Deploying a Spring Boot application on an AWS EC2 instance

Deploying a Spring Boot application on an AWS EC2 instance involves several steps. Below is a comprehensive guide to get your application up and running:

1. Prepare Your Spring Boot Application

1. Build the JAR File: Use Maven or Gradle to build your Spring Boot application.

mvn clean package

This generates a target/*.jar file.

2. Test Locally: Ensure the application runs locally without issues: 

java -jar target/your-application.jar

2. Launch an EC2 Instance

1. Log in to AWS Management Console:

• Navigate to the EC2 Dashboard.

2. Launch an Instance:

• Select an AMI (Amazon Linux 2 or Ubuntu is recommended).
• Choose an instance type (t2.micro for small apps under free tier).
• Configure instance details (e.g., security group, VPC).

3. Configure Security Group:

• Open ports:

          1. 22 for SSH access.

          2. 8080 or the port your Spring Boot app listens on.

• Add rules:

          1. Source: Use your IP for SSH.

          2. Source: Public access (0.0.0.0/0) for application access or restrict it as needed.

4. Key Pair:

• Create or use an existing key pair for SSH access.

3. Connect to the EC2 Instance

1. SSH into the Instance:

ssh -i "your-key.pem" ec2-user@your-ec2-public-ip

2. Update System Packages:

sudo yum update -y

3. Install Java: If Java is not installed, install it:

sudo yum install java-11-openjdk -y
java -version

4. Transfer the Application

1. Copy the JAR File: From your local system to the EC2 instance:

scp -i "your-key.pem" target/your-application.jar ec2-user@your-ec2-public-ip:/home/ec2-user/

5. Run the Spring Boot Application

1. Start the Application:

java -jar your-application.jar

2. Access the Application:

• Open your browser and navigate to http://<ec2-public-ip>:8080.

6. Set Up as a Background Service (Optional)

To keep the application running even after you log out:

1. Install screen or nohup:

sudo yum install screen -y

2. Run with screen:

screen
java -jar your-application.jar

Detach by pressing Ctrl+A, then D.

3. Run with nohup:

nohup java -jar your-application.jar

7. Optional - Use an Application Server (NGINX)

1. Install NGINX:

sudo yum install nginx -y

2. Configure Reverse Proxy: Update /etc/nginx/nginx.conf to route traffic to your application:

server {
    listen 80;
    server_name your-ec2-public-ip;
    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

3. Restart NGINX:

sudo systemctl restart nginx

4. Access the Application: Navigate to http://<ec2-public-ip>.