How can a Jenkins Ivy Project be converted to a Freestyle Project?

Question

After a recent update (both Jenkins and Plug-ins) my Ivy Project settings can no longer be changed due to incompatible layouts (table to div change in a minor version update, from Jenkins 2.263 to 2.264). This broke every plugin that was involved in configuring projects, but went unnoticed for two months because our project settings haven't needed to change in quite a while, and the builds were still working fine in the meantime.

For reference, my build process is based on:

• Ant for the build
• Ivy for dependency resolution
• Artifactory as a dependency repository
• Subversion as a code repository (with Jenkins commit triggers)
• Junit with Cobertura, Jmeter
• FindBugs, CheckStyle, CLOC
• Projects are based on Java and JavaDoc

I tried reverting to the earlier version of Jenkins, but this affected nearly every plugin, and I wasn't able to successfully revert to the plugin version combination from prior to the breaking update. After failing to revert the updates, I decided instead to plow forward in updating all of our 68 projects to accommodate the new plugin versions.

Unfortunately, I can't save any configuration changes to Ivy Projects. After trial and error, I've found that I can re-produce my builds using Freestyle Projects. However, Jenkins doesn't seem to offer any way to convert projects from one type to another. If I were to create new projects from scratch to replace my existing projects (all 68, including their dependencies and specific plugin settings), I would lose all of my previous build histories, including the build numbers (which carry over to our deployments) and our project metrics (which we use for performance evaluation). So, I don't want to lose all of that information.

How can I manually change an Ivy Project to a Freestyle Project?

Answer 1

I found a partial solution, but it doesn't seem to work for all projects.

• Stop the Jenkins webapp (important).
• For each Ivy Project that you want to convert to a Freestyle Project, rename the root element of jobs/[project]/config.xml from <hudson.ivy.IvyModuleSet plugin="ivy@2.1"> to <project> (don't forget to also change the closing tag at the end of the document from </hudson.ivy.IvyModuleSet> to </project>.
• Restart Jenkins.

For most projects, I am then able to change the project configuration and save (importantly, Ant/Ivy-Artifactory Integration in a Freestyle Project is a feature-matched substitute for an Ivy Project).

However, three other projects still show up as Ivy Projects after changing the root element tag. What these projects had in common was that they all use the Performance Plugin. In order to finish converting these to Freestyle, I needed to additionally:

• Disable the Performance Plugin
• Restart Jenkins
• Edit/Save the configuration for those projects as above.

Side effects and special considerations:

• All of my build timestamps (prior to the change) are now listed as Dec 31, 1969 7:00 PM EDT, with a most recent build time as 50 yr. New build timestamps are correct. This likely was the result of no longer depending on the CloudBees plugin for build pipelines, which mapped build timestamps to build versions to avoid an old regression bug.
• Every project immediately changed to red (Failed) on the dashboard, even though no builds had been attempted after the update, and the previous status was blue (Success) or yellow (Unstable). I suspect this is related to the above issue. After the next attempted build, whether successful or not, the status accurately reflects the build status.
• No ability to use the Performance Plugin.
• Several projects now show up as both an Upstream and Downstream Project, causing endless build cycles. There were three cases of this involving different combinations of projects, and in those cases, one or both projects needed to be removed from the build triggers. I suspect it had been this way for a while but for some reason the endless cycles only happen after the update.
• I suddenly have a lot of "Unreadable Data" across all of my Jenkins projects. Unfortunately, discarding it is an all-or-nothing process (can't pick a single project to test). I backed up my jobs directory and clicked Discard, and to my surprise everything still works.

It looks like I'm back in business. My build numbers have been preserved, and the only noticeable side effect is the 50 year old builds. If I encounter any other issues resulting from these changes, I will update this answer.