Demo Refactor existing Jenkinsfile

In this lesson, we’ll walk through refactoring our existing Jenkinsfile to serve as the foundation for more advanced pipeline demos. You’ll learn how to:

Extract reusable helpers (e.g., Slack notifications)
Simplify and structure stages for clarity
Spin up a new feature branch for future enhancements
Verify the pipeline in both classic and Blue Ocean views

By the end, you’ll have a lean, maintainable Jenkins pipeline ready for advanced integrations.

Recap: Jenkins Multibranch Pipeline

Log in to your Jenkins instance and find the multibranch Organization Folder containing the solar-system repository. This setup automatically discovers and builds branches as they appear in your Git server.

The image shows a Jenkins dashboard displaying a list of build jobs with their statuses, last success and failure times, and durations. The interface includes options for managing Jenkins and viewing build details.

Within solar-system, our last active branch was feature/enabling-slack.

The image shows a Jenkins dashboard for a project named "solar-system," displaying the status of different branches with details on their last success, last failure, and duration.

On the Git side, the project lives under the dasher-org organization in Gitea alongside related repositories.

The image shows a Gitea organization page named "dasher-org" with a list of repositories, including "solar-system" and others, along with options to create a new repository or migration.

We pushed our last updates to the feature/enabling-slack branch.

The image shows a Git repository interface with a list of files and their commit messages, including a recent push to the branch "feature/enabling-slack."

Step 1: Open the Jenkinsfile in VS Code

Switch your local repo to feature/enabling-slack and open Jenkinsfile in Visual Studio Code (or your preferred editor).

The image shows a Visual Studio Code interface with a file explorer on the left, displaying a project directory named "solar-system" and a "Jenkinsfile" open in the editor. The terminal at the bottom indicates an SSH connection to a server.

Ensure you have the following installed on your Jenkins agents:

Node.js & npm
Docker Engine
Trivy scanner
Slack Notification Plugin

Step 2: Extract Slack Notification Helper

To avoid repeating slackSend calls and status logic, define a reusable helper function at the top of your Jenkinsfile:

// Slack Notification helper
def slackNotificationMethod(String buildStatus = 'STARTED') {
    buildStatus = buildStatus ?: 'SUCCESS'
    def color = (buildStatus == 'SUCCESS') ? '#47ec05' :
                (buildStatus == 'UNSTABLE') ? '#d5eed0' : '#ec2805'
    def msg = "${buildStatus}: ${env.JOB_NAME} #${env.BUILD_NUMBER}:\n${env.BUILD_URL}"
    slackSend(color: color, message: msg)
}

This helper centralizes notification logic and can be invoked in any post block.

Step 3: Simplify Pipeline Structure

We’re focusing on five key stages for our advanced demos. Comment out or remove any extra stages. The new skeleton looks like this:

pipeline {
    agent any

    options {
        timestamps()
        skipDefaultCheckout()
    }

    environment {
        MONGO_URI          = "mongodb+srv://supercluster.d83jj.mongodb.net/superData"
        MONGO_DB_CRED      = credentials('mongo-db-credentials')
        SONAR_SCANNER_HOME = tool 'sonarqube-scanner-610'
        GITEA_TOKEN        = credentials('gitea-api-token')
    }

    stages {
        stage('Installing Dependencies') { steps { sh 'npm install --no-audit' } }
        stage('Dependency Scanning') {
            parallel {
                stage('NPM Dependency Audit') { steps { sh 'npm audit --json > audit.json' } }
                // OWASP Dependency Check removed for this demo
            }
        }
        stage('Unit Testing')    { steps { sh 'npm test' } }
        stage('Code Coverage')   {
            steps {
                catchError(buildResult: 'SUCCESS', message: 'Coverage issues', stageResult: 'FAILURE') {
                    sh 'npm run coverage'
                }
            }
        }
        stage('Build Docker Image') { steps { sh 'docker build -t ${env.JOB_NAME}:${env.GIT_COMMIT} .' } }
        stage('Trivy Vulnerability Scanner') {
            steps {
                sh '''
                  trivy image ${env.JOB_NAME}:${env.GIT_COMMIT} \
                    --severity LOW,MEDIUM,HIGH --exit-code 0 --format json \
                    -o trivy-image-MEDIUM-results.json
                  trivy convert --format template \
                    --template "/usr/local/share/trivy/templates/html.tpl" \
                    --output trivy-image-MEDIUM-results.html \
                    trivy-image-MEDIUM-results.json
                  trivy convert --format template \
                    --template "/usr/local/share/trivy/templates/junit.tpl" \
                    --output trivy-image-CRITICAL-results.xml \
                    trivy-image-MEDIUM-results.json
                '''
            }
            post {
                always {
                    publishHTML(
                      allowMissing: true,
                      alwaysLinkToLastBuild: true,
                      keepAll: true,
                      reportDir: './',
                      reportFiles: 'trivy-image-MEDIUM-results.html',
                      reportName: 'Trivy HTML Report'
                    )
                    publishHTML(
                      allowMissing: true,
                      alwaysLinkToLastBuild: true,
                      keepAll: true,
                      reportDir: './',
                      reportFiles: 'trivy-image-CRITICAL-results.xml',
                      reportName: 'Trivy JUnit Report'
                    )
                }
            }
        }
    }

