Jenkins

Definition

Jenkins is a widely used open-source automation server that lets teams build, test, and deploy software automatically through configurable CI/CD pipelines.

Overview

Jenkins began life as Hudson, a continuous integration server created by Kohsuke Kawaguchi while working at Sun Microsystems, and was renamed Jenkins after a licensing dispute following Oracle's acquisition of Sun. It went on to become one of the most widely deployed automation servers in the industry, largely due to its enormous plugin ecosystem covering everything from source control integrations to cloud deployment targets. At its core, Jenkins watches for triggers, such as a new commit pushed to GitHub or GitLab, and then runs a defined pipeline of steps: compiling code, running tests, building Docker images, and deploying to environments like Kubernetes. Pipelines are typically written as code in a Jenkinsfile using a Groovy-based DSL, which lets build logic live in version control alongside the application it builds. Jenkins predates many newer CI/CD platforms and remains especially common in enterprises with complex, highly customized build requirements, where its plugin ecosystem and self-hosted flexibility outweigh the setup effort compared to hosted alternatives like GitHub Actions. Teams learning modern pipeline concepts often compare Jenkins directly against newer tools, a comparison covered in depth in the CI/CD explained guide.

Key Features

• Massive plugin ecosystem covering source control, cloud, and testing tools
• Pipeline-as-code via Jenkinsfile using a Groovy-based DSL
• Self-hosted, giving full control over build infrastructure
• Distributed builds across multiple agent machines
• Extensive support for triggers, webhooks, and scheduled builds
• Blue Ocean and classic UIs for visualizing pipeline execution
• Long-standing community with extensive documentation and plugins

Use Cases

Frequently Asked Questions

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