Dev Containers in 2026: VS Code devcontainers, GitHub Codespaces, and Reproducible Dev Environments

"Works on my machine" is a solved problem. Dev Containers define the entire development environment as code — the OS, language runtime, tools, extensions, and services — so every developer on the team has an identical setup from day one, whether they're on macOS, Windows, Linux, or a browser via GitHub Codespaces.

The time investment is a few hours to configure a Dev Container properly; the payoff is every new engineer being productive on day one instead of spending two days fighting environment setup.

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Dev Container vs Docker Compose vs setup.sh

Dev Containers are Docker containers that your IDE opens as the development environment — you write and debug code inside the container, so the environment is identical for everyone.

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Basic devcontainer.json

// .devcontainer/devcontainer.json
{
  "name": "MyApp Development",

  // Use a pre-built base image or your own Dockerfile
  "image": "mcr.microsoft.com/devcontainers/typescript-node:22-bookworm",

  // Features: add tools to the base image without a custom Dockerfile
  "features": {
    // PostgreSQL client tools
    "ghcr.io/devcontainers/features/postgres-client:1": {
      "version": "17"
    },
    // AWS CLI
    "ghcr.io/devcontainers/features/aws-cli:1": {},
    // GitHub CLI
    "ghcr.io/devcontainers/features/github-cli:1": {},
    // Docker-in-Docker (to run Docker commands inside the container)
    "ghcr.io/devcontainers/features/docker-in-docker:2": {}
  },

  // VS Code extensions installed automatically
  "customizations": {
    "vscode": {
      "extensions": [
        "dbaeumer.vscode-eslint",
        "esbenp.prettier-vscode",
        "prisma.prisma",
        "bradlc.vscode-tailwindcss",
        "ms-azuretools.vscode-docker",
        "eamodio.gitlens",
        "github.copilot",
        "usernamehw.errorlens",
        "ms-vscode.vscode-typescript-next"
      ],
      "settings": {
        "editor.formatOnSave": true,
        "editor.defaultFormatter": "esbenp.prettier-vscode",
        "typescript.tsdk": "node_modules/typescript/lib",
        "eslint.validate": ["typescript", "typescriptreact"],
        "[typescript]": {
          "editor.defaultFormatter": "esbenp.prettier-vscode"
        }
      }
    }
  },

  // Port forwarding: expose container ports to host
  "forwardPorts": [3000, 3001, 5432, 6379],
  "portsAttributes": {
    "3000": { "label": "Web App", "onAutoForward": "openBrowser" },
    "3001": { "label": "API Server" },
    "5432": { "label": "PostgreSQL" },
    "6379": { "label": "Redis" }
  },

  // Run after container creation (install deps, set up DB)
  "postCreateCommand": "bash .devcontainer/post-create.sh",

  // Run after VS Code opens (start dev server)
  "postStartCommand": "docker compose up -d postgres redis mailpit",

  // Mount SSH keys and git config from host
  "mounts": [
    "source=${localEnv:HOME}/.ssh,target=/home/node/.ssh,type=bind,consistency=cached",
    "source=${localEnv:HOME}/.gitconfig,target=/home/node/.gitconfig,type=bind,consistency=cached"
  ],

  // Run as non-root user
  "remoteUser": "node",

  // Environment variables available inside container
  "remoteEnv": {
    "NODE_ENV": "development",
    "AWS_PROFILE": "myapp-dev"
  }
}

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Post-Create Script

#!/usr/bin/env bash
# .devcontainer/post-create.sh
# Runs once after container is first created

set -euo pipefail

echo "🔧 Setting up development environment..."

# Install npm dependencies
npm ci

# Set up environment file if not present
if [ ! -f .env.local ]; then
  cp .env.example .env.local
  echo "⚠️  .env.local created from example. Add secrets before starting."
fi

# Wait for PostgreSQL to be ready
echo "⏳ Waiting for PostgreSQL..."
timeout 60 bash -c '
  while ! pg_isready -h localhost -U myapp -d myapp 2>/dev/null; do
    sleep 1
  done
'

# Run database migrations
echo "🗄️  Running database migrations..."
npx prisma migrate dev --skip-generate

# Seed database
echo "🌱 Seeding database..."
npx ts-node prisma/seed.ts

# Install pre-commit hooks
echo "🪝 Installing git hooks..."
npx husky

echo "✅ Setup complete! Start developing:"
echo "   npm run dev     → http://localhost:3000"

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Docker Compose Integration

For projects with multiple services, use Docker Compose within the Dev Container:

// .devcontainer/devcontainer.json — Docker Compose variant
{
  "name": "MyApp Development",
  "dockerComposeFile": [
    "../docker-compose.yml",
    "docker-compose.dev.yml"    // Dev-specific overrides
  ],
  "service": "app",             // Which service is the dev container
  "workspaceFolder": "/workspace",

