1. Create the project structure

   mkdir docker-webapp && cd docker-webapp
   mkdir app

   You’ll end up with an app/ folder for the Node server and a couple of config files at the root.

2. Write a tiny web server

   Create app/server.js:

   const http = require('http');
   const PORT = 3000;
   http
     .createServer((_req, res) => {
       res.writeHead(200, { 'Content-Type': 'text/html' });
       res.end('<h1>Hello from a container! 🐳</h1>');
     })
     .listen(PORT, () => console.log(`Listening on ${PORT}`));

   And app/package.json:

   { "name": "docker-webapp", "version": "1.0.0", "main": "server.js" }

3. Containerize the app

   Create app/Dockerfile:

   FROM node:20-alpine
   WORKDIR /app
   COPY package*.json ./
   RUN npm install --omit=dev
   COPY . .
   EXPOSE 3000
   CMD ["node", "server.js"]

   Build and test it on its own first:

   docker build -t webapp ./app
   docker run -p 3000:3000 webapp
   # visit http://localhost:3000, then Ctrl+C

4. Add an Nginx reverse proxy

   Create nginx.conf at the project root:

   events {}
   http {
     server {
       listen 80;
       location / {
         proxy_pass http://app:3000;
         proxy_set_header Host $host;
       }
     }
   }

   Note http://app:3000 — app is the service name Compose will create, and containers reach each other by service name on the shared network.

5. Orchestrate with Docker Compose

   Create docker-compose.yml at the root:

   services:
     app:
       build: ./app
     proxy:
       image: nginx:alpine
       ports:
         - "8080:80"
       volumes:
         - ./nginx.conf:/etc/nginx/nginx.conf:ro
       depends_on:
         - app

   Bring the whole stack up:

   docker compose up --build

   Open http://localhost:8080. Your request now flows browser → Nginx → Node app, across two containers on a private network Compose created for you.

6. Operate and tear down

   docker compose ps        # see both services
   docker compose logs -f   # tail combined logs
   docker compose down      # stop and remove everything

Pick one or two to deepen the learning:

• Add a third service — a Redis container — and have the Node app increment and display a visit counter.
• Add a healthcheck to the app service in Compose and watch its status.
• Use a multi-stage build to shrink the image, and compare sizes with docker images.
• Push your image to Docker Hub or GitHub Container Registry.

Capture what you tried, what broke, and the commands that fixed it in the project notes below — that write-up is where the real learning consolidates.