Building a Chatbot from Scratch: Part 6 - Deployment

The final chapter: deploying our chatbot to the world with Docker and a VPS.

Series Complete!

• [Part 1](/blog/building-chatbot-from-scratch-part-1-setup): Project setup
• [Part 2](/blog/building-chatbot-from-scratch-part-2-ui): Chat UI
• [Part 3](/blog/building-chatbot-part-3-websockets): WebSockets
• [Part 4](/blog/building-chatbot-part-4-adding-intelligence): Response logic
• [Part 5](/blog/building-chatbot-part-5-styling): Styling

Now let's deploy it.

Dockerizing

Create `Dockerfile`:

FROM node:20-alpine

WORKDIR /app

COPY package*.json ./
RUN npm ci --only=production

COPY . .

EXPOSE 3000

CMD ["node", "server/index.js"]

Create `docker-compose.yml`:

version: "3.8"
services:
  chatbot:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
    restart: unless-stopped

Build and test locally:

docker compose up --build

Setting Up the VPS

I use DigitalOcean. A $6/month droplet works fine.

SSH in and install Docker:

# Update system
apt update && apt upgrade -y

# Install Docker
curl -fsSL https://get.docker.com | sh

# Install Docker Compose
apt install docker-compose-plugin

Deploying

Option 1: Git Clone

git clone https://github.com/yourusername/chatbot.git
cd chatbot
docker compose up -d --build

Option 2: Docker Registry

Push to Docker Hub or GitHub Container Registry:

docker build -t yourusername/chatbot .
docker push yourusername/chatbot

Then on server:

docker pull yourusername/chatbot
docker run -d -p 3000:3000 yourusername/chatbot

Nginx Reverse Proxy

For a proper domain with SSL:

server {
    listen 80;
    server_name chatbot.yourdomain.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl;
    server_name chatbot.yourdomain.com;

    ssl_certificate /etc/letsencrypt/live/chatbot.yourdomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/chatbot.yourdomain.com/privkey.pem;

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
    }
}

The WebSocket headers (`Upgrade`, `Connection`) are essential for Socket.io.

SSL with Certbot

apt install certbot python3-certbot-nginx
certbot --nginx -d chatbot.yourdomain.com

Free SSL, auto-renewal.

It's Live!

Visit your domain and chat with your bot!

What We Built

From scratch:

• Real-time chat with WebSockets
• Pattern-based responses
• Clean UI with animations
• Production deployment

Full code: github.com/chrishacia/simple-chatbot

Thanks for following along! Now go build something cool.

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