Kochiku-worker is the builder component of Kochiku. The worker code is deployed to each computer that runs BuildAttemptJobs, which are enqueued by BuildPartitioningJobs from Kochiku.
Since Kochiku uses Resque jobs, a kochiku-worker is essentially just a Resque worker. All of the techniques that you can use with Resque workers, such as the environment variables and Unix signals, also work with Kochiku workers.
See the Running Kochiku in development section of the Hacking on Kochiku wiki page.
See the Installation & Deployment page of the Kochiku wiki.