feat: add dev container configuration for development experience

.devcontainer/Dockerfile

@@ -0,0 +1,85 @@
+# Use official VS Code devcontainer Node.js image as base (updated to Node 20 for NestJS requirements)
+FROM mcr.microsoft.com/vscode/devcontainers/typescript-node:20-bullseye
+
+# Install system dependencies and development tools
+RUN apt-get update && apt-get install -y \
+  # Build tools for native dependencies
+  build-essential \
+  python3 \
+  python3-pip \
+  # Git for version control
+  git \
+  # Utilities
+  curl \
+  wget \
+  vim \
+  nano \
+  jq \
+  sudo \
+  # Docker CLI for integration tests
+  ca-certificates \
+  gnupg \
+  lsb-release \
+  # Clean up
+  && rm -rf /var/lib/apt/lists/*
+
+# Install Docker CLI
+RUN curl -fsSL https://download.docker.com/linux/debian/gpg | gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg \
+  && echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/debian $(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null \
+  && apt-get update \
+  && apt-get install -y docker-ce-cli docker-compose-plugin \
+  && rm -rf /var/lib/apt/lists/*
+
+# Install global npm packages for development
+RUN npm install -g \
+  # TypeScript tooling
+  typescript \
+  ts-node \
+  nodemon \
+  # Testing tools
+  mocha \
+  nyc \
+  # Linting and formatting
+  eslint \
+  prettier \
+  # Development utilities
+  concurrently \
+  cross-env \
+  # Package management
+  lerna \
+  # Build tools
+  gulp-cli
+
+# Set npm configuration for NestJS
+RUN npm config set legacy-peer-deps true
+
+# Create non-root user with proper permissions
+ARG USERNAME=node
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+# Ensure node user has the correct UID/GID
+RUN groupmod --gid $USER_GID $USERNAME \
+  && usermod --uid $USER_UID --gid $USER_GID $USERNAME \
+  && chown -R $USER_UID:$USER_GID /home/$USERNAME
+
+# Add node user to docker group for Docker socket access
+RUN groupadd docker || true \
+  && usermod -aG docker $USERNAME \
+  && echo "$USERNAME ALL=(ALL) NOPASSWD:ALL" >> /etc/sudoers
+
+# Set working directory
+WORKDIR /workspace
+
+# Create node_modules directory with proper permissions as root
+RUN mkdir -p /workspace/node_modules \
+  && chown -R $USER_UID:$USER_GID /workspace
+
+# Switch to node user for development
+USER $USERNAME
+
+# Create directories for development (will be done by post-create script)
+RUN mkdir -p /home/$USERNAME/.vscode-server
+
+# Default command (will be overridden by docker-compose)
+CMD ["bash"]

