🔁 First Jenkinsfile

First Jenkinsfile: A Jenkins Pipeline is a factory assembly line: each 'stage' is a workstation (Build, Test, Deploy), items move through in order, and if one station fails, the

A Jenkins Pipeline is a factory assembly line: each 'stage' is a workstation (Build, Test, Deploy), items move through in order, and if one station fails, the whole line stops and the team is alerted. You write this assembly line as code, in a file called Jenkinsfile. So why write the pipeline as code instead of clicking through a UI to configure jobs (the old 'Freestyle Job' approach)? Because a UI-configured job lives only on the Jenkins server — nobody reviews it, nobody versions it, and it silently diverges from what the team thinks is running. A Jenkinsfile, by contrast, sits in the same repo as the source code and goes through the same pull-request review as any Java class change. That difference is exactly why a 'pipeline as code' incident is rare but a 'someone clicked a checkbox in the Jenkins UI six months ago and nobody remembers why' incident is common.

Freestyle Job vs Declarative Pipeline

Your First Jenkinsfile

Minimal Declarative Pipeline

Micro Lab: Jenkinsfile pipeline stage completion

Replace the TODO line with the critical line from the expected solution. This is not a real runtime; the goal is to reinforce writing the correct structure in a controlled way.

Step by Step: Jenkinsfile pipeline stage completion

Choose execution place with pipeline and agent

Fetch source code with checkout

Run the build/dependency stage

Produce evidence in the test stage

Publish reports and notifications inside post always

Order the Jenkinsfile quality-gate flow.

CI/CD Pipeline — Live Simulation