stevedunn / pacman-typescript

Overview

The stevedunn/pacman-typescript project employs Docker to streamline the development workflow, providing a consistent and isolated environment for the development of the application. This document outlines how Docker is utilized within the development environment, including configuration, setup, and examples.

Dockerfile Configuration

The development environment leverages a Dockerfile to specify the necessary configurations and dependencies. The following is an example of the Dockerfile used:

# Use the official Node.js image as a parent image
FROM node:14

# Set the working directory in the container
WORKDIR /usr/src/app

# Copy package.json and package-lock.json files
COPY package*.json ./

# Install project dependencies
RUN npm install

# Copy the rest of the application code
COPY . .

# Expose the port that the application will run on
EXPOSE 3000

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

Explanation of the Dockerfile

  • Base Image: The FROM node:14 directive uses the official Node.js image, providing a reliable environment for running TypeScript and JavaScript applications.

  • Working Directory: WORKDIR /usr/src/app sets the working directory for any subsequent RUN, CMD, ENTRYPOINT, COPY, and ADD instructions.

  • Dependencies Installation: The command RUN npm install installs all the dependencies as defined in the package.json file. By copying the package files before the rest of the application code, Docker can utilize its caching layers to speed up builds when dependencies do not change.

  • Application Code: The line COPY . . copies the application code into the container.

  • Port Exposure: EXPOSE 3000 makes the application accessible on port 3000, a common choice for development servers.

  • Command to Run the Application: CMD ["npm", "start"] specifies the command to run the application when the container starts.

docker-compose Configuration

To simplify the process of managing multiple containers and configurations, the project provides a docker-compose.yml file. Below is an example configuration:

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    volumes:
      - .:/usr/src/app
    ports:
      - '3000:3000'
    environment:
      - NODE_ENV=development
    command: npm run dev

Explanation of docker-compose Configuration

  • Version: The version: '3.8' line specifies the version of the Docker Compose file format being used.

  • Service Definition: Under the services directive, app defines the main application container.

  • Build Context: The build section specifies the directory context and the Dockerfile used.

  • Volume Binding: The volumes section enables live reloading by mapping the current directory (.) to the container’s working directory (/usr/src/app). This ensures that changes made on the host machine are reflected inside the container without needing to rebuild.

  • Port Mapping: The ports section maps port 3000 of the container to port 3000 of the host, facilitating access to the application from the host system.

  • Environment Variables: The environment section sets NODE_ENV to development, enabling any development-specific configurations within the application.

  • Command Override: The command command: npm run dev is specified to start the application in development mode, which could include additional tooling like hot reloading.

Build and Run the Docker Containers

After setting up the Dockerfile and docker-compose.yml, developers can build and run their Docker containers with the following commands:

  1. Build the Docker Image: 

    docker-compose build

  2. Run the Containers:

    docker-compose up

This will start the application in a new container, allowing developers to access the app via http://localhost:3000 based on the port mapping configured in docker-compose.yml.

Conclusion

The use of Docker in the stevedunn/pacman-typescript project provides a robust environment for developers to work with, ensuring consistency and ease of setup. The combination of the Dockerfile and docker-compose simplifies workflow management, enabling an efficient development process.

Source

Information regarding Docker configuration sourced from the repository context is from the stevedunn/pacman-typescript.