1. Home
  2. /
  3. Docker
  4. /
  5. Multi-stage Dockerfile

Multi-stage Dockerfile - Docker Typing CST Test

Loading…

Multi-stage Dockerfile — Docker Code

Shows best practices for multi-stage builds, security considerations, and optimized Node.js container deployment.

# Multi-stage Dockerfile for Node.js application
FROM node:18-alpine AS builder

# Set working directory
WORKDIR /app

# Copy package files
COPY package*.json ./

# Install dependencies
RUN npm ci --only=production

# Copy source code
COPY . .

# Build the application
RUN npm run build

# Production stage
FROM node:18-alpine AS production

# Create non-root user
RUN addgroup -g 1001 -S nodejs && \
	adduser -S nextjs -u 1001

# Set working directory
WORKDIR /app

# Copy built application from builder stage
COPY --from=builder --chown=nextjs:nodejs /app/dist ./dist
COPY --from=builder --chown=nextjs:nodejs /app/node_modules ./node_modules
COPY --from=builder --chown=nextjs:nodejs /app/package.json ./package.json

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
	CMD curl -f http://localhost:3000/health || exit 1

# Switch to non-root user
USER nextjs

# Expose port
EXPOSE 3000

# Set environment variables
ENV NODE_ENV=production
ENV PORT=3000

# Start the application
CMD ["npm", "start"]

Docker Language Guide

Docker is a platform for developing, shipping, and running applications inside lightweight, portable containers, enabling consistent environments across development, testing, and production.

Primary Use Cases

  • ▸Packaging applications with dependencies into portable containers
  • ▸Running microservices and cloud-native apps
  • ▸Continuous integration/continuous deployment (CI/CD)
  • ▸Environment standardization across development, testing, and production
  • ▸Simplifying deployment on cloud platforms or on-premises servers

Notable Features

  • ▸Lightweight containerization with OS-level isolation
  • ▸Docker images for reproducible builds
  • ▸Docker Compose for multi-container orchestration
  • ▸Integration with container registries like Docker Hub
  • ▸Networking and volume management for containers

Origin & Creator

Created by Solomon Hykes in 2013 as part of dotCloud, now maintained by Docker, Inc. and open-source community.

Industrial Note

Docker is widely used in DevOps, microservices architectures, cloud-native applications, and continuous deployment pipelines where environment consistency, scalability, and rapid delivery are essential.

Quick Explain

  • ▸Docker uses containerization to isolate applications and their dependencies from the host system.
  • ▸Supports building images with Dockerfiles and running containers from those images.
  • ▸Provides networking, storage, and orchestration primitives to manage containers.
  • ▸Integrates with CI/CD pipelines for automated builds and deployments.
  • ▸Optimizes resource utilization compared to traditional virtual machines.

Core Features

  • ▸Docker Engine - runtime for building and running containers
  • ▸Docker Images - snapshot of an app and its dependencies
  • ▸Docker Containers - running instances of images
  • ▸Dockerfile - declarative instructions to build images
  • ▸Docker Compose - define and run multi-container apps

Learning Path

  • ▸Understand containerization concepts
  • ▸Learn Docker CLI commands
  • ▸Write Dockerfiles and build images
  • ▸Use Docker Compose for multi-container apps
  • ▸Deploy and monitor containers in production

Practical Examples

  • ▸Containerize a Node.js REST API
  • ▸Run a MySQL database container and connect app
  • ▸Use Docker Compose to run web app + database
  • ▸Build multi-stage Dockerfile for optimized image
  • ▸Deploy containers to cloud platforms like AWS ECS or Azure

Comparisons

  • ▸Docker vs Virtual Machines: Docker more lightweight, faster startup, shares OS kernel
  • ▸Docker vs Podman: Podman daemonless, rootless; Docker mature ecosystem
  • ▸Docker vs LXC: Docker focused on application containers; LXC system containers
  • ▸Docker vs Kubernetes: Kubernetes orchestrates containers; Docker builds/runs them
  • ▸Docker vs Singularity: Singularity designed for HPC, Docker for general-purpose apps

Strengths

  • ▸Portability across environments
  • ▸Resource-efficient compared to VMs
  • ▸Rapid provisioning and scaling
  • ▸Simplifies CI/CD pipelines
  • ▸Strong ecosystem and community support

Limitations

  • ▸Requires learning Docker CLI and concepts
  • ▸Container isolation not as strong as full VMs for security-sensitive workloads
  • ▸Persistent storage requires careful management
  • ▸Networking between containers can be complex
  • ▸Performance overhead when running GUI or heavy I/O applications

When NOT to Use

  • ▸Applications that require full VM isolation
  • ▸Legacy software tied to specific OS configurations
  • ▸When minimal containerization overhead is unnecessary
  • ▸GUI-heavy desktop apps
  • ▸When the team lacks containerization expertise

Cheat Sheet

  • ▸docker build -t myapp . - build image
  • ▸docker run -p 8080:80 myapp - run container
  • ▸docker ps - list running containers
  • ▸docker stop <container> - stop container
  • ▸docker-compose up - start multi-container app

FAQ

  • ▸Is Docker open-source? -> Yes, Apache 2.0 license.
  • ▸Can Docker run on Windows/macOS? -> Yes, via Docker Desktop.
  • ▸Does Docker replace VMs? -> No, it complements them with lightweight containers.
  • ▸Can Docker containers communicate with each other? -> Yes, via Docker networks.
  • ▸How to persist data in Docker? -> Use volumes or bind mounts.

30-Day Skill Plan

  • ▸Week 1: Install Docker and run hello-world container
  • ▸Week 2: Write Dockerfile and build custom images
  • ▸Week 3: Use Docker Compose for multi-service apps
  • ▸Week 4: Integrate with CI/CD pipelines
  • ▸Week 5: Deploy containers to cloud and optimize performance

Final Summary

  • ▸Docker enables containerized applications for portability and consistency.
  • ▸Supports building, shipping, and running containers efficiently.
  • ▸Optimized for microservices, CI/CD, and cloud-native apps.
  • ▸Provides tooling for orchestration, networking, and storage.
  • ▸Strong ecosystem, community, and integration options.

Project Structure

  • ▸Dockerfile - defines image build steps
  • ▸docker-compose.yml - defines multi-container setups
  • ▸src/ - application source code
  • ▸configs/ - environment-specific configurations
  • ▸data/ - optional persistent volumes

Monetization

  • ▸Docker is open-source (Apache 2.0) with commercial support
  • ▸Reduces deployment friction and operational costs
  • ▸Enables rapid CI/CD for enterprise apps
  • ▸Supports multi-cloud deployments efficiently
  • ▸Enterprise Docker Enterprise adds advanced security and management features

Productivity Tips

  • ▸Use multi-stage builds for small images
  • ▸Keep containers stateless when possible
  • ▸Use volumes for persistent data
  • ▸Automate builds and deployments with CI/CD
  • ▸Regularly prune unused images and containers

Basic Concepts

  • ▸Image - immutable snapshot of an application and its dependencies
  • ▸Container - running instance of an image
  • ▸Volume - persistent storage for containers
  • ▸Network - allows communication between containers
  • ▸Dockerfile - script for building images

Official Docs

  • ▸https://docs.docker.com/
  • ▸Docker GitHub repository
  • ▸Docker community forums and tutorials

Practice Other Languages

CReactPythonC++RustTypeScriptKotlinPHPJavaC#RubyMqlCqlN1qlCypher