Build triggers (poll SCM, webhook, timer) in Jenkins - Mini Project: Build & Apply

Configure Jenkins Build Triggers: Poll SCM, Webhook, and Cron

📖 Scenario: You are a DevOps engineer setting up a Jenkins job to automate builds. Your goal is to configure different build triggers so the job runs automatically based on source code changes, webhook events, or scheduled times.

🎯 Goal: Learn how to configure Jenkins build triggers using pollSCM, githubPush webhook, and cron triggers in a Jenkins pipeline script.

📋 What You'll Learn

Create a Jenkins pipeline script with a pipeline block

Add a triggers block inside pipeline

Configure pollSCM trigger with schedule H/15 * * * *

Configure githubPush webhook trigger

Configure cron trigger with schedule H 2 * * *

Print a message in the stage to confirm the build runs

💡 Why This Matters

🌍 Real World

Automating builds in Jenkins saves time and reduces errors by running jobs automatically when code changes or on schedules.

💼 Career

DevOps engineers and CI/CD specialists often configure Jenkins build triggers to integrate code changes and automate testing and deployment.

1

Create the basic Jenkins pipeline structure

Create a Jenkins pipeline script with a pipeline block and inside it a stages block containing one stage named Build that runs a steps block with a echo statement printing "Build started".

Jenkins

pipeline {
    // Your code here
}

Need a hint?

Start with pipeline {} and add stages { stage('Build') { steps { echo "Build started" } } }.

2

Add the triggers block with pollSCM

Add a triggers block inside the pipeline block. Inside triggers, add a pollSCM trigger with the schedule set to H/15 * * * * to check for source code changes every 15 minutes.

Jenkins

pipeline {
    // Add triggers block with pollSCM schedule 'H/15 * * * *' here
    stages {
        stage('Build') {
            steps {
                echo "Build started"
            }
        }
    }
}

Need a hint?

Use triggers { pollSCM('H/15 * * * *') } inside the pipeline block.

3

Add githubPush webhook and cron triggers

Inside the existing triggers block, add a githubPush() trigger to enable webhook builds, and add a cron trigger with schedule H 2 * * * to run the build daily at 2 AM.

Jenkins

pipeline {
    triggers {
        pollSCM('H/15 * * * *')
        // Add githubPush and cron triggers here
    }
    stages {
        stage('Build') {
            steps {
                echo "Build started"
            }
        }
    }
}

Need a hint?

Add githubPush() and cron('H 2 * * *') inside the triggers block.

4

Print confirmation message when build runs

Add an echo statement inside the steps block of the Build stage that prints "Build triggered by configured triggers" to confirm the build runs when triggered.

Jenkins

pipeline {
    triggers {
        pollSCM('H/15 * * * *')
        githubPush()
        cron('H 2 * * *')
    }
    stages {
        stage('Build') {
            steps {
                echo "Build started"
                // Add echo to confirm build trigger
            }
        }
    }
}

Need a hint?

Use echo "Build triggered by configured triggers" inside the steps block.