OpenStack projects have gated trunks -- that is, every change to an OpenStack project must pass unit and integration tests. Each one requires a number of Jenkins jobs to accomplish this, and some support within the project in the form of configuration files and test interfaces. Until recently, this was managed in an ad-hoc manner, but as we add projects and tests, it won't scale. We currently have 235 Jenkins jobs, and that's way too many to manage manually.
Enter the standardized Project Testing Interface. It lays out all the processes for testing and distribution that a project needs to support to work with the OpenStack Jenkins system. By standardizing this, we can start to manage Jenkins jobs collectively instead of individually. This means that not only is it easier to add new projects, but we can be sure that existing projects benefit from improvements in the system and avoid bit-rot.
The OpenStack Common project helps ensure that the code in each project that handles project setup, dependencies, versions, etc, is kept in sync and standardized. The Project Testing Interface depends on openstack-common for the project-side of its implementation.
Finally, the OpenStack CI team (Andrew Hutchings in particular) has been developing a system to manage our Jenkins configuration within puppet. That's how we plan on managing groups of Jenkins jobs, and it also means that changes to the Jenkins configuration can go through code review, just like any other change to the project. Anyone can submit changes to the running Jenkins configuration without any special administrative privileges.
All of these efforts came together this morning when we bootstrapped the Cinder project, the breakout of the volumes component from Nova. Adding "cinder" to the list of standard python jobs in puppet caused all of our standard packaging and gating jobs to be created in Jenkins. OpenStack Common generated the skeleton code for the project that conforms to the Project Testing Interface. And when that code was submitted for review, it passed the automatically-created gate jobs. From an infrastructure standpoint, Cinder went from an empty repository to a fully integrated OpenStack project in just a few minutes.