Docker Essentials: A Developer's Practical Guide for 2026

13 min read Docker changed how we build and ship software. This guide covers Docker from a developer's perspective — the concepts, commands, and patterns you'll use daily. Core Concepts An image is a read-only blueprint. A container is a running instance. A Dockerfile is the recipe. A volume persists data. A network connects containers. Essential Commands docker build --tag myapp:latest . docker run --detach --name myapp --publish 3000:3000 myapp:latest docker ps docker logs --follow myapp docker exec --interactive --tty myapp sh docker stop myapp && docker rm myapp docker system prune --all --force Multi-Stage Builds Separate the build environment from the runtime for smaller, more secure images. FROM node:22-alpine AS builder WORKDIR /app COPY package.json package-lock.json ./ RUN npm ci COPY . . RUN npm run build FROM node:22-alpine AS runner WORKDIR /app ENV NODE_ENV=production COPY --from=builder /app/dist ./dist COPY --from=builder /app/package.json ./ RUN npm ci --production --i