Mini Project 1: Multi-Pattern Containerized Web Server Deployment

This project demonstrates foundational DevOps principles by deploying an Nginx web server using three distinct, progressively complex patterns. It uses Docker, Docker Compose, Python, and LocalStack to simulate a real-world cloud environment on a local machine, showcasing a journey from basic containerization to advanced, programmatic automation.

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Core Concepts Demonstrated

• Infrastructure as Code (IaC): Implemented both declarative (Docker Compose) and imperative (Python script) approaches, highlighting the trade-offs of each.
• Containerization & Orchestration: Created custom, multi-stage Docker images and managed a multi-container application stack with Docker Compose.
• Cloud Services Simulation: Leveraged LocalStack to mimic AWS S3 for dynamic content hosting, enabling development and testing of cloud-native patterns without an AWS account.
• Automation & Scripting: Developed a Python script using the Docker SDK (docker-py) to programmatically manage the entire application lifecycle, from network creation to container provisioning and cleanup.
• Decoupled Architecture: Refactored a monolithic application into a dynamic system where the web server fetches its content from an object store (S3) on startup via a custom entrypoint script.
• Configuration Management: Utilized environment variables to pass configuration (API endpoints, credentials, bucket names) into containers, following Twelve-Factor App principles.
• Container Networking: Configured service-to-service communication between containers on a user-defined Docker network.

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Technologies Used

• Containerization: Docker, Docker Compose
• Cloud (Simulated): LocalStack (emulating AWS S3)
• Automation: Python 3, Docker SDK (docker-py), Bash Scripting
• Web Server: Nginx
• CLI Tools: AWS CLI

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Project Structure & How to Run

This repository is divided into three parts, each located in its own directory and representing a different deployment pattern.

Part 1: Basic Declarative Deployment

A simple, self-contained Nginx deployment where the website content is built directly into the Docker image.

📦 Teaches you how to build a static web server using Docker Compose only.

To Run:

cd part1-declarative-basic
docker-compose up -d

Access the site at http://localhost:8080

Part 2: Dynamic Declarative Deployment

An advanced pattern where the Nginx container is generic and dynamically fetches its index.html file from a LocalStack S3 bucket on startup.

🔁 Demonstrates dynamic content loading using S3 + environment configs.

To Run:

First, start LocalStack and provision the S3 bucket

cd part2-declarative-dynamic
docker-compose up -d localstack

Confirm LocalStack is running

docker logs -f local-aws-cloud

Wait for it to say Ready. or similar with no repeated crash logs.

ℹ️ Once LocalStack shows "Ready" in the logs, press Ctrl + C to exit log view, then proceed with the AWS CLI commands below.

Use the AWS CLI to create the bucket and upload the content

💡 Note: Ensure AWS CLI is configured with dummy credentials: Access Key ID: test, Secret Access Key: test, Region: us-east-1 You can run aws configure to set these.

aws configure
aws --endpoint-url=http://localhost:4566 s3 mb s3://my-dynamic-website-bucket
aws --endpoint-url=http://localhost:4566 s3 cp ./nginx-web/index.html s3://my-dynamic-website-bucket/

Now, start the web server, which will pull its content from S3

docker-compose up -d nginx-service

Access the site at http://localhost:8080

To stop and clean up Part 2 containers

docker-compose down

Part 3: Imperative Deployment with Python

A Python script that uses the Docker SDK to build the entire environment from scratch. This script handles network creation, container provisioning (installing Nginx inside a bare Ubuntu container), and deployment.

⚙️ Automates everything using Python + Docker SDK (full control over containers).

To Run:

cd part3-imperative-python

Install the required Python library

pip install docker

Run the deployment script

python3 deploy.py

Access the site at http://localhost:8081.

To clean up

python3 cleanup.py

Architectural Diagram (Part 2: Dynamic Deployment)

This diagram illustrates the dynamic content flow, where the Nginx container is decoupled from its content.

Troubleshooting

LocalStack crashes with /tmp/localstack error

This is a known issue on some systems (especially Windows) when mounting the host's /tmp directory into LocalStack. Fix: Use a Docker-managed named volume and set TMPDIR=/tmp/localstack-custom in your docker-compose.yml.

AWS CLI fails to connect to localhost:4566

Ensure LocalStack container is running:

docker ps
docker logs local-aws-cloud

If it’s not running, fix the volume issue or use manual method

docker run -d -e SERVICES=s3 -e TMPDIR=/tmp/localstack-custom \
  -v localstack_data:/tmp/localstack-custom -p 4566:4566 \
  --name local-aws-cloud localstack/localstack:latest

License

This project is licensed under the MIT License - see the LICENSE file for details.