This release introduces a few new features and some bug fixes. The new features required some schema changes to the database, so direct upgrading from 1.4 to 1.5 is not possible. Please read the Upgrading document for upgrade information.
There is now a new type of plugin, the Workflow Step Plugin, which should allow rundeck workflows to integrate with more systems in a more direct fashion. These plugins can be either “Workflow Steps” (run once per workflow) or “Node Steps” (run once per node in a workflow.)
Steps can now have Error Handlers which run if the step fails. They will be provided with context data about the reason the step failed.
You will need to update your plugins to work in Rundeck 1.5. Refer to the Developer Guide for more information.