Containerized Web Application with PostgreSQL

Project Overview

This project demonstrates how to design, containerize and deploy a web application using Docker.

- Backend API: Node.js + Express
- Database: PostgreSQL
- Orchestration: Docker Compose
- Networking: Docker Macvlan
- Storage: Docker Named Volume

Architecture

Client (Browser / Postman)

↓

localhost:3000 (Port Mapping)

↓

Docker Host

↓

Docker Bridge Network
(172.18.0.0/16)

↓

Backend Container (Node.js + Express)

↓

PostgreSQL Container

↓

Docker Volume (Persistent Storage)

Repository Structure

container-project/

├── backend/
│   ├── Dockerfile
│   ├── package.json
│   ├── package-lock.json
│   ├── server.js
│   └── node_modules/

├── database/
│   ├── Dockerfile
│   └── init.sql

├── docker-compose.yml
├── .dockerignore
└── README.md

Create Macvlan Network

docker network create -d macvlan \
--subnet=192.168.1.0/24 \
--gateway=192.168.1.1 \
myymacvlan

Build and Run

docker-compose up -d

Check Running Containers

docker ps

Test API

curl http://localhost:3000/users

Insert Record

curl -X POST http://localhost:3000/add \
-H "Content-Type: application/json"
-d '{"name": "Lakshita"}'

Fetch Users

curl http://localhost:3000/users

Verify Containers

sudo docker ps

Verify Network

docker network inspect mymacvlan

Verify Images

docker images

Verify Volumes

docker volume ls

Volume Persistence

Step 1 — Insert Data

curl -X POST http://localhost:3000/add

Step 2 — Retrieve Data

curl http://localhost:3000/users

Step 3 — Stop Containers

docker-compose down

Step 4 — Restart Containers

docker-compose up -d

Step 5 — Verify Persistence

curl http://localhost:3000/users

Project Summary

This project presents the design, containerization, and deployment of a multi-container web application using Docker and Docker Compose, demonstrating fundamental DevOps and containerization principles. The system consists of a Node.js and Express backend service integrated with a PostgreSQL database, each running in isolated containers to ensure modular architecture and service independence. Docker Compose is utilized for service orchestration and dependency management, while Docker networking enables seamless inter-container communication. Additionally, Docker named volumes are implemented to provide persistent storage, ensuring that database data remains intact across container restarts. The project further validates container functionality through API testing and verification of running containers, networks, images, and volumes, thereby illustrating practical concepts such as container lifecycle management, environment configuration, data persistence, and scalable application deployment within a containerized environment.