  "features": {
    "ghcr.io/devcontainers/features/github-cli:1": {}
  },

  "customizations": {
    "vscode": {
      "extensions": ["dbaeumer.vscode-eslint", "esbenp.prettier-vscode"]
    }
  },

  "postCreateCommand": "npm ci && npx prisma migrate dev",
  "forwardPorts": [3000, 5432]
}

# .devcontainer/docker-compose.dev.yml — Overrides for dev environment
services:
  app:
    build:
      context: ..
      dockerfile: .devcontainer/Dockerfile
    volumes:
      # Mount source code (not copied — edits reflected immediately)
      - ..:/workspace:cached
      # Preserve node_modules inside container (faster than host filesystem)
      - node_modules:/workspace/node_modules
    command: sleep infinity  # Keep container running; VS Code attaches
    environment:
      - NODE_ENV=development
      - DATABASE_URL=postgresql://myapp:myapp@postgres:5432/myapp
      - REDIS_URL=redis://redis:6379

volumes:
  node_modules:

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Custom Dockerfile for Complex Environments

# .devcontainer/Dockerfile
FROM mcr.microsoft.com/devcontainers/base:ubuntu-24.04

# Install Node.js 22 via nvm (matches .nvmrc)
ARG NODE_VERSION=22
RUN su vscode -c "source /usr/local/share/nvm/nvm.sh \
    && nvm install ${NODE_VERSION} \
    && nvm alias default ${NODE_VERSION}" 2>&1

# Install PostgreSQL 17 client
RUN apt-get update && apt-get install -y \
    postgresql-client-17 \
    && rm -rf /var/lib/apt/lists/*

# Install global npm tools
RUN su vscode -c "source /usr/local/share/nvm/nvm.sh \
    && npm install -g \
        typescript \
        ts-node \
        prisma \
        @railway/cli"

# Install AWS CLI v2
RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "/tmp/awscliv2.zip" \
    && unzip /tmp/awscliv2.zip -d /tmp \
    && /tmp/aws/install \
    && rm -rf /tmp/aws /tmp/awscliv2.zip

# Set default shell to zsh with oh-my-zsh (already in base image)
USER vscode

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GitHub Codespaces Configuration

Codespaces uses the same devcontainer.json — your Dev Container is automatically a Codespace. Add Codespaces-specific optimizations:

// .devcontainer/devcontainer.json — Codespaces additions
{
  // ... existing config ...

  // Machine type recommendation
  "hostRequirements": {
    "cpus": 4,
    "memory": "8gb",
    "storage": "32gb"
  },

  // Prebuild: GitHub Action caches the container build
  // Set up in repo Settings → Codespaces → Prebuild configuration
  // Reduces startup time from 3-5 min to < 30 seconds

  // Codespaces secrets (set in GitHub repo settings)
  "secrets": {
    "DATABASE_URL": {
      "description": "PostgreSQL connection string for development",
      "documentationUrl": "https://github.com/myorg/myapp/wiki/Dev-Secrets"
    }
  }
}

Prebuilds GitHub Action

# .github/workflows/codespaces-prebuild.yml
name: Codespaces Prebuild

on:
  push:
    branches: [main]
    paths:
      - '.devcontainer/**'
      - 'package-lock.json'
      - 'prisma/schema.prisma'

jobs:
  prebuild:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Trigger Codespaces prebuild
        uses: github/codespaces-prebuilds-action@v1
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

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Dev Container Features: Common Additions

// Common features to add to devcontainer.json
{
  "features": {
    // Terraform for IaC work
    "ghcr.io/devcontainers/features/terraform:1": {
      "version": "latest",
      "tflint": "latest"
    },
    // Python (for scripts and ML work alongside Node)
    "ghcr.io/devcontainers/features/python:1": {
      "version": "3.12"
    },
    // kubectl + helm for Kubernetes work
    "ghcr.io/devcontainers/features/kubectl-helm-minikube:1": {
      "version": "latest",
      "helm": "latest"
    },
    // Git LFS for large files
    "ghcr.io/devcontainers/features/git-lfs:1": {},
    // sops for encrypted secrets
    "ghcr.io/devcontainers-contrib/features/sops:1": {}
  }
}

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Onboarding Time Comparison

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Working With Viprasol

We set up Dev Container environments for engineering teams — cutting new engineer onboarding from days to minutes.

What we deliver:

• devcontainer.json configuration for your stack (Node/Python/Go/etc.)
• Docker Compose integration with all development services
• GitHub Codespaces prebuild setup for instant cloud development
• VS Code extension list and settings standardized for your team
• Post-create automation (migrations, seeding, hook installation)

→ Discuss your developer environment setup → DevOps and platform engineering

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See Also

• Engineering Onboarding: Day-1 Checklists
• Developer Experience (DX) Metrics
• CI/CD Pipeline Setup
• Docker and Container Orchestration
• Platform Engineering with Backstage