DevOps World | Jenkins World 2019 San Francisco

"Shared libraries enable Jenkins administrators and developers to make standard functionality available for use in pipeline jobs. When done properly, the libraries simplify Jenkins files, ensure compliance steps are performed, and allow easy customization of jobs. When done wrong they become a never-ending nightmare of complicated code updates, breaking changes, untold numbers of support tickets, and unhappy users. At Liberty Mutual we charged headlong into pipelines with no hesitation...or planning. After two years of development we were left with over 20000 lines of incomprehensible code—it was difficult to update and impossible to unit test. We’ve refactored many methods, but with so much untestable code, this effort was fraught with danger. The decision was made to scrap the entire codebase and start from scratch.

In this session we will dive into the mistakes that were made and how to avoid them. We will cover the basics of planning the code structure, modular methods, and how to test. We will also discuss the inner source model Liberty uses to extend pipeline functionality by allowing users to contribute code."