embarrasingly simple to get started with. Basically, it’s a matter of:

1. Downloading hudson.war from their site.
2. Start it by running java -jar hudson.war
3. Go to http://localhost:8080 with a web browser of your choice. That would be Opera in my case. You have to eat your own dog-food.
4. Go to the Hudson management screen and enable the git plugin
5. Setup a new project. Tell it where the code is and on which branch.
6. Configure what commands to run to build and test. Make the test command output an xunit xml file.
7. Tell Hudson where that xml file is.

Result: Hudson will periodically poll git and run my build and test commands, then show a changelog and what tests failed. All this after 30 minutes of setup time. I’m impressed.