.devcontainer/README.md

@@ -0,0 +1,138 @@
+# NestJS Development Container
+
+This development container provides a complete, pre-configured environment for NestJS development with all necessary dependencies, services, and VS Code extensions.
+
+## What's Included
+
+### Development Environment
+- **Node.js 20 LTS** with npm configured for legacy peer dependencies (meets requirement >= 10.13.0)
+- **TypeScript** and related development tools
+- **Docker CLI** for containerized services
+- **GitHub CLI** for seamless GitHub integration
+
+### VS Code Extensions
+- TypeScript and JavaScript language support
+- Code formatting with Prettier
+- Linting with ESLint  
+- Testing integration with Mocha
+- Docker support for container management
+- Git enhancement with GitLens
+- Markdown support for documentation
+
+### Integration Services
+- **Redis** (port 16379) - Caching and session storage
+- **NATS** (ports 14223, 16222, 18222) - Message broker with monitoring
+- **MySQL** (port 13306) - Primary database for testing
+- **MQTT/Mosquitto** (ports 11883, 19001) - IoT messaging with WebSocket support
+
+## Getting Started
+
+1. **Open in Dev Container**: VS Code will prompt to reopen in container when opening this repository
+2. **Wait for Setup**: The container will automatically install dependencies and build packages
+3. **Services will start automatically**: Integration services (Redis, NATS, etc.) start during setup
+4. **Start Development**: All services will be available and ready for development
+
+**Note**: Integration services start after the main container is ready, not during container creation. This ensures reliable startup.
+
+## Available Commands
+
+### Build and Test
+```bash
+npm run build          # Build all packages
+npm run build:prod     # Build packages near source files
+npm test               # Run unit tests  
+npm run test:integration  # Run integration tests
+npm run lint           # Run ESLint
+npm run format         # Format code with Prettier
+```
+
+### Development
+```bash
+npm run prepare        # Setup development environment
+sh scripts/prepare.sh  # Alternative: run prepare script directly
+npm start              # Start sample application
+```
+
+### Services
+```bash
+npm run test:docker:up    # Start integration services
+npm run test:docker:down  # Stop integration services
+```
+
+### Integration Testing
+```bash
+npm run test:integration    # Run integration tests
+sh scripts/run-integration.sh  # Alternative: run integration script directly
+```
+
+## Port Forwarding
+
+The following ports are automatically forwarded for easy access:
+- **3000-3010**: Sample applications
+- **8080-8082**: Additional development servers
+- **16379**: Redis
+- **14223, 16222, 18222**: NATS services
+- **11883, 19001**: MQTT services  
+- **13306**: MySQL
+
+## Troubleshooting
+
+### Permission Issues
+If you encounter permission issues:
+```bash
+sudo chown -R node:node /workspace
+```
+
+### Missing Dependencies
+If dependencies are missing:
+```bash
+npm install --legacy-peer-deps
+```
+
+### Services Not Starting
+To manually start integration services:
+```bash
+npm run test:docker:up
+```
+
+### Container Creation Issues
+If you see errors about mounting files or directories, this usually means:
+1. A file/directory referenced in docker-compose.yml doesn't exist
+2. VS Code may be trying to mount a non-existent configuration file
+
+To fix:
+1. Check that all referenced files exist
+2. Rebuild the devcontainer: `Ctrl+Shift+P` → "Dev Containers: Rebuild Container"
+
+## Container Configuration
+
+- **Base Image**: `mcr.microsoft.com/vscode/devcontainers/typescript-node:20-bullseye`
+- **User**: `node` (UID 1000)
+- **Workspace**: `/workspace`
+- **Docker**: Docker-in-Docker enabled for integration testing
+
+## Contributing
+
+This devcontainer is designed to provide a consistent development environment for all contributors. If you need additional tools or services, please update the configuration files and test thoroughly before submitting changes.
+
+### Testing the DevContainer
+
+To validate that the devcontainer works correctly, you can run:
+
+```bash
+# Quick smoke test (2-3 minutes)
+./.devcontainer/smoke-test.sh
+
+# Full validation test (5-10 minutes)  
+./.devcontainer/validate-devcontainer.sh
+```
+
+These tests verify:
+- ✅ Node.js, npm, and TypeScript are working
+- ✅ Package installation and building
+- ✅ Docker services are running
+- ✅ Unit tests can execute
+- ✅ Code quality tools (ESLint, Prettier) are functional
+- ✅ Integration test setup is ready
+
+For more information about contributing to NestJS, see [CONTRIBUTING.md](../CONTRIBUTING.md).

