Environment Setup Guide

Environment Setup Guide

Overview

Help developers set up complete development environments from scratch. This skill provides step-by-step guidance for installing tools, configuring dependencies, setting up environment variables, and verifying the setup works correctly.

When to Use This Skill

• Use when starting a new project and need to set up the development environment
• Use when onboarding new team members to a project
• Use when switching to a new machine or operating system
• Use when troubleshooting environment-related issues
• Use when documenting setup instructions for a project
• Use when creating development environment documentation

How It Works

Step 1: Identify Requirements

I'll help you determine what needs to be installed:

• Programming language and version (Node.js, Python, Go, etc.)
• Package managers (npm, pip, cargo, etc.)
• Database systems (PostgreSQL, MongoDB, Redis, etc.)
• Development tools (Git, Docker, IDE extensions, etc.)
• Environment variables and configuration files

Step 2: Check Current Setup

Before installing anything, I'll help you check what's already installed:

# Check versions of installed tools
node --version
python --version
git --version
docker --version

Step 3: Provide Installation Instructions

I'll give platform-specific installation commands:

• macOS: Using Homebrew
• Linux: Using apt, yum, or package manager
• Windows: Using Chocolatey, Scoop, or direct installers

Step 4: Configure the Environment

Help set up:

• Environment variables (.env files)
• Configuration files (.gitconfig, .npmrc, etc.)
• IDE settings (VS Code, IntelliJ, etc.)
• Shell configuration (.bashrc, .zshrc, etc.)

Step 5: Verify Installation

Provide verification steps to ensure everything works:

• Run version checks
• Test basic commands
• Verify database connections
• Check environment variables are loaded

Examples

Example 1: Node.js Project Setup

## Setting Up Node.js Development Environment

### Prerequisites
- macOS, Linux, or Windows
- Terminal/Command Prompt access
- Internet connection

### Step 1: Install Node.js

**macOS (using Homebrew):**
\`\`\`bash
# Install Homebrew if not installed
tmpdir="$(mktemp -d)"
trap 'rm -rf "$tmpdir"' EXIT
curl -fsSLo "$tmpdir/homebrew-install.sh" https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh
cat "$tmpdir/homebrew-install.sh"  # review the full installer before executing
/bin/bash "$tmpdir/homebrew-install.sh"

# Install Node.js
brew install node
\`\`\`

**Linux (Ubuntu/Debian):**
\`\`\`bash
# Update package list
sudo apt update

# Install Node.js and npm
tmpdir="$(mktemp -d)"
trap