Demo Refactor existing Jenkinsfile

In this lesson, you will learn how to streamline an existing Jenkins Pipeline in preparation for advanced demonstrations. We assume you’re already familiar with Jenkins Pipeline basics. By the end, you’ll have a lean Jenkinsfile with only essential stages, organized Trivy reports, and a dedicated branch for future enhancements.

Recap of Our Jenkins Setup

First, navigate to your Jenkins dashboard. We’re using a Git Organization Folder job configured with two repositories. In the solar-system repo, we’ve been working on the feature/enabling-flag branch.

The image shows a Jenkins dashboard displaying a list of build jobs with their statuses, last success and failure times, and durations.

Inside the solar-system organization folder, multiple branches are listed. Last time, our focus was feature/enabling-flag.

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

On the Git hosting side, the repository belongs to the dasher-org organization and currently has three branches, including feature/enabling-slack.

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

Here’s the code view on the feature/enabling-slack branch, showing recent commits and file structure.

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

Editing the Jenkinsfile

Switch to your local solar-system directory and check out the feature/enabling-slack branch:

cd solar-system
git checkout feature/enabling-slack

Open Jenkinsfile in your code editor. It contains roughly 19 stages including notifications, dependency checks, testing, Docker builds, deployments, and more. For our advanced demos, we only need these stages:

Stage	Purpose	Command(s)
Installing Dependencies	Install NPM packages without audit	`npm install --no-audit`
Dependency Scanning	Run NPM audit	`npm audit --json > npm-audit-results.json`
Unit Testing	Execute unit tests	`npm test`
Code Coverage	Generate coverage reports	`npm run coverage` (Fails safe with `catchError`)
Build Docker Image	Build application container	`docker build -t siddharth67/solar-system:$GIT_COMMIT .`
Trivy Vulnerability Scan	Scan Docker image and publish HTML/JUnit reports	`trivy image …` + `trivy convert …` (see detailed snippet)

We’re removing all other stages (e.g., OWASP Dependency Check, deployment) by commenting them out. This keeps the pipeline focused and faster to iterate.

Original Notification and Pipeline Block

Below is the initial portion of the Jenkinsfile, including the Slack notification logic and full pipeline definition:

// Slack notification function
def color = '#ec2805'
def msg = "${buildStatus}: `${env.JOB_NAME} #${env.BUILD_NUMBER}:\n${env.BUILD_URL}`"
slackSend(color: color, message: msg)

pipeline {
    agent any
    environment {
        MONGO_URI        = "mongodb+srv://supercluster.d83jj.mongodb.net/superData"
        MONGO_DB_CREDS   = credentials('mongo-db-credentials')
        MONGO_USERNAME   = credentials('mongo-db-username')
        MONGO_PASSWORD   = credentials('mongo-db-password')
    }
    stages {
        // …
    }
    post {
        always {
            slackSend(color: color, message: msg)
        }
    }
}

Refactored Jenkinsfile

Comment out unused stages and update the stages block:

pipeline {
  agent any
  environment {
    MONGO_URI      = "mongodb+srv://supercluster.d83jj.mongodb.net/superData"
    MONGO_DB_CREDS = credentials('mongo-db-credentials')
  }
  options {
    timestamps()
  }

  stages {
    stage('Installing Dependencies') {
      steps {
        sh 'npm install --no-audit'
      }
    }

    stage('Dependency Scanning') {
      parallel {
        stage('NPM Dependency Audit') {
          steps {
            sh 'npm audit --json > npm-audit-results.json'
          }
        }
        // stage('OWASP Dependency Check') { … }
      }
    }

    stage('Unit Testing') {
      steps {
        sh 'npm test'
      }
    }

    stage('Code Coverage') {
      steps {
        catchError(buildResult: 'SUCCESS', message: 'Coverage thresholds failed', stageResult: 'FAILURE') {
          sh 'npm run coverage'
        }
      }
    }

    stage('Build Docker Image') {
      steps {
        sh 'docker build -t siddharth67/solar-system:$GIT_COMMIT .'
      }
    }

