hello-world-java

Hello World Java - CI/CD Pipeline

This project demonstrates a CI/CD pipeline for a simple Java "Hello World" application using:

• Git for version control
• Maven for build automation
• Jenkins for CI/CD
• SonarQube for code quality analysis
• Docker for containerization

📌 Prerequisites

Ensure you have the following installed on your system:

• Java 17+
• Maven
• Git
• Docker
• Jenkins (with necessary plugins: Git, Maven Integration, SonarQube Scanner, Docker Pipeline)

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🚀 Step 1: Java Code and Project Setup

Create the Java Project

mkdir hello-world-java
cd hello-world-java

Initialize a Maven Project

mvn archetype:generate -DgroupId=com.example -DartifactId=hello-world-java -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

Java Source Code (src/main/java/com/example/App.java)

package com.example;
public class App {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Unit Test (src/test/java/com/example/AppTest.java)

package com.example;

import static org.junit.Assert.assertTrue;
import org.junit.Test;

public class AppTest {
    @Test
    public void testApp() {
        assertTrue(true);
    }
}

Maven Configuration (pom.xml)

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>hello-world-java</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
</project>

Build the Java Application

mvn clean package

Target Folder Explanation

After building, Maven generates the following inside the target/ directory:

• hello-world-java-1.0-SNAPSHOT.jar → The compiled Java application.
• test-classes/ → Compiled test classes.
• surefire-reports/ → Unit test reports.
• maven-archiver/ → Metadata related to the build.

---

🔧 Step 2: Set Up Git & GitHub

Initialize Git

git init
git remote add origin https://github.com/krsaeed/hello-world-java.git
git branch -M main

Add and Commit Code

git add .
git commit -m "Initial commit"

Push to GitHub

git push -u origin main

---

🛠 Step 3: Configure Jenkins Pipeline

1. Install Jenkins and required plugins: Git, Maven Integration, SonarQube Scanner, Docker Pipeline.
2. Create a new Pipeline Job in Jenkins.
3. Add the following Jenkinsfile:

pipeline {
    agent any

    tools {
        maven 'M3'  // Ensure Maven is configured in Jenkins
    }

    stages {
        stage('Clone Repository') {
            steps {
                git branch: 'main', url: 'https://github.com/krsaeed/hello-world-java.git'
            }
        }
        
        stage('Build with Maven') {
            steps {
                sh 'mvn clean package'
            }
        }

        stage('SonarQube Analysis') {
            steps {
                withCredentials([string(credentialsId: 'SONAR_TOKEN', variable: 'SONAR_TOKEN')]) {
                    sh 'mvn sonar:sonar -Dsonar.host.url=http://192.168.1.77:9000 -Dsonar.login=$SONAR_TOKEN'
                }
            }
        }

        stage('Build Docker Image') {
            steps {
                sh 'docker build -t hello-world-java .'
            }
        }

        stage('Push Docker Image') {
            steps {
                withCredentials([usernamePassword(credentialsId: 'DOCKER_HUB_PASSWORD', usernameVariable: 'DOCKER_USER', passwordVariable: 'DOCKER_PASS')]) {
                    sh 'echo "$DOCKER_PASS" | docker login -u "khalilurrahmansaeed10634" --password-stdin'
                    sh 'docker tag hello-world-java khalilurrahmansaeed10634/hello-world-java:latest'
                    sh 'docker push khalilurrahmansaeed10634/hello-world-java:latest'
                }
            }
        }

        stage('Deploy to Server') {
            steps {
                sh '''
                    docker stop hello-world-java || true
                    docker rm hello-world-java || true
                    docker run -d --name hello-world-java -p 8085:8080 khalilurrahmansaeed10634/hello-world-java:latest
                '''
            }
        }
    }
}

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🐳 Step 4: Docker Setup & Deployment

Create a Dockerfile

FROM openjdk:17
WORKDIR /app
COPY target/hello-world-java-1.0-SNAPSHOT.jar /app/app.jar
CMD ["java", "-jar", "/app/app.jar"]

Build the Docker Image

docker build -t hello-world-java .

Run the Docker Container

docker run -d --name hello-world-container -p 8080:8080 hello-world-java

Verify if the container is running:

docker ps

Check container logs:

docker logs hello-world-container

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✅ Testing the Application

Once deployed, open your browser and visit:

http://localhost:8080

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📜 License

This project is licensed under the MIT License.

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🚀 Congratulations! Your CI/CD Pipeline is Successfully Set Up! 🚀