Node.js Docker Deployment

What is Docker Deployment in Node.js?

A Docker image packages the application with its Node version and dependencies so it runs identically everywhere. A multi-stage build keeps the production image small and free of build tooling.

Docker Deployment example

FROM node:22-alpine AS deps
WORKDIR /app
COPY package*.json ./
RUN npm ci --omit=dev

FROM node:22-alpine
WORKDIR /app
ENV NODE_ENV=production
COPY --from=deps /app/node_modules ./node_modules
COPY . .
USER node                       # never run as root
EXPOSE 5000
CMD ["node", "src/index.js"]

Key points to remember

• Copy package files and install before copying source, so the dependency layer caches.
• Use an alpine or slim base image to keep the image small.
• Run as a non-root user.
• Add a .dockerignore covering node_modules, .git and .env.
• Handle SIGTERM, or docker stop kills the process abruptly.

Common mistakes with Docker Deployment

• Copying the whole project before npm ci, invalidating the cache on every code change.
• Baking secrets into the image instead of passing them at runtime.