OpenVeda Playbook: Jenkins

Your definitive guide to contributing to the world's leading open-source automation server.

1. The "Why": Mission & Impact

• The Mission: Jenkins is an open-source automation server which helps automate the parts of software development related to building, testing, and deploying, facilitating continuous integration and continuous delivery (CI/CD).
• Why it's great for your career: If you want a career in DevOps, SRE, or Backend Engineering, contributing to Jenkins is a massive signal. It proves you understand the CI/CD pipeline, a core concept in modern software. They have a structured GSoC program and are highly respected in the enterprise world.

2. The "What": Tech Stack

• Core Stack: Java. The Jenkins core and the vast majority of its thousands of plugins are written in Java (typically Java 11 or 17).
• Frontend: JavaScript (primarily using the Jelly templating engine for UI, with modern plugins adopting React).
• Build Tool: Apache Maven.
• Key Tools: Jira for issue tracking, GitHub for source code.

3. The "How": Your Onboarding Journey

3.1: Join the Community

• Primary Channel (Mailing List): The core of the community. Introduce yourself here.
  • Link: Jenkins Developer Mailing List
• Secondary Channel (Gitter/IRC): For real-time chat, especially for newcomers.
  • Link: Gitter Channel for New Contributors

3.2: The Setup Guide

• Official Guide: Jenkins has a fantastic, detailed guide for setting up your development environment.
  • Link: Jenkins Developer Guide - Setup Environment
• OpenVeda Pro-Tip: Follow their guide for setting up with mvn clean install first. Then, the easiest way to run a test instance of Jenkins with your plugin is with mvn hpi:run. This will save you a lot of time.

3.3: The Contribution Workflow

• Official Guide: Their workflow is well-documented and standard for a mature project.
  • Link: Beginner's Guide to Contributing
• Key Point: Most contributions are made to individual plugins, not the Jenkins core. Your first step is to find a plugin that interests you.

4. GSoC History & Focus Areas

• Historical Focus: Jenkins is a GSoC legend. Projects usually focus on creating new plugins, modernizing the UI of existing plugins, improving cloud integrations (like with Kubernetes or Docker), and enhancing security features.
• What Mentors Look For: A clear understanding of Java and Maven. They value developers who can write clean, maintainable code. Making a small contribution to a plugin before GSoC is the best way to get noticed.

5. Key Repositories to Know

• Jenkins Core: github.com/jenkinsci/jenkins (You will likely not touch this at first).
• Plugin Repositories: Most plugins are under the jenkinsci organization on GitHub. Example: Git Plugin.

6. Find Your First Task Right Now

• The Golden Link: Jenkins uses the "newbie-friendly" label on their Jira issue tracker. This is the best place to start.
  • Link: "newbie-friendly" issues on Jira
• Hacktoberfest: They also often use a hacktoberfest label on GitHub issues within various plugin repositories.

7. The Unwritten Rules (Mentor Insights)

• Plugin-First Mentality: Your journey starts with a plugin. Find a small, popular plugin and see if you can fix a small bug or improve its documentation.
• Follow the Java Conventions: Jenkins has a very established Java codebase. Follow their coding style and conventions strictly.
• Understand Maven: You don't need to be a Maven expert, but you should understand the basics of pom.xml and the build lifecycle.