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Jenkins 2.0 Proposal: Introduce a policy for API deprecation

R. Tyler Croy
R. Tyler Croy
October 25, 2015

Over the past few weeks there has been a vibrant discussion happening on the jenkinsci-dev@ mailing list as to what "Jenkins 2.0" means. While Jenkins does not currently adhere to semantic versioning, the change of a major version number does indicate a major milestone for the community.

Project founder, Kohsuke Kawaguchi presented his vision for Jenkins 2.0 in a office hours session, the slides for which can be found in this Google Presentation. Roughly paraphrasing Kohsuke’s vision, 2.0 is primarily about making things better for the thousands of users out there.

This week, we’ll be reviewing some key areas of the "Jenkins 2.0" proposal. Asking you, the user community, to provide feedback on these proposals, going from Jenkins internals to user interface.

Today’s post involves a proposal to introduce a policy for API deprecation from community members Oliver Gondža and Daniel Beck. Extensibility is the heart of Jenkins, but over the past ten years we’ve not had a proper API deprecation policy other than "try not to break plugins, ever."

Daniel, expanding more on the problem wrote:

We have no backward compatibility policy besides "compatibility matters". With 1000+ plugins and basically the entire core being available to plugins, a lot of difficult or impossible to remove cruft has accumulated over the last ten years. This limits both what can be changed in core, and makes documentation difficult to use for plugin developers.

The two have put together a detailed proposal under JENKINS-31035 which suggests we:

limit the availability in APIs (classes, methods, fields, …​) provided by core to a number of releases. Depending on the feature, this can range from a few months, to a few years (e.g. two years being about 100 releases of Jenkins and eight LTS baselines).


I highly encourage you to read the entire proposal on the issue tracker, where we are trying to collect feedback/history.

Providing Feedback

We’re asking you to read the proposal in JENKINS-31035 and provide feedback if you have it.

If you have ever logged in to the issue tracker or the wiki, you have a "Jenkins user account" which means you’ll be able to log into the issue tracker and vote for, or comment on the issue linked above.

(note: if you have forgotten your password, use the account app to reset it.)

We’re going to review feedback, make any necessary adjustments and either approve or reject the proposal two weeks from today.

Stay tuned, and help make Jenkins 2.0 great!

About the author

R. Tyler Croy

R. Tyler Croy

R. Tyler Croy has been part of the Jenkins project for the past seven years. While avoiding contributing any Java code, Tyler is involved in many of the other aspects of the project which keep it running, such as this website, infrastructure, governance, etc.