Jenkins in the CI/CD ecosystem - Step-by-Step Execution

Process Flow - Jenkins in the CI/CD ecosystem

Code Commit

↓

Jenkins Detects Change

↓

Build Stage

↓

Test Stage

↓

Deploy Stage

↓

Feedback & Monitoring

↓

Developer Fixes Issues

↓

Code Commit

This flow shows how Jenkins automates the steps from code commit to deployment and feedback in CI/CD.

Execution Sample

Jenkins

pipeline {
  agent any
  stages {
    stage('Build') { steps { echo 'Building...' } }
    stage('Test') { steps { echo 'Testing...' } }
    stage('Deploy') { steps { echo 'Deploying...' } }
  }
}

A simple Jenkins pipeline that runs build, test, and deploy stages sequentially.

Process Table

Step	Action	Stage	Output	Next Step
1	Detect code commit	N/A	Change detected in repository	Start Build stage
2	Execute build	Build	Building...	Start Test stage
3	Execute tests	Test	Testing...	Start Deploy stage
4	Execute deploy	Deploy	Deploying...	Pipeline complete
5	Pipeline ends	N/A	All stages completed successfully	Wait for next commit

💡 Pipeline ends after Deploy stage completes successfully

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
Pipeline Stage	None	Build	Test	Deploy	Complete	Complete
Build Status	Not started	Running	Success	Success	Success	Success
Test Status	Not started	Not started	Running	Success	Success	Success
Deploy Status	Not started	Not started	Not started	Running	Success	Success

Key Moments - 2 Insights

Why does Jenkins start the Test stage only after the Build stage finishes?

Because the execution_table shows that the Test stage begins only after the Build stage outputs 'Building...' and completes successfully at Step 2.

What happens if the Deploy stage fails?

The pipeline would stop at the Deploy stage, and the final row in execution_table would show failure instead of 'All stages completed successfully'. This example assumes success for clarity.

Visual Quiz - 3 Questions

Look at the execution_table, what is the pipeline stage after Step 2?

A Build

B Test

C Deploy

D Complete

💡 Hint

Check the 'Stage' column in row with Step 3 to see which stage runs after Step 2.

According to variable_tracker, what is the status of the Test stage after Step 3?

A Not started

B Running

C Success

D Failed

💡 Hint

Look at the 'Test Status' row under 'After Step 3' column.

If a new code commit happens after Step 5, what is the next action Jenkins will take?

A Start Build stage again

B Start Deploy stage

C Wait without action

D Restart Test stage

💡 Hint

Refer to the 'Next Step' column in the last row of execution_table.

Concept Snapshot

Jenkins automates CI/CD by detecting code commits,
then running Build, Test, and Deploy stages in order.
Each stage must complete before the next starts.
Successful completion triggers feedback and waits for new commits.
This pipeline ensures fast, reliable software delivery.

Full Transcript

Jenkins is a tool that helps automate software delivery. When a developer saves code, Jenkins notices the change. It then runs a series of steps: building the code, testing it, and finally deploying it. Each step happens one after the other. If all steps succeed, Jenkins finishes and waits for new code changes. This process helps teams deliver software quickly and safely.