API Strategy & Practice Conference 2017

OpenStack ran into a challenge: how do you balance the ability to evolve a REST API, with backwards compatibility guarantees, and have it work the same across different deployments, when you have no control over when they are going to upgrade. The answer we came up with was labeled "Microversions", inspired by HTTP content negotiation. This talk will dig into the challenges of versioning REST APIs, as well as the unique challenges of versioning ones that expect to exist in interoperable public clouds. It will dive through ideas that were tried and retired in OpenStack, and describe in depth the microversion system that many OpenStack services now use. We'll look at what's been learned in 2 years of this in the field, and suggest how related approaches might be applied to other open source projects.