Dev Containers

Overview

Dev Containers define reproducible development environments in Docker. Open a repo in VS Code or GitHub Codespaces and get the exact same environment — tools, extensions, settings pre-installed.

Instructions

Step 1: Basic Config

// .devcontainer/devcontainer.json — Dev environment definition
{
  "name": "My Project",
  "image": "mcr.microsoft.com/devcontainers/typescript-node:20",
  "features": {
    "ghcr.io/devcontainers/features/docker-in-docker:2": {},
    "ghcr.io/devcontainers/features/github-cli:1": {}
  },
  "forwardPorts": [3000, 5432],
  "postCreateCommand": "npm install",
  "customizations": {
    "vscode": {
      "extensions": [
        "dbaeumer.vscode-eslint",
        "esbenp.prettier-vscode"
      ],
      "settings": { "editor.formatOnSave": true }
    }
  }
}

Step 2: With Database

# .devcontainer/docker-compose.yml
services:
  app:
    image: mcr.microsoft.com/devcontainers/typescript-node:20
    volumes: [../:/workspace:cached]
    command: sleep infinity
  db:
    image: postgres:16
    environment:
      POSTGRES_PASSWORD: postgres
      POSTGRES_DB: myapp
    volumes: [pgdata:/var/lib/postgresql/data]
volumes:
  pgdata:

Guidelines

• New developer: clone → open in VS Code → "Reopen in Container" → ready.
• Features marketplace adds tools without custom Dockerfiles.
• Works with GitHub Codespaces — same config, cloud-hosted.