Triggers directive in Jenkins - Mini Project: Build & Apply

Using the Jenkins Triggers Directive

📖 Scenario: You are setting up a Jenkins pipeline for a simple project. You want the pipeline to start automatically when changes are pushed to the main branch in your Git repository.

🎯 Goal: Build a Jenkins pipeline script that uses the triggers directive to start the build automatically on GitHub push events.

📋 What You'll Learn

Create a Jenkins pipeline script with a pipeline block

Add a triggers directive inside the pipeline block

Use the pollSCM trigger with the schedule H/5 * * * *

Print a simple message in the stages section

💡 Why This Matters

🌍 Real World

Automating builds saves time and ensures your software is tested and deployed quickly after code changes.

💼 Career

Knowing how to configure Jenkins triggers is essential for DevOps engineers to automate continuous integration workflows.

1

Create the basic Jenkins pipeline structure

Create a Jenkins pipeline script with a pipeline block and an empty agent any section.

Jenkins

pipeline {
    agent any
    // Your code here
}

Need a hint?

The pipeline block is the main container. Use agent any to run on any available agent.

2

Add the triggers directive with pollSCM

Inside the pipeline block, add a triggers directive that uses pollSCM with the schedule H/5 * * * *.

Jenkins

pipeline {
    agent any
    triggers {
        // Your code here
    }
}

Need a hint?

The pollSCM trigger checks the source code every 5 minutes for changes.

3

Add a simple stage to print a message

Add a stages section with one stage named Build that runs a steps block containing echo 'Build started'.

Jenkins

pipeline {
    agent any
    triggers {
        pollSCM('H/5 * * * *')
    }
    stages {
        // Your code here
    }
}

Need a hint?

The stages section organizes your pipeline steps. Use echo to print messages.

4

Print the pipeline script to verify

Print the entire Jenkins pipeline script by running it in Jenkins or displaying the script content.

Jenkins

// Your code here to print or display the pipeline script

Need a hint?

In Jenkins, the pipeline script is saved and run automatically. The output will show the echo message when triggered.