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.

Project Links

GitHub Repository: click here

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: Global CI/CD pipeline

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

Infrastructure Setup

Prerequisites

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

Jenkins Installation

Update system packages:

sudo apt update

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

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

Create systemd service:

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

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

Enable and start Nexus:

sudo systemctl enable nexus
sudo systemctl start nexus

Get the default admin password:

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

Tomcat Installation

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

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>

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

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

Access Nexus web interface
Create Release Repository:
- Type: maven2 (hosted)
- Name: spring-petclinic-release
- Version Policy: Release
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:

Through Tomcat Manager UI:

The /spring-petclinic application should be listed as “running”
Accessing the Application:

The Spring PetClinic application interface should be accessible

Building a CI/CD Pipeline for Spring Boot application with Jenkins, SonarQube, Nexus, and Tomcat