Tracking configuration changes in Jenkins

Continuous Integration is a pretty common concept these days. The idea of a “robot buddy” which builds and runs a bunch of tests across a whole codebase every time a change is checked in to the source code repository seems a generally good idea. There are a range of possibilities how to achieve this, and one of the most popular is Jenkins, the open source version of Hudson, originally a community project but now owned by Oracle.

Although Jenkins is a useful tool, it can be a bit fiddly to set up, with a lot of web-form-filling to configure it for your projects once the basic web app is installed. Most projects I have worked on which use Jenkins have started by working through this setup using trial and error, then stuck with something which seemed to work. In an optimistic world this is OK, but it fails whenever there is a problem with the machine running the CI service, if another one is required, or if someone makes a change which breaks the configuration and the team needs to quickly roll back to a working config. In short it’s like software development used to be before we all used version control and unit tests!

With all this in mind, I was interested to read an article about a Jenkins plugin for version-controlling the configuration. This could be a step in the right direction.

Tracking configuration changes in Jenkins – cburgmer's posterous.

If you use Jenkins this seems a very good thing to try out. I still feel, though, that all this configuration does not really belong in a CI tool. It’s really just some instructions about how how to build, deploy, and test the product, and to my mind that’s the kind of stuff which belongs with the code itself.

Imagine how simple things would be if there was no need for a whole CI “server”, but we could just use a simple git hook which called something managed, edited, tested and checked in with the code itself.