Containerize a Node.js application

Table of contents

Prerequisites

Before you begin, make sure the following tools are installed and available on your system:

  • You have installed the latest version of Docker Desktop.
  • You have a git client. The examples in this section use a command-line based git client, but you can use any client.

New to Docker?
Start with the Docker basics guide to get familiar with key concepts like images, containers, and Dockerfiles.

Overview

This guide walks you through the complete process of containerizing a Node.js application with Docker. You’ll learn how to create a production-ready Docker image using best practices that enhance performance, security, scalability, and operational efficiency.

By the end of this guide, you will:

  • Containerize a Node.js application using Docker.
  • Create and optimize a Dockerfile tailored for Node.js environments.
  • Use multi-stage builds to separate dependencies and reduce image size.
  • Configure the container for secure, efficient runtime using a non-root user.
  • Follow best practices for building secure, lightweight, and maintainable Docker images.

Get the sample application

Clone the sample application to use with this guide. Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the git repository:

$ git clone https://github.com/kristiyan-velkov/docker-nodejs-sample

Generate a Dockerfile

Docker provides an interactive CLI tool called docker init that helps scaffold the necessary configuration files for containerizing your application. This includes generating a Dockerfile, .dockerignore, compose.yaml, and README.Docker.md.

To begin, navigate to the root of your project directory:

$ cd docker-nodejs-sample

Then run the following command:

$ docker init

You’ll see output similar to:

Welcome to the Docker Init CLI

This utility will walk you through creating the following files with sensible defaults for your project:
  - .dockerignore
  - Dockerfile
  - compose.yaml
  - README.Docker.md

Let's get started!

The CLI will prompt you with a few questions about your app setup. For consistency, use the same responses shown in the example following when prompted:

QuestionAnswer
What application platform does your project use?Node
What version of Node do you want to use?24.11.1-alpine
Which package manager do you want to use?npm
Do you want to run "npm run build" before starting server?yes
What directory is your build output to?dist
What command do you want to use to start the app?npm run dev
What port does your server listen on?3000

After completion, your project directory will contain the following new files:

├── docker-nodejs-sample/
│ ├── Dockerfile
│ ├── .dockerignore
│ ├── compose.yaml
│ └── README.Docker.md

Create a Docker Compose file

While docker init generates a basic compose.yaml file, you'll need to create a more comprehensive configuration for this full-stack application. Replace the generated compose.yaml with a production-ready configuration.

Create a new file named compose.yml in your project root:

# ========================================
# Docker Compose Configuration
# Modern Node.js Todo Application
# ========================================

services:
  # ========================================
  # Development Service
  # ========================================
  app-dev:
    build:
      context: .
      dockerfile: Dockerfile
      target: development
    container_name: todoapp-dev
    ports:
      - '${APP_PORT:-3000}:3000' # API server
      - '${VITE_PORT:-5173}:5173' # Vite dev server
      - '${DEBUG_PORT:-9229}:9229' # Node.js debugger
    environment:
      NODE_ENV: development
      DOCKER_ENV: 'true'
      POSTGRES_HOST: db
      POSTGRES_PORT: 5432
      POSTGRES_DB: todoapp
      POSTGRES_USER: todoapp
      POSTGRES_PASSWORD: '${POSTGRES_PASSWORD:-todoapp_password}'
      ALLOWED_ORIGINS: '${ALLOWED_ORIGINS:-http://localhost:3000,http://localhost:5173}'
    volumes:
      - ./src:/app/src:ro
      - ./package.json:/app/package.json
      - ./vite.config.ts:/app/vite.config.ts:ro
      - ./tailwind.config.js:/app/tailwind.config.js:ro
      - ./postcss.config.js:/app/postcss.config.js:ro
    depends_on:
      db:
        condition: service_healthy
    develop:
      watch:
        - action: sync
          path: ./src
          target: /app/src
          ignore:
            - '**/*.test.*'
            - '**/__tests__/**'
        - action: rebuild
          path: ./package.json
        - action: sync
          path: ./vite.config.ts
          target: /app/vite.config.ts
        - action: sync
          path: ./tailwind.config.js
          target: /app/tailwind.config.js
        - action: sync
          path: ./postcss.config.js
          target: /app/postcss.config.js
    restart: unless-stopped
    networks:
      - todoapp-network

