Spring Petclinic CI/CD Pipeline

This project demonstrates a CI/CD pipeline for the Spring Petclinic application using Jenkins, Maven, SonarQube, Nexus, and Tomcat. The pipeline automates building, testing, code analysis, artifact storage, and deployment using Jenkins Pipeline as Code.

📋 Table of Contents

1. Architecture
2. Technologies Stack
3. Prerequisites
4. Infrastructure Setup
5. Pipeline Stages
6. Configuration Steps
7. Jenkinsfile Explanation
8. Future Enhancements

🏗️ Architecture

The project utilizes a modular, scalable architecture with three dedicated Virtual Machines (VMs):

Components

• Jenkins VM:
  • Orchestrates the entire CI/CD pipeline
  • Runs build and test processes
  • Hosts SonarQube (running as Docker container)
  • Integrates with SonarQube and Nexus
• Nexus VM:
  • Manages and stores build artifacts
  • Provides artifact versioning and distribution
• Tomcat VM:
  • Hosts the application server
  • Receives and deploys the final WAR file

🛠️ Technologies Stack

Category	Technology
CI/CD Platform	Jenkins
Build System	Maven
Code Analysis	SonarQube
Artifact Repository	Nexus
Application Server	Tomcat
Testing Framework	JUnit
Runtime	Java 17

🔄 Pipeline Stages

The CI/CD pipeline follows these key stages:

1. Git Checkout: Clone repository from GitHub
2. Compile: Compile project using Maven
3. Test: Run unit tests
4. SonarQube Analysis: Analyze code quality
5. Build: Package application as WAR
6. Deploy to Nexus: Store artifacts
7. Copy to Tomcat: Transfer WAR to server
8. Deploy WebApp: Activate application

🔧 Infrastructure Setup

Prerequisites

• Ubuntu/Debian-based system
• Docker and Docker Compose
• Java Development Kit 17
• Maven 3.8+

Jenkins Installation

1. Update system packages:

sudo apt update

2. Install Jenkins:

sudo wget -O /usr/share/keyrings/jenkins-keyring.asc \
  https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key
echo "deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc]" \
  https://pkg.jenkins.io/debian-stable binary/ | sudo tee \
  /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt-get update
sudo apt-get install jenkins

Nexus Installation

1. Download and install Nexus:

cd /opt
wget https://download.sonatype.com/nexus/3/latest-unix.tar.gz
tar -zxvf latest-unix.tar.gz
rm latest-unix.tar.gz
sudo mv nexus-3.* nexus

2. Create systemd service:

sudo nano /etc/systemd/system/nexus.service

3. Add configuration for Nexus service:

[Unit]
Description=nexus service
After=network.target

[Service]
Type=forking
LimitNOFILE=65536
ExecStart=/opt/nexus/bin/nexus start
ExecStop=/opt/nexus/bin/nexus stop
Restart=on-abort

[Install]
WantedBy=multi-user.target

4. Enable and start Nexus:

sudo systemctl enable nexus
sudo systemctl start nexus

5. Get the default admin password:

cat /opt/nexus/sonatype-work/nexus3/admin.password

Tomcat Installation

1. Download and install Tomcat:

# Download and install Tomcat 11
wget https://dlcdn.apache.org/tomcat/tomcat-11/v11.0.2/bin/apache-tomcat-11.0.2.tar.gz

# Create service user
sudo useradd -r -m -U -d /opt/tomcat -s /bin/false tomcat

# Extract and configure
tar xzf apache-tomcat-11.0.2.tar.gz
sudo mv apache-tomcat-11.0.2/* /opt/tomcat/

# Set permissions
sudo chown -R tomcat: /opt/tomcat

2. Configure Tomcat users (/opt/tomcat/conf/tomcat-users.xml):

<tomcat-users>
    <role rolename="manager-gui" />
    <user username="manager" password="password" roles="manager-gui" />
    <role rolename="admin-gui" />
    <user username="admin" password="password" roles="manager-gui,admin-gui" />
</tomcat-users>

3. Create Tomcat service (/etc/systemd/system/tomcat.service):

[Unit]
Description=Apache Tomcat 11 Web Application Server
After=network.target
 
[Service]
Type=forking
 
User=tomcat
Group=tomcat
 
Environment="JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64"
Environment="CATALINA_HOME=/opt/tomcat"
Environment="CATALINA_BASE=/opt/tomcat"
Environment="CATALINA_PID=/opt/tomcat/temp/tomcat.pid"
Environment="CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC"
 
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh
 
[Install]
WantedBy=multi-user.target

4. Start Tomcat service:

sudo systemctl daemon-reload
sudo systemctl start tomcat
sudo systemctl status tomcat

SonarQube Setup

Create docker-compose.yaml:

services:
  sonarqube:
    image: sonarqube:lts-community
    depends_on:
      - sonar_db
    environment:
      SONAR_JDBC_URL: jdbc:postgresql://sonar_db:5432/sonar
      SONAR_JDBC_USERNAME: sonar
      SONAR_JDBC_PASSWORD: sonar
    ports:
      - "9000:9000"

  sonar_db:
    image: postgres:17.2-alpine3.21
    environment:
      POSTGRES_USER: sonar
      POSTGRES_PASSWORD: sonar
      POSTGRES_DB: sonar

⚙️ Configuration Steps

Maven Settings

Update ~/.m2/settings.xml:

<server>
    <id>deployment</id>
    <username>username</username>     <!-- Nexus username -->
    <password>password</password>     <!-- Nexus password -->
</server>

Project Configuration

Update the pom.xml with your Nexus Repository information:

<distributionManagement>
  <repository>
    <id>deployment</id>
    <name>Internal Releases</name>
    <url>http://<your-tomcat-server-ip>:8081/repository/spring-petclinic-release/</url>
  </repository>
  <snapshotRepository>
    <id>deployment</id>
    <name>Internal Snapshot Releases</name>
    <url>http://<your-tomcat-server-ip>:8081/repository/spring-petclinic-snap/</url>
  </snapshotRepository>
</distributionManagement>

Nexus Repository Configuration

1. Access Nexus web interface
2. Create Release Repository:
   • Type: maven2 (hosted)
   • Name: spring-petclinic-release
   • Version Policy: Release
3. Create Snapshot Repository:
   • Type: maven2 (hosted)
   • Name: spring-petclinic-snap
   • Version Policy: Snapshot

Jenkinsfile Environment Variables

Update the following in the Jenkinsfile:

• REMOTE_USER: Tomcat server username
• REMOTE_HOST: Tomcat server hostname
• REMOTE_PATH: Temporary file transfer location
• TOMCAT_PATH: Tomcat webapps directory
• SonarQube authentication token

📷 Deployment Verification

Nexus Repository

After successful deployment to Nexus, you should see:

• Release artifacts in the spring-petclinic-release repository:

  

• Snapshot artifacts in the spring-petclinic-snap repository:

  

Tomcat Deployment

The application deployment can be verified in two ways:

1. Through Tomcat Manager UI:

   The /spring-petclinic application should be listed as "running"

2. Accessing the Application:

   The Spring PetClinic application interface should be accessible

SonarQube Code Analysis report

🚧 Future Enhancements

• Docker containerization of all components
• Integrate additional security scanning
• Create staging and production environment deployments