One joke floating around the Net is a list of lies that companies tell potential hires to seem more with it. Running a continuous integration server is near the top.
Everyone likes the idea of constantly checking the code to make sure it works, but no one wants to do all of the work required to both maintain the code and keep the continuous integration server up and running.
CloudBees would like to change this. Not only does the company offer a cloud for deploying your applications, but it provides a cloud to build them too. Your account is more than just a way to serve your data to the masses. There's a code repository (Git or Subversion) and a Jenkins server watching every piece of code you check in.
After a bit of fiddling, I was able to check in code and wait for Jenkins to build it, test it, compile the documentation and deploy it to the server. If I needed more, there were plenty of other services, plugins and switches to flip.
The theory is that CloudBees has plenty of high end boxes working in parallel to build your huge pile of code. Instead of waiting for your desktop machine to page in the right libraries, you can let Jenkins parcel out your build to the racks at CloudBees.
I didn't see this advantage, but my web application had just one class and one JSP. The web interface to Jenkins comes with a neat progress bar and a flashing blue ball that made it clear that my local machine could build these few files faster than the leviathan in CloudBees' data centre.
Even if small projects won't tap the power of the cloud, they'll still be able to use the discipline of Jenkins. It took me a few minutes of poking and prodding to get the code to flow all the way through the build pipeline, but after that I was golden. It's nice to let someone else worry about keeping Jenkins running.
The CloudBees cloud is essentially Tomcat and MySQL, but other databases are available, including some from third parties with tight integration. Cloudant, for instance, offers CouchDB services and MongoHQ serves up MongoDB.
CloudBees offers servers as "app cells," a unit of power that's roughly one eighth of a standard Amazon EC2 server. The memory and compute cycles are tied together, so you essentially buy the servers by the eighth.
CloudBees offers a generous set of free services, but the constraints are tight. Only the casual developers will be happy within them. Anyone engaged in serious work will quickly need to upgrade to a paying service.