  # ========================================
  # Production Service
  # ========================================
  app-prod:
    build:
      context: .
      dockerfile: Dockerfile
      target: production
    container_name: todoapp-prod
    ports:
      - '${PROD_PORT:-8080}:3000'
    environment:
      NODE_ENV: production
      POSTGRES_HOST: db
      POSTGRES_PORT: 5432
      POSTGRES_DB: todoapp
      POSTGRES_USER: todoapp
      POSTGRES_PASSWORD: '${POSTGRES_PASSWORD:-todoapp_password}'
      ALLOWED_ORIGINS: '${ALLOWED_ORIGINS:-https://yourdomain.com}'
    depends_on:
      db:
        condition: service_healthy
    restart: unless-stopped
    deploy:
      resources:
        limits:
          memory: '${PROD_MEMORY_LIMIT:-2G}'
          cpus: '${PROD_CPU_LIMIT:-1.0}'
        reservations:
          memory: '${PROD_MEMORY_RESERVATION:-512M}'
          cpus: '${PROD_CPU_RESERVATION:-0.25}'
    security_opt:
      - no-new-privileges:true
    read_only: true
    tmpfs:
      - /tmp
    networks:
      - todoapp-network
    profiles:
      - prod

  # ========================================
  # PostgreSQL Database Service
  # ========================================
  db:
    image: postgres:16-alpine
    container_name: todoapp-db
    environment:
      POSTGRES_DB: '${POSTGRES_DB:-todoapp}'
      POSTGRES_USER: '${POSTGRES_USER:-todoapp}'
      POSTGRES_PASSWORD: '${POSTGRES_PASSWORD:-todoapp_password}'
    volumes:
      - postgres_data:/var/lib/postgresql/data
    ports:
      - '${DB_PORT:-5432}:5432'
    restart: unless-stopped
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready -U ${POSTGRES_USER:-todoapp} -d ${POSTGRES_DB:-todoapp}']
      interval: 10s
      timeout: 5s
      retries: 5
      start_period: 5s
    networks:
      - todoapp-network

# ========================================
# Volume Configuration
# ========================================
volumes:
  postgres_data:
    name: todoapp-postgres-data
    driver: local

# ========================================
# Network Configuration
# ========================================
networks:
  todoapp-network:
    name: todoapp-network
    driver: bridge

This Docker Compose configuration includes:

  • Development service (app-dev): Full development environment with hot reload, debugging support, and bind mounts
  • Production service (app-prod): Optimized production deployment with resource limits and security hardening
  • Database service (db): PostgreSQL 16 with persistent storage and health checks
  • Networking: Isolated network for secure service communication
  • Volumes: Persistent storage for database data

Create environment configuration

Create a .env file to configure your application settings:

$ cp .env.example .env

Update the .env file with your preferred settings:

# Application Configuration
NODE_ENV=development
APP_PORT=3000
VITE_PORT=5173
DEBUG_PORT=9229

# Production Configuration
PROD_PORT=8080
PROD_MEMORY_LIMIT=2G
PROD_CPU_LIMIT=1.0
PROD_MEMORY_RESERVATION=512M
PROD_CPU_RESERVATION=0.25

# Database Configuration
POSTGRES_HOST=db
POSTGRES_PORT=5432
POSTGRES_DB=todoapp
POSTGRES_USER=todoapp
POSTGRES_PASSWORD=todoapp_password
DB_PORT=5432

# Security Configuration
ALLOWED_ORIGINS=http://localhost:3000,http://localhost:5173

Build the Docker image

The default Dockerfile generated by docker init provides a reliable baseline for standard Node.js applications. However, since this project is a full-stack TypeScript application that includes both a backend API and frontend React components, the Dockerfile should be customized to better support and optimize this specific architecture.

Review the generated files

In the following step, you’ll improve the Dockerfile and configuration files by following best practices:

  • Use multi-stage builds to keep the final image clean and small
  • Improve performance and security by only including what’s needed

These updates make your app easier to deploy and faster to load.

Note

A Dockerfile is a plain text file that contains step-by-step instructions to build a Docker image. It automates packaging your application along with its dependencies and runtime environment.
For full details, see the Dockerfile reference.

Step 1: Configure the Dockerfile

Before creating a Dockerfile, you need to choose a base image. You can either use the Node.js Official Image or a Docker Hardened Image (DHI) from the Hardened Image catalog.

Choosing DHI offers the advantage of a production-ready image that is lightweight and secure. For more information, see Docker Hardened Images.

Important

This guide uses a stable Node.js LTS image tag that is considered secure when the guide is written. Because new releases and security patches are published regularly, the tag shown here may no longer be the safest option when you follow the guide. Always review the latest available image tags and select a secure, up-to-date version before building or deploying your application.

