Building continuous delivery pipelines and similarly complex tasks in Jenkins using freestyle projects and existing plugins is very awkward. You need to mix Parameterized Trigger, Copy Artifact, Promoted Builds, Conditional Build Step, and more just to express what should be a simple script. This project attempts to make it possible to directly write that script, what people often call a workflow (sometimes abbreviated flow), while integrating with Jenkins features like slaves and publishers.

Slides

Not all implemented yet, of course; see below for status.

Your whole workflow is a single Groovy script using an embedded DSL, possibly quite short and legible; there is no need to jump between multiple job configuration screens to see what is going on. Conditions, loops, variables, parallel tasks, and so on are defined using regular language constructs. At any point you can insert a shell script to do “real work” (compilation, etc.).

Standard DSL functions let you run external processes, grab slave nodes, allocate workspaces, build “legacy” (freestyle) jobs, and so on.

If Jenkins is restarted (intentionally, or because of a crash) while your workflow is running, when it comes back up, execution is resumed where it left off. This applies to external processes (shell scripts) so long as the slave can be reattached, and losing the slave connection temporarily is not fatal either.

Flows can pause in the middle and wait for a human to approve something, or enter some information. Executors are not consumed while the flow is waiting.

with.node('linux') { // grab a slave and allocate a workspace
  sh('git clone …');
  sh('mvn verify');
}

Source repository

Not yet using JIRA; waiting for a more or less stable release first. In the meantime we have a Trello board tracking active and proposed tasks.

There is a CI job with validated merge support.

While the implementation is divided into a number of plugins, for ease of prototyping they are all kept in one repository using snapshot dependencies.

• step-api defines a generic build step interface (not specific to flows) that many plugins could in the future depend on.
• basic-steps add some generic step implementations.
• api defines the essential aspects of flows and their executions. In particular, the engine running a flow is extensible and so could in the future support visual orchestration languages.
• support adds general implementations of some internals needed by flows, such as storing state.
• job provides the actual job type and top-level UI for defining and running flows.
• durable-task-step uses the durable-task plugin to define a shell script step that can survive restarts.
• scm-step adds SCM-related steps.
• cps is the flow engine implementation based on the Groovy language, and supporting long-running flows using a continuation passing style transformation of the script.
• stm is a simple engine implementation using a state transition machine, less intended for end users than as a reference for how engines can work.
• aggregator is a placeholder plugin allowing you to mvn hpi:run and see everything working together.