Automating the deployment of a Python web application using a Jenkins pipeline on AWS aims to streamline, secure, and scale the CI/CD process.

🎯 Purpose of the Use Case

1. Faster, Reliable Delivery

Automate code build, test, and deployment for faster release cycles while reducing human errors with consistent, repeatable pipelines.

2. Continuous Integration & Continuous Deployment

Automatically trigger builds when new code is pushed to GitHub/GitLab/Bitbucket, run unit/integration tests, and deploy to staging or production environments on AWS like EC2, ECS, or EKS.

3. Infrastructure as Code (IaC)

Use tools like Terraform or CloudFormation with Jenkins to deploy infrastructure consistently and reliably.

4. Scalability and High Availability

Deploy to scalable AWS infrastructure like EC2 Auto Scaling, Elastic Load Balancer, or EKS, and ensure zero-downtime updates with rolling deployments or blue/green strategies.

5. Security and Compliance

Automate security checks like linting and SAST, and control access using Jenkins credentials and AWS IAM roles.

6. Feedback and Monitoring

Jenkins can integrate with tools like Slack, email, or JIRA for notifications, and application monitoring can be done using CloudWatch, New Relic, or DataDog.

Prerequisites :

- Python web app (Flask/Django/FastAPI)
  - AWS EC2 (or ECS/EKS for container-based deployment)
  - Jenkins installed and configured (on EC2 or externally)
  - Docker installed (if containerizing)
  - Git repository (GitHub, GitLab, etc.)

📌 Create EC2 instance on AWS console

📌Install Java 17 on the EC2 instance.

sudo apt update 
sudo apt install openjdk-17-jdk -y java -version

📌Install Jenkins on the EC2 instance.

sudo apt update 
sudo apt install openjdk-17-jdk -y wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | sudo tee /usr/share/keyrings/jenkins-keyring.asc > /dev/null 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 update sudo apt install jenkins -y 
sudo systemctl enable jenkins 
sudo systemctl start jenkins
sudo systemctl status Jenkins

📌To access Jenkins, open a web browser and go to http://your-ec2-instance-public-ip:8080.

1. Open a web browser and navigate.

http://your-server-ip:8080

2. Retrieve the initial Jenkins password.

sudo cat /var/lib/jenkins/secrets/initialAdminPassword

📌 Install Docker on EC2

Docker installation steps - follow this article

📌 Jenkins Pipeline Project Create

1. Open Jenkins Dashboard.→ Click on New Item → 3. Enter a name for your pipeline project (e.g., Fintracking_Pipeline). → 4. Select Pipeline as the project type. → 5.Click OK. → 6. Scroll down to the Pipeline section.→7. In the Definition dropdown, select Pipeline script.

Paste the Jenkins Pipeline Script (given above) into the script textbox.

pipeline {
    agent any

    environment {
        APP_NAME       = "fintrack_app"
        CONTAINER_NAME = "${APP_NAME}_container"
        APP_PORT       = "5001"
        IMAGE_TAG      = "${env.BUILD_NUMBER}"
    }

    stages {
        stage('Clean Workspace') {
            steps {
                cleanWs()
            }
        }

        stage('Clone Code') {
            steps {
                git branch: 'main', url: 'https://github.com/Ankita2295/FinancesTrackProject_Live'
            }
        }

        stage('Build Docker Image') {
            steps {
                script {
                    sh "docker build -t ${APP_NAME}:${IMAGE_TAG} ."
                }
            }
        }

        stage('Stop & Remove Existing Container') {
            steps {
                script {
                    sh """
                        docker stop ${CONTAINER_NAME} || true
                        docker rm ${CONTAINER_NAME} || true
                    """
                }
            }
        }

        stage('Run Docker Container') {
            steps {
                script {
                    sh "docker run -d -p 8080:80 ${APP_NAME}:${IMAGE_TAG} --name ${CONTAINER_NAME}"
                }
            }
        }
    }

    post {
        always {
            echo "Build for ${APP_NAME} finished. Container: ${CONTAINER_NAME}"
        }
    }
}

Save and build the pipeline.

📌 Once the Docker container is running, you can access the application.

Open your browser and go to http://EC2-public Ip:5001 to access your app.

Some Screenshot glimpse :