Official Node.js Docker Images: https://hub.docker.com/_/node

Docker Hardened Images (DHIs) are available for Node.js on Docker Hub. Unlike using the Docker Official Image, you must first mirror the Node.js image into your organization and then use it as your base image. Follow the instructions in the DHI quickstart to create a mirrored repository for Node.js.

Mirrored repositories must start with dhi-, for example: FROM <your-namespace>/dhi-node:<tag>. In the following Dockerfile, the FROM instruction uses <your-namespace>/dhi-node:24-alpine3.22-dev as the base image.

# ========================================
# Optimized Multi-Stage Dockerfile
# Node.js TypeScript Application (Using DHI)
# ========================================

FROM <your-namespace>/dhi-node:24-alpine3.22-dev AS base

# Set working directory
WORKDIR /app

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001 -G nodejs && \
    chown -R nodejs:nodejs /app

# ========================================
# Dependencies Stage
# ========================================
FROM base AS deps

# Copy package files
COPY package*.json ./

# Install production dependencies
RUN --mount=type=cache,target=/root/.npm,sharing=locked \
    npm ci --omit=dev && \
    npm cache clean --force

# Set proper ownership
RUN chown -R nodejs:nodejs /app

# ========================================
# Build Dependencies Stage
# ========================================
FROM base AS build-deps

# Copy package files
COPY package*.json ./

# Install all dependencies with build optimizations
RUN --mount=type=cache,target=/root/.npm,sharing=locked \
    npm ci --no-audit --no-fund && \
    npm cache clean --force

# Create necessary directories and set permissions
RUN mkdir -p /app/node_modules/.vite && \
    chown -R nodejs:nodejs /app

# ========================================
# Build Stage
# ========================================
FROM build-deps AS build

# Copy only necessary files for building (respects .dockerignore)
COPY --chown=nodejs:nodejs . .

# Build the application
RUN npm run build

# Set proper ownership
RUN chown -R nodejs:nodejs /app

# ========================================
# Development Stage
# ========================================
FROM build-deps AS development

# Set environment
ENV NODE_ENV=development \
    NPM_CONFIG_LOGLEVEL=warn

# Copy source files
COPY . .

# Ensure all directories have proper permissions
RUN mkdir -p /app/node_modules/.vite && \
    chown -R nodejs:nodejs /app && \
    chmod -R 755 /app

# Switch to non-root user
USER nodejs

# Expose ports
EXPOSE 3000 5173 9229

# Start development server
CMD ["npm", "run", "dev:docker"]

# ========================================
# Production Stage
# ========================================
FROM <your-namespace>/dhi-node:24-alpine3.22-dev AS production

# Set working directory
WORKDIR /app

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001 -G nodejs && \
    chown -R nodejs:nodejs /app

# Set optimized environment variables
ENV NODE_ENV=production \
    NODE_OPTIONS="--max-old-space-size=256 --no-warnings" \
    NPM_CONFIG_LOGLEVEL=silent

# Copy production dependencies from deps stage
COPY --from=deps --chown=nodejs:nodejs /app/node_modules ./node_modules
COPY --from=deps --chown=nodejs:nodejs /app/package*.json ./
# Copy built application from build stage
COPY --from=build --chown=nodejs:nodejs /app/dist ./dist

# Switch to non-root user for security
USER nodejs

# Expose port
EXPOSE 3000

# Start production server
CMD ["node", "dist/server.js"]

# ========================================
# Test Stage
# ========================================
FROM build-deps AS test

# Set environment
ENV NODE_ENV=test \
    CI=true

# Copy source files
COPY --chown=nodejs:nodejs . .

# Switch to non-root user
USER nodejs

# Run tests with coverage
CMD ["npm", "run", "test:coverage"]

Now you need to create a production-ready multi-stage Dockerfile. Replace the generated Dockerfile with the following optimized configuration:

# ========================================
# Optimized Multi-Stage Dockerfile
# Node.js TypeScript Application
# ========================================

ARG NODE_VERSION=24.11.1-alpine
FROM node:${NODE_VERSION} AS base

# Set working directory
WORKDIR /app

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001 -G nodejs && \
    chown -R nodejs:nodejs /app

# ========================================
# Dependencies Stage
# ========================================
FROM base AS deps

# Copy package files
COPY package*.json ./

# Install production dependencies
RUN --mount=type=cache,target=/root/.npm,sharing=locked \
    npm ci --omit=dev && \
    npm cache clean --force