    post {
        always {
            slackNotificationMethod(currentBuild.currentResult)
            script {
                if (fileExists('solar-system-gitops-argocd')) {
                    sh 'rm -rf solar-system-gitops-argocd'
                }
            }
            junit allowEmptyResults: true, testResults: 'test-results.xml'
            junit allowEmptyResults: true, testResults: 'dependency-check-junit.xml'
            publishHTML(
              allowMissing: true,
              alwaysLinkToLastBuild: true,
              reportDir: 'coverage/',
              reportFiles: 'lcov.info',
              reportName: 'Coverage Report'
            )
        }
    }
}

Key Pipeline Stages Summary

Stage	Purpose
Installing Dependencies	Install npm modules without audit
Dependency Scanning	Run `npm audit` in parallel
Unit Testing	Execute unit tests
Code Coverage	Generate coverage report (non-blocking)
Build Docker Image	Build container for deployment/testing
Trivy Vulnerability Scanner	Scan image, export HTML & JUnit reports

Step 4: Create a New Branch for Advanced Demos

Instead of modifying feature/enabling-slack, spin up a fresh feature branch:

git checkout -b feature/advanced-demo origin/feature/enabling-slack
git push -u origin feature/advanced-demo

Jenkins Multibranch Pipeline will auto-detect and trigger a build for the new branch.

The image shows a Jenkins dashboard displaying the status of a pipeline for a project named "feature/advanced-demo," with a build history and navigation options on the left.

Step 5: Verify in Blue Ocean

Open the Blue Ocean UI to get a visual representation of your streamlined pipeline. You should now see only the core stages instead of the full, unfiltered list.

The image shows a Jenkins interface displaying the status of different branches in a project named "solar-system" under "Gitea-Organization." Each branch has a health status, latest commit message, and completion time.

With your Jenkinsfile refactored and a dedicated branch in place, you’re all set to explore advanced pipeline features in upcoming sessions.

Shared Libraries in Jenkins

Agents and Nodes in Jenkins

Pipeline Enhancement and Caching

Pipeline Structure and Scripted vs Declarative

Jenkins Administration and Monitoring

Backup and Configuration Management

Introduction

Demo Refactor existing Jenkinsfile

Recap: Jenkins Multibranch Pipeline

Step 1: Open the Jenkinsfile in VS Code

Step 2: Extract Slack Notification Helper

Step 3: Simplify Pipeline Structure

Key Pipeline Stages Summary

Step 4: Create a New Branch for Advanced Demos

Step 5: Verify in Blue Ocean

Links and References

Watch Video

​Recap: Jenkins Multibranch Pipeline

​Step 1: Open the Jenkinsfile in VS Code

​Step 2: Extract Slack Notification Helper

​Step 3: Simplify Pipeline Structure

​Key Pipeline Stages Summary

​Step 4: Create a New Branch for Advanced Demos

​Step 5: Verify in Blue Ocean

​Links and References

Watch Video

Recap: Jenkins Multibranch Pipeline

Step 1: Open the Jenkinsfile in VS Code

Step 2: Extract Slack Notification Helper

Step 3: Simplify Pipeline Structure

Key Pipeline Stages Summary

Step 4: Create a New Branch for Advanced Demos

Step 5: Verify in Blue Ocean

Links and References