Django Multi-App Deployment with AWS VPC, Bastion Host, and CI/CD (Jenkins + AWS ECR + ALB)

Overview

This project automates the deployment of a Django application with two apps (HelloWorld and MyWorld) using Jenkins, Docker, AWS Elastic Container Registry (ECR), and Application Load Balancer (ALB) for path-based routing. Additionally, it incorporates AWS VPC, a Bastion Host, and Auto Scaling to ensure a secure, scalable, and highly available infrastructure.

Architecture

• Source Code: GitHub
• CI/CD Pipeline: Jenkins
• Containerization: Docker
• Image Registry: AWS ECR
• Load Balancer: AWS ALB (Path-based routing)
• Hosting: AWS ECS (Fargate or EC2)
• Networking & Security: AWS VPC, Public & Private Subnets, NAT Gateway, Bastion Host, Security Groups

---

Setup & Deployment

1. Configure AWS VPC & Networking

• Create a VPC with CIDR block (e.g., 10.0.0.0/16).
• Create Public and Private Subnets across two Availability Zones.
• Attach an Internet Gateway (IGW) to allow public internet access.
• Deploy a NAT Gateway in the public subnet to allow private subnet instances to access the internet.
• Deploy a Bastion Host in a public subnet to provide secure SSH access to private EC2 instances.
• Set up Route Tables:
  • Public Subnet → Internet Gateway
  • Private Subnet → NAT Gateway

2. Deploy Django Multi-App Application

Django Project Setup

• Create a Django project with two apps:

  urlpatterns = [
      path('helloworld/', include('hello_world.urls')),
      path('myworld/', include('my_world.urls')),
  ]

• Implement a /health/ endpoint for ALB health checks.

Dockerize the Application

Create a Dockerfile:

FROM python:3.9
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
EXPOSE 8000

Build & run locally:

docker build -t django-app .
docker run -p 8000:8000 django-app

---

3. CI/CD Pipeline with Jenkins

Jenkinsfile

pipeline {
    agent any

    environment {
        registryCredentials = 'ecr:us-east-1:awscreds'
        appRegistryName = '302263057737.dkr.ecr.us-east-1.amazonaws.com/djangoimg'
        djangoimgRegistry = '302263057737.dkr.ecr.us-east-1.amazonaws.com'
        cluster = "django-cluster"
        service = "djangosvc"
    }

    stages {
        stage("Fetch the Code") {
            steps {
                git branch: 'main',
                    credentialsId: 'githubid',
                    url: 'https://github.com/jaikarT21/django_application.git'
            }
        }

        stage("Build the Image") {
            steps {
                script {
                    dockerImage = docker.build("${appRegistryName}:$BUILD_NUMBER", ".")
                }
            }
        }

        stage("Push the Image to ECR") {
            steps {
                script {
                    withDockerRegistry([credentialsId: registryCredentials, url: "https://${djangoimgRegistry}"]) {
                        dockerImage.push("$BUILD_NUMBER")
                        dockerImage.push("latest")
                    }
                }
            }
        }

        stage("Remove Local Docker Images") {
            steps {
                sh 'docker rmi -f $(docker images -q) || true'
            }
        }

        stage('Deploy to AWS ECS') {
            steps {
                withAWS(credentials: 'awscreds', region: 'us-east-1') {
                    sh '''
                        set -e
                        echo " Updating ECS Service..."
                        aws ecs update-service --cluster "$cluster" --service "$service" --force-new-deployment
                        echo " Waiting for deployment to complete..."
                        aws ecs wait services-stable --cluster "$cluster" --services "$service"
                        echo " Deployment successful!"
                    '''
                }
            }
        }
    }
}

---

4. Deploy to AWS

Infrastructure Setup

1. Launch EC2 Instance:
   • Install Docker, Jenkins, and AWS CLI.
   • Configure Jenkins with GitHub Webhooks for CI/CD.
2. Set up AWS ECR:
   • Create a Docker repository.
3. Run Jenkins Pipeline:
   • Jenkins will push Docker images to AWS ECR.
4. Set Up ALB & Target Groups:
   • /helloworld/* → HelloWorld Target Group
   • /myworld/* → MyWorld Target Group
5. Enable Path-Based Routing in ALB:
   • Route requests based on URL paths.

---

Testing

• Retrieve ALB DNS Name from AWS Console.
• Access applications:

  http://<ALB-DNS>/helloworld/
  http://<ALB-DNS>/myworld/
  

• Verify health checks:

  http://<ALB-DNS>/helloworld/health/
  http://<ALB-DNS>/myworld/health/
  

---

Security Considerations

• Restrict SSH access using Bastion Host.
• Use IAM roles for secure access to AWS services.
• Enable ALB health checks for monitoring application health.
• Restrict ALB to public access while keeping ECS instances private.

---

Troubleshooting

Issue	Solution
Pipeline fails?	Check Jenkins logs.
Image not in ECR?	Verify AWS CLI credentials.
App not loading?	Check ALB routing & security groups.
Health check failing?	Ensure /health/ endpoint exists.

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Conclusion

This project automates Django multi-app deployment using Jenkins, Docker, AWS ECR, and ALB with path-based routing. The AWS VPC with Bastion Host ensures security and scalability, while Auto Scaling and ECS manage application availability.