# Set proper ownership
RUN chown -R nodejs:nodejs /app

# ========================================
# Build Dependencies Stage
# ========================================
FROM base AS build-deps

# Copy package files
COPY package*.json ./

# Install all dependencies with build optimizations
RUN --mount=type=cache,target=/root/.npm,sharing=locked \
    npm ci --no-audit --no-fund && \
    npm cache clean --force

# Create necessary directories and set permissions
RUN mkdir -p /app/node_modules/.vite && \
    chown -R nodejs:nodejs /app

# ========================================
# Build Stage
# ========================================
FROM build-deps AS build

# Copy only necessary files for building (respects .dockerignore)
COPY --chown=nodejs:nodejs . .

# Build the application
RUN npm run build

# Set proper ownership
RUN chown -R nodejs:nodejs /app

# ========================================
# Development Stage
# ========================================
FROM build-deps AS development

# Set environment
ENV NODE_ENV=development \
    NPM_CONFIG_LOGLEVEL=warn

# Copy source files
COPY . .

# Ensure all directories have proper permissions
RUN mkdir -p /app/node_modules/.vite && \
    chown -R nodejs:nodejs /app && \
    chmod -R 755 /app

# Switch to non-root user
USER nodejs

# Expose ports
EXPOSE 3000 5173 9229

# Start development server
CMD ["npm", "run", "dev:docker"]

# ========================================
# Production Stage
# ========================================
ARG NODE_VERSION=24.11.1-alpine
FROM node:${NODE_VERSION} AS production

# Set working directory
WORKDIR /app

# Create non-root user for security
RUN addgroup -g 1001 -S nodejs && \
    adduser -S nodejs -u 1001 -G nodejs && \
    chown -R nodejs:nodejs /app

# Set optimized environment variables
ENV NODE_ENV=production \
    NODE_OPTIONS="--max-old-space-size=256 --no-warnings" \
    NPM_CONFIG_LOGLEVEL=silent

# Copy production dependencies from deps stage
COPY --from=deps --chown=nodejs:nodejs /app/node_modules ./node_modules
COPY --from=deps --chown=nodejs:nodejs /app/package*.json ./
# Copy built application from build stage
COPY --from=build --chown=nodejs:nodejs /app/dist ./dist

# Switch to non-root user for security
USER nodejs

# Expose port
EXPOSE 3000

# Start production server
CMD ["node", "dist/server.js"]

# ========================================
# Test Stage
# ========================================
FROM build-deps AS test

# Set environment
ENV NODE_ENV=test \
    CI=true

# Copy source files
COPY --chown=nodejs:nodejs . .

# Switch to non-root user
USER nodejs

# Run tests with coverage
CMD ["npm", "run", "test:coverage"]

Key features of this Dockerfile:

  • Multi-stage structure — Separate stages for dependencies, build, development, production, and testing to keep each phase clean and efficient.
  • Lean production image — Optimized layering reduces size and keeps only what’s required to run the app.
  • Security-minded setup — Uses a dedicated non-root user and excludes unnecessary packages.
  • Performance-friendly design — Effective use of caching and well-structured layers for faster builds.
  • Clean runtime environment — Removes files not needed in production, such as docs, tests, and build caches.
  • Straightforward port usage — The app runs on port 3000 internally, exposed externally as port 8080.
  • Memory-optimized runtime — Node.js is configured to run with a smaller memory limit than the default.

Step 2: Configure the .dockerignore file

The .dockerignore file tells Docker which files and folders to exclude when building the image.

Note

This helps:

  • Reduce image size
  • Speed up the build process
  • Prevent sensitive or unnecessary files (like .env, .git, or node_modules) from being added to the final image.

To learn more, visit the .dockerignore reference.

Copy and replace the contents of your existing .dockerignore with the optimized configuration:

# Optimized .dockerignore for Node.js + React Todo App
# Based on actual project structure

# Version control
.git/
.github/
.gitignore

# Dependencies (installed in container)
node_modules/

# Build outputs (built in container)
dist/

# Environment files
.env*

# Development files
.vscode/
*.log
coverage/
.eslintcache

# OS files
.DS_Store
Thumbs.db

# Documentation
*.md
docs/

# Deployment configs
compose.yml
Taskfile.yml
nodejs-sample-kubernetes.yaml

# Non-essential configs (keep build configs)
*.config.js
!vite.config.ts
!esbuild.config.js
!tailwind.config.js
!postcss.config.js
!tsconfig.json

Step 3: Build the Node.js application image

After creating all the configuration files, your project directory should now contain all necessary Docker configuration files:

├── docker-nodejs-sample/
│ ├── Dockerfile
│ ├── .dockerignore
│ ├── compose.yml
│ └── README.Docker.md

Now you can build the Docker image for your Node.js application.

