Open watcher: Nilfs file system and concourse CI

NILFS is a log-structured file system supporting versioning of the entire file system and continuous snapshotting, which allows users to even restore files mistakenly overwritten or destroyed just a few seconds ago.

NILFS was developed by NTT Laboratories and published as an open-source software under GPL license, and now available as a part of Linux kernel.

Built on the simple mechanics of resources, tasks, and jobs, Concourse presents a general approach to automation that makes it great for CI/CD.