🚀 Java Web Application Deployment with Jenkins & Tomcat on EC2

This project demonstrates how to deploy a simple Java web application using Jenkins and Apache Tomcat, hosted on two separate EC2 instances. The CI/CD pipeline automates code retrieval, build, and deployment using Maven and Jenkins.

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🧱 Infrastructure Overview

Component	Purpose
EC2 Instance #1	Jenkins Server (CI/CD)
EC2 Instance #2	Apache Tomcat Server

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📦 Application Repository

Source code is hosted on GitHub:
🔗 first-java-webapp

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🔧 Setup Instructions

1. Provision EC2 Instances

• Launch two Ubuntu EC2 instances.
• Assign Elastic IPs.
• Open ports:
  • Jenkins: 8080
  • Tomcat: 8080
  • SSH: 22

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2. Jenkins Setup (EC2 #1)

• Access Jenkins at http://<JENKINS_EC2_IP>:8080

• Install required plugins:

  • Git
  • Maven Integration
  • Deploy to Container

• Configure Maven under Manage Jenkins → Global Tool Configuration with name: mymaven

• Add Jenkins credentials:

  • ID: tomcat
  • Username: tomcat
  • Password: ********

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3. Tomcat Setup (EC2 #2)

🔐 Configure Remote Deployment Access

• Access Tomcat at http://<TOMCAT_EC2_IP>:8080

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🧪 Jenkins Pipeline Configuration

🔧 Jenkinsfile

pipeline {
    agent any
    tools {
        maven "mymaven"
    }
    stages {
        stage('Code from GitHub') {
            steps {
                git branch: 'main', url: 'https://github.com/nagarjuna281/first-java-webapp.git'
            }
        }
        stage('Build') {
            steps {
                sh 'mvn clean package'
            }
        }
        stage('Deploy to Tomcat') {
            steps {
                deploy adapters: [
                    tomcat9(
                        alternativeDeploymentContext: '', 
                        credentialsId: 'tomcat', 
                        path: '', 
                        url: 'http://<TOMCAT_EC2_IP>:8080'
                    )
                ], 
                contextPath: 'myapp', 
                war: 'target/*.war'
            }
        }
    }
}

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🛠️ Creating the Jenkins Pipeline Job

1. Open Jenkins dashboard.
2. Click New Item.
3. Enter a name (e.g., first-java-webapp) and select Pipeline, then click OK.
4. Scroll down to the Pipeline section.
5. Choose Pipeline script and paste the Jenkinsfile code above.
6. Click Save.
7. Click Build Now to trigger the pipeline.

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🚀 Deployment Flow

1. Jenkins pulls code from GitHub.
2. Maven builds the .war file.
3. Jenkins deploys the .war to Tomcat using the Deploy to Container plugin.

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🌐 Access the Application

Once deployed, your app will be available at:
http://<TOMCAT_EC2_IP>:8080/myapp