    stage('Trivy Vulnerability Scanner') {
      steps {
        sh '''
          trivy image siddharth67/solar-system:$GIT_COMMIT --severity LOW,MEDIUM,HIGH \
            --exit-code 0 --quiet --format json -o trivy-results.json
          trivy convert --format template \
            --template "/usr/local/share/trivy/templates/html.tpl" \
            --output trivy-results.html trivy-results.json
          trivy convert --format template \
            --template "/usr/local/share/trivy/templates/junit.tpl" \
            --output trivy-results.xml trivy-results.json
        '''
      }
      post {
        always {
          publishHTML([
            allowMissing: true,
            alwaysLinkToLastBuild: true,
            keepAll: true,
            reportDir: '.',
            reportFiles: 'trivy-results.html',
            reportName: 'Trivy HTML Report'
          ])
          junit testResults: 'trivy-results.xml', allowEmptyResults: true
        }
      }
    }
  }

  post {
    always {
      slackSend(
        color: '#ec2805', 
        message: "${currentBuild.currentResult}: ${env.JOB_NAME} #${env.BUILD_NUMBER} - ${env.BUILD_URL}"
      )
    }
  }
}

Creating a New Branch for Advanced Demos

Rather than committing directly to feature/enabling-slack, spin off a dedicated branch:

Push any local changes on feature/enabling-slack.
In your Git UI, create feature/advanced-demo from feature/enabling-slack.
Jenkins detects the new branch and automatically triggers a build.

The image shows a Jenkins dashboard displaying the status of a pipeline for a project named "feature/advanced-demo," with a build history and permalink to the last build.

Locally switch to the new branch:

git fetch origin
git checkout feature/advanced-demo

Add the refactored Jenkinsfile, commit, and push:

git add Jenkinsfile
git commit -m "Refactor pipeline for advanced demos"
git push origin feature/advanced-demo

Once pushed, Jenkins should detect feature/advanced-demo and start a new build.

Verifying the Streamlined Pipeline

Open Blue Ocean or the classic Jenkins UI to inspect your build stages. You should see only the simplified stages in sequence.

The image shows a Jenkins build pipeline interface with a build in progress. The "Installing Dependencies" stage has failed, indicated by a red error message.

The Installing Dependencies stage may fail because of the --no-audit flag. This is intentional. Subsequent Slack notifications will still provide build status updates in your channel.

Example Trivy Rate-Limit Error

When running the Trivy scanner, you might encounter a rate-limit error:

trivy image siddharth67/solar-system:$GIT_COMMIT --severity LOW,MEDIUM,HIGH ...
2024-11-10T03:23:22Z FATAL error: database download error: TOOMANYREQUESTS

We’ll cover Trivy caching and handling rate limits in future lessons. Congratulations! Your feature/advanced-demo branch now has a clean, focused Jenkins pipeline ready for advanced demos.

Watch Video

Introduction to Shared Libraries

Demo Create a Shared Library for Slack Notification

Introduction and Basics

Jenkins Setup and Interface

Extending Jenkins and Administration

Jenkins Pipelines

Automation and Security

Setting up CI Pipeline

Code Quality and Testing

Containerization and Deployment

Kubernetes and GitOps

AWS Lambda and Advanced Deployment Techniques

Jenkins Administration and Monitoring - Part 1

Shared Libraries in Jenkins

Agents and Nodes in Jenkins

Pipeline Enhancement and Caching

Pipeline Structure and Scripted vs Declarative

Jenkins Administration and Monitoring - Part 2

Backup and Configuration Management

Demo Refactor existing Jenkinsfile

Recap of Our Jenkins Setup

Editing the Jenkinsfile

Original Notification and Pipeline Block

Refactored Jenkinsfile

Creating a New Branch for Advanced Demos

Verifying the Streamlined Pipeline

Example Trivy Rate-Limit Error

Watch Video

​Recap of Our Jenkins Setup

​Editing the Jenkinsfile

​Original Notification and Pipeline Block

​Refactored Jenkinsfile

​Creating a New Branch for Advanced Demos

​Verifying the Streamlined Pipeline

​Example Trivy Rate-Limit Error

Watch Video

Recap of Our Jenkins Setup

Editing the Jenkinsfile

Original Notification and Pipeline Block

Refactored Jenkinsfile

Creating a New Branch for Advanced Demos

Verifying the Streamlined Pipeline

Example Trivy Rate-Limit Error