Note

The docker build command packages your application into an image using the instructions in the Dockerfile. It includes all necessary files from the current directory (called the build context).

Run the following command from the root of your project:

$ docker build --target production --tag docker-nodejs-sample .

What this command does:

  • Uses the Dockerfile in the current directory (.)
  • Targets the production stage of the multi-stage build
  • Packages the application and its dependencies into a Docker image
  • Tags the image as docker-nodejs-sample so you can reference it later

Step 4: View local images

After building your Docker image, you can check which images are available on your local machine using either the Docker CLI or Docker Desktop. Since you're already working in the terminal, use the Docker CLI.

To list all locally available Docker images, run the following command:

$ docker images

Example Output:

REPOSITORY               TAG              IMAGE ID       CREATED         SIZE
docker-nodejs-sample     latest           423525528038   14 seconds ago  237.46MB

This output provides key details about your images:

  • Repository – The name assigned to the image.
  • Tag – A version label that helps identify different builds (e.g., latest).
  • Image ID – A unique identifier for the image.
  • Created – The timestamp indicating when the image was built.
  • Size – The total disk space used by the image.

If the build was successful, you should see docker-nodejs-sample image listed.

Run the containerized application

In the previous step, you created a Dockerfile for your Node.js application and built a Docker image using the docker build command. Now it’s time to run that image in a container and verify that your application works as expected.

Inside the docker-nodejs-sample directory, run the following command in a terminal.

$ docker compose up app-dev --build

The development application will start with both servers:

For production deployment, you can use:

$ docker compose up app-prod --build

Which serves the full-stack app at http://localhost:8080 with the Express server running on port 3000 internally, mapped to port 8080 externally.

You should see a modern Todo List application with React 19 and a fully functional REST API.

Press CTRL + C in the terminal to stop your application.

Run the application in the background

You can run the application detached from the terminal by adding the -d option. Inside the docker-nodejs-sample directory, run the following command in a terminal.

$ docker compose up app-dev --build -d

Open a browser and view the application at http://localhost:3000 (API) or http://localhost:5173 (frontend). You should see the Todo application running.

To confirm that the container is running, use docker ps command:

$ docker ps

This will list all active containers along with their ports, names, and status. Look for a container exposing ports 3000, 5173, and 9229 for the development app.

Example Output:

CONTAINER ID   IMAGE                          COMMAND                  CREATED          STATUS                 PORTS                                                                                                                                   NAMES
93f3faee32c3   docker-nodejs-sample-app-dev   "docker-entrypoint.s…"   33 seconds ago   Up 31 seconds          0.0.0.0:3000->3000/tcp, [::]:3000->3000/tcp, 0.0.0.0:5173->5173/tcp, [::]:5173->5173/tcp, 0.0.0.0:9230->9229/tcp, [::]:9230->9229/tcp   todoapp-dev

Run different profiles

You can run different configurations using Docker Compose profiles:

# Run production
$ docker compose up app-prod -d

# Run tests
$ docker compose up app-test -d

To stop the application, run:

$ docker compose down
Note

For more information about Compose commands, see the Compose CLI reference.

Summary

In this guide, you learned how to containerize, build, and run a Node.js application using Docker. By following best practices, you created a secure, optimized, and production-ready setup.

What you accomplished:

  • Initialized your project using docker init to scaffold essential Docker configuration files.
  • Created a compose.yml file with development, production, and database services.
  • Set up environment configuration with a .env file for flexible deployment settings.
  • Replaced the default Dockerfile with a multi-stage build optimized for TypeScript and React.
  • Replaced the default .dockerignore file to exclude unnecessary files and keep the image clean and efficient.
  • Built your Docker image using docker build.
  • Ran the container using docker compose up, both in the foreground and in detached mode.
  • Verified that the app was running by visiting http://localhost:8080 (production) or http://localhost:3000 (development).
  • Learned how to stop the containerized application using docker compose down.

You now have a fully containerized Node.js application, running in a Docker container, and ready for deployment across any environment with confidence and consistency.

Explore official references and best practices to sharpen your Docker workflow:

Next steps

With your Node.js application now containerized, you're ready to move on to the next step.

In the next section, you'll learn how to develop your application using Docker containers, enabling a consistent, isolated, and reproducible development environment across any machine.

Use containers for Node.js development »