.devcontainer/devcontainer.json

@@ -0,0 +1,166 @@
+{
+  "name": "NestJS Development Environment",
+  "dockerComposeFile": ["docker-compose.yml"],
+  "service": "devcontainer",
+  "workspaceFolder": "/workspace",
+  "remoteUser": "node",
+  "updateRemoteUserUID": true,
+
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-vscode.vscode-typescript-next",
+        "ms-vscode.vscode-json",
+        "esbenp.prettier-vscode",
+        "dbaeumer.vscode-eslint",
+        "ms-vscode.vscode-npm-script",
+        "christian-kohler.npm-intellisense",
+        "leizongmin.node-module-intellisense",
+        "christian-kohler.path-intellisense",
+        "formulahendry.auto-rename-tag",
+        "bradlc.vscode-tailwindcss",
+        "hbenl.vscode-test-explorer",
+        "hbenl.vscode-mocha-test-adapter",
+        "ms-azuretools.vscode-docker",
+        "eamodio.gitlens",
+        "yzhang.markdown-all-in-one"
+      ],
+
+      "settings": {
+        "typescript.updateImportsOnFileMove.enabled": "always",
+        "typescript.preferences.importModuleSpecifier": "relative",
+        "typescript.suggest.autoImports": true,
+        "typescript.suggest.completeFunctionCalls": true,
+        "typescript.workspaceSymbols.scope": "allOpenProjects",
+
+        "editor.rulers": [100],
+        "editor.tabSize": 2,
+        "editor.insertSpaces": true,
+        "editor.detectIndentation": false,
+        "editor.formatOnSave": true,
+        "editor.formatOnPaste": true,
+        "editor.codeActionsOnSave": {
+          "source.fixAll.eslint": "explicit",
+          "source.organizeImports": "explicit"
+        },
+
+        "prettier.configPath": ".prettierrc",
+        "prettier.ignorePath": ".prettierignore",
+        "prettier.requireConfig": true,
+
+        "eslint.workingDirectories": [
+          "./packages",
+          "./integration",
+          "./sample"
+        ],
+        "eslint.validate": ["javascript", "typescript"],
+
+        "files.exclude": {
+          "**/node_modules": true,
+          "**/dist": true,
+          "**/.nyc_output": true,
+          "**/coverage": true
+        },
+        "search.exclude": {
+          "**/node_modules": true,
+          "**/dist": true,
+          "**/.nyc_output": true,
+          "**/coverage": true
+        },
+
+        "docker.composeCommand": "docker-compose",
+        "docker.dockerComposeDetached": true,
+        "docker.environment": {},
+        "docker.dockerPath": "docker",
+        "docker.explorerRefreshInterval": 2000,
+        "docker.showExplorer": false,
+
+        "terminal.integrated.defaultProfile.linux": "bash",
+        "terminal.integrated.env.linux": {
+          "NODE_ENV": "development"
+        },
+
+        "mochaExplorer.files": [
+          "packages/**/*.spec.ts",
+          "integration/**/*.spec.ts"
+        ],
+        "mochaExplorer.env": {
+          "NODE_ENV": "test"
+        },
+
+        "git.confirmSync": false,
+        "git.enableSmartCommit": true,
+        "git.autofetch": true,
+
+        "npm.enableRunFromFolder": true,
+        "npm.packageManager": "npm",
+        "emmet.includeLanguages": {
+          "typescript": "html",
+          "javascript": "html"
+        }
+      }
+    }
+  },
+
+  "forwardPorts": [
+    3000, 3001, 3002, 3003, 3004, 3005, 3006, 3007, 3008, 3009, 3010, 8080,
+    8081, 8082, 14223, 16222, 18222, 16379, 11883, 19001, 13306
+  ],
+
+  "portsAttributes": {
+    "3000": {
+      "label": "Main Application",
+      "onAutoForward": "notify"
+    },
+    "14223": {
+      "label": "NATS",
+      "onAutoForward": "silent"
+    },
+    "16222": {
+      "label": "NATS Cluster",
+      "onAutoForward": "silent"
+    },
+    "18222": {
+      "label": "NATS HTTP",
+      "onAutoForward": "silent"
+    },
+    "16379": {
+      "label": "Redis",
+      "onAutoForward": "silent"
+    },
+    "11883": {
+      "label": "MQTT",
+      "onAutoForward": "silent"
+    },
+    "19001": {
+      "label": "MQTT WebSocket",
+      "onAutoForward": "silent"
+    },
+    "13306": {
+      "label": "MySQL",
+      "onAutoForward": "silent"
+    }
+  },
+
+  "postCreateCommand": "bash .devcontainer/scripts/post-create.sh",
+
+  "features": {
+    "ghcr.io/devcontainers/features/docker-in-docker:2": {
+      "version": "latest",
+      "enableNonRootDocker": "true"
+    },
+    "ghcr.io/devcontainers/features/github-cli:1": {
+      "version": "latest"
+    }
+  },
+
+  "mounts": [
+    "source=/var/run/docker.sock,target=/var/run/docker-host.sock,type=bind"
+  ],
+
+  "containerEnv": {
+    "NODE_ENV": "development",
+    "npm_config_legacy_peer_deps": "true",
+    "DOCKER_HOST": "unix:///var/run/docker-host.sock"
+  }
+}