Drivers
Drivers may support any of the following functions:
- Sources – hosts git repositories for projects. Zuul can clone git repos for projects and fetch refs. 
- Triggers – emits events to which Zuul may respond. Triggers are configured in pipelines to cause changes or other refs to be enqueued. 
- Reporters – outputs information when a pipeline is finished processing an item. 
Zuul includes the following drivers: