UNIX and Linux System Administration Handbook, 5th Edition

26	Continuous Integration and Delivery

Until the past decade or so, updating software was a hair-pulling, time-consuming exercise in frustration. Release processes typically involved ad hoc, home-grown scripts that were invoked in enigmatic order and saddled with outdated and incomplete documentation. Testing—if it existed at all—was performed by a quality assurance team that was far removed from the development cycle and often became a major obstacle to shipping code. Administrators, developers, and project managers would plan days-long marathons for the final stages of releasing updates to live users. Service outages were ...