Demo Jenkins Git hub Integration and Maven Build

In this guide, you’ll learn how to integrate GitHub with Jenkins using webhooks to trigger automated builds. We’ll also demonstrate how to configure a simple Maven build within a Jenkins pipeline. By the end, you’ll have a fully automated CI workflow for your Java projects.

1. Set Up GitHub Webhook

1. Open your GitHub repository in the browser.
2. Navigate to Settings > Webhooks.
3. Click Add webhook.

4. Configure the webhook fields as follows:

5. Click Add webhook.

2. Create a New Jenkins Pipeline Job

1. Go to your Jenkins dashboard.
2. Click New Item.
3. Enter a name (e.g., devsecops-numeric-application).
4. Select Pipeline, then click OK.

3. Configure the Pipeline

In the job’s Configure screen:

1. Under Build Triggers, enable GitHub hook trigger for GIT SCM polling.

2. Scroll to Pipeline:

   • Definition: Pipeline script from SCM
   • SCM: Git
   • Repository URL: https://github.com/your-org/your-repo.git
   • Branch: main

3. Click Save.

4. Define Your Jenkinsfile

At the root of your GitHub repository, add a file named Jenkinsfile:

pipeline {
    agent any

    stages {
        stage('Build Artifact') {
            steps {
                // Compile and package without running tests
                sh "mvn clean package -DskipTests=true"
                // Archive the JAR for download
                archive 'target/*.jar'
            }
        }
    }
}

This pipeline uses the any agent, runs the Maven package goal, skips tests, and archives the resulting JAR.

5. Run Your First Build

1. Commit and push the Jenkinsfile:

   git add Jenkinsfile
   git commit -m "Add Jenkins pipeline for Maven build"
   git push origin main
   

2. In Jenkins, open your pipeline job and click Build Now.

3. Monitor the console output. The initial build will download all dependencies.

6. Automate Builds via Webhook

Now every push to main triggers a new build automatically. For example:

git commit -am "Remove outdated comment"
git push origin main

Jenkins will start a fresh build as soon as GitHub sends the webhook event.

7. Verify Webhook Deliveries

To inspect delivery logs:

1. In your GitHub repo, go to Settings > Webhooks.
2. Click on the webhook entry.
3. Review Recent Deliveries for payloads and response codes.

8. Sample Webhook Payload

Below is a trimmed example of the JSON GitHub sends on a push:

{
  "ref": "refs/heads/main",
  "before": "45be219a25dfe24f251196152de6df004b7c02e",
  "after": "2d66f5307c8f2d0d9ea1e6b1982ef187f8b33a21",
  "repository": {
    "id": 376897057,
    "name": "devsecops-k8s-demo",
    "full_name": "sidd-harth/devsecops-k8s-demo",
    "private": false,
    "owner": {
      "login": "sidd-harth",
      "id": 2892541,
      "avatar_url": "https://avatars.githubusercontent.com/u/2892541?v=4"
    }
  }
}

Links and References

• Jenkins Documentation
• GitHub Webhooks
• Maven Getting Started Guide