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A Record of Introducing Docker Compose to a Docusaurus Project

This article documents the steps for introducing Docker Compose to a Docusaurus project for local development.

Background

To unify the local development environment and simplify setup, Docker Compose was introduced to a Docusaurus (v3.8.0) project. Before this, the setup involved directly installing Node.js (v22.16.0) and pnpm (v10.11.0) on each developer's local machine.

Sources​

1. Creating the Development Dockerfile (Dockerfile.dev)​

To define a Docker image specifically for local development, Dockerfile.dev was created with the following steps:

  1. File Creation A file named Dockerfile.dev was created in the project root.

  2. Specify Base Image To maintain consistency with the production Dockerfile, node:22.16.0-alpine was specified as the base image.

  3. Enable pnpm and Install Dependencies After running corepack enable pnpm, package.json and pnpm-lock.yaml are copied into the container, and all packages, including development dependencies, are installed using pnpm install --frozen-lockfile.

  4. Expose Port and Set Startup Command The default Docusaurus development port 3000 is exposed, and the startup command is set to pnpm start --host 0.0.0.0 --no-open. This allows access from outside the container while suppressing the unnecessary automatic opening of a browser.

Dockerfile.dev
# syntax=docker/dockerfile:1
FROM node:22.16.0-alpine AS development

WORKDIR /app

RUN corepack enable pnpm

COPY package.json pnpm-lock.yaml ./
RUN pnpm install --frozen-lockfile

EXPOSE 3000
CMD ["pnpm", "start", "--host", "0.0.0.0", "--no-open"]

2. Creating the Docker Compose Configuration File (docker-compose.yml)​

To define and manage the development service, docker-compose.yml was created with the following steps:

  1. File Creation A file named docker-compose.yml was created in the project root.

  2. Service Definition A development service named app was defined, with the container name set to hkdocs_dev_app. The build context was set to the project root (.), and the Dockerfile to be used was specified as Dockerfile.dev.

  3. Port Mapping Configuration The host's port 3000 is mapped to the container's port 3000.

  4. Volume Mount Configuration For source code synchronization, .:/app:cached was set. To isolate the node_modules and .docusaurus directories, /app/node_modules and /app/.docusaurus were configured as container-specific volumes.

  5. Environment Variables and Other Settings NODE_ENV=development was set. CHOKIDAR_USEPOLLING=true is prepared but commented out for cases of unstable hot reloading. For interactive execution, tty: true and stdin_open: true were set.

docker-compose.yml
version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile.dev
    container_name: hkdocs_dev_app
    ports:
      - "3000:3000"
    volumes:
      - .:/app:cached
      - /app/node_modules
      - /app/.docusaurus
    environment:
      - NODE_ENV=development
      # CHOKIDAR_USEPOLLING=true
    tty: true
    stdin_open: true

3. Updating the Docker Build Context Exclusion File (.dockerignore)​

To optimize the Docker image build efficiency and size, the .dockerignore file was updated. The main exclusions include .git, node_modules, build, .docusaurus, Docker-related files themselves, deployment scripts, environment-specific files, log files, OS-specific files, and IDE configuration files.

Note

Since pnpm-lock.yaml is used by the COPY command inside Dockerfile.dev, it is not included in the .dockerignore file.

.dockerignore
# Git
.git
.gitignore

# Node.js
node_modules

# Docusaurus build output and cache
build
.docusaurus

# Docker related files
Dockerfile
Dockerfile.dev
docker-compose.yml
docker-compose.*.yml

# Deployment scripts & environment specific files
deploy.sh
.env
*.local

# Logs
*.log
pnpm-debug.log*

# IDE/Editor specific
.DS_Store
.vscode/
.idea/

4. Using and Verifying the Development Environment​

  1. Starting the Development Environment From the terminal in the project root directory, start the development environment using docker-compose up --build for the first time or after changing configuration files. For subsequent starts, use docker-compose up.

  2. Verifying in the Browser Access http://localhost:3000 in a browser and confirm that the Docusaurus site is displayed.

  3. Testing Hot Reload Edit and save a source code file in your editor on the host machine and confirm that the changes are immediately reflected in the browser (hot reload).

    If Hot Reload is Unstable

    You can address this by uncommenting CHOKIDAR_USEPOLLING=true in docker-compose.yml, or by adding the --poll option to the CMD in Dockerfile.dev and restarting with docker-compose up --build.

  4. Stopping the Development Environment Stop the containers by pressing Ctrl + C in the terminal where the development server is running. To completely remove the containers and associated resources (like networks), run the docker-compose down command.