Docker for Developers: A Practical Guide

Containerize Your Applications

Docker has revolutionized how we develop, ship, and run applications. Let's learn the essentials every developer should know.

Your First Dockerfile

FROM node:20-alpine

WORKDIR /app

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

COPY . .

EXPOSE 3000
CMD ["node", "dist/index.js"]

Multi-Stage Builds

Reduce image size by using multi-stage builds:

FROM node:20-alpine AS builder
WORKDIR /app
COPY . .
RUN npm ci && npm run build

FROM node:20-alpine
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
CMD ["node", "dist/index.js"]

This approach can reduce your image size by 50% or more!