DevOps Assignment 4 — CI/CD Pipeline with Jenkins, Docker, SonarQube & Blue-Green Deployment

Overview

This assignment builds a complete CI/CD pipeline using Jenkins and Groovy on top of the AWS infrastructure provisioned in Assignment 3. It covers Jenkins setup, declarative pipelines, shared libraries, SonarQube integration, Docker/ECR workflows, Terraform CI/CD, and Blue-Green deployments.

Task	Description	Key Technologies
Task 1	Jenkins Installation & Basic Configuration	Jenkins, Terraform, EC2
Task 2	Declarative Pipeline with Parallel Stages	Jenkinsfile, Node.js, JUnit
Task 3	Reusable Jenkins Shared Library in Groovy	Groovy, Shared Libraries
Task 4	Code Quality with SonarQube Integration	SonarQube, Code Coverage
Task 5	Docker Build, Vulnerability Scanning & ECR Push	Docker, Trivy, AWS ECR
Task 6	Terraform CI/CD Pipeline	Terraform, tfsec, Jenkins
Task 7	Blue-Green Deployment to AWS	ALB, ASG, Blue-Green

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Prerequisites

Tool	Version
Terraform	>= 1.5
AWS CLI	>= 2.0 (configured with aws configure)
Jenkins	LTS (installed via user_data)
Docker	>= 24.0
Node.js	>= 18.x (for sample app)
An AWS account with IAM permissions	—

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Project Structure

assignment-4/
├── README.md                          # This file
├── app/                               # Sample Node.js Express application
│   ├── package.json
│   ├── src/
│   │   └── app.js
│   ├── tests/
│   │   ├── unit/
│   │   │   └── app.test.js
│   │   └── integration/
│   │       └── app.integration.test.js
│   ├── Dockerfile                     # Multi-stage Dockerfile (Task 5)
│   └── .trivyignore                   # Trivy CVE ignore file (Task 5)
├── jenkins/                           # Jenkins setup documentation
│   ├── plugins.txt                    # Installed plugins list
│   ├── setup.md                       # Controller & agent setup guide
│   └── terraform/                     # Terraform for Jenkins infra
│       ├── main.tf
│       ├── variables.tf
│       ├── outputs.tf
│       └── terraform.tfvars
├── pipelines/                         # All Jenkinsfiles
│   ├── Jenkinsfile                    # Main CI/CD pipeline (Task 2)
│   ├── Jenkinsfile.infra              # Terraform CI/CD pipeline (Task 6)
│   ├── Jenkinsfile.rollback           # Manual rollback pipeline (Task 7)
│   └── Jenkinsfile.sanity             # Sanity check pipeline (Task 1)
├── shared-library/                    # Jenkins Shared Library (Task 3)
│   ├── README.md
│   ├── vars/
│   │   ├── notifySlack.groovy
│   │   ├── buildAndPushImage.groovy
│   │   └── runSonarScan.groovy
│   └── src/
│       └── org/
│           └── devops/
│               ├── NotificationService.groovy
│               └── DockerHelper.groovy
├── terraform/                         # Infrastructure Terraform (Tasks 5, 7)
│   ├── ecr.tf                         # ECR repository + lifecycle (Task 5)
│   ├── blue-green.tf                  # Blue-Green ASGs + Target Groups (Task 7)
│   ├── sonarqube.tf                   # SonarQube EC2 (Task 4)
│   ├── variables.tf
│   ├── outputs.tf
│   └── provider.tf
└── observability/                     # (Placeholder for Prometheus/Grafana if needed)
    └── notes.md

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How to Set Up

1. Jenkins Controller & Agent (Task 1)

cd jenkins/terraform
terraform init
terraform plan
terraform apply

After apply, access Jenkins at http://<CONTROLLER_PUBLIC_IP>:8080. Complete the setup wizard, install required plugins, and configure the agent node.

2. Run the Sample Application Locally

cd app
npm install
npm start          # Runs on http://localhost:3000
npm run test:unit  # Run unit tests
npm run test:int   # Run integration tests

3. Configure Jenkins Pipelines

1. Create a Multibranch Pipeline job pointing to your GitHub repo
2. Create a Pipeline job for infra-pipeline using pipelines/Jenkinsfile.infra
3. Create a Pipeline job for rollback-pipeline using pipelines/Jenkinsfile.rollback

4. Tear Down

# Destroy Blue-Green infra
cd terraform && terraform destroy

# Destroy Jenkins infra
cd jenkins/terraform && terraform destroy

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Team Contributions

Member	Tasks	Contribution
Member 1	Tasks 1, 2, 3	Jenkins setup, pipeline authoring, shared library
Member 2	Tasks 4, 5, 6, 7	SonarQube, Docker/ECR, Terraform pipeline, Blue-Green

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Important Notes

• Never commit .terraform/, *.tfstate, *.pem, .env, or AWS credentials
• All secrets are stored as Jenkins Credentials and referenced by ID
• The shared library lives in a separate repository: jenkins-shared-library
• Tag the final submission commit as assignment-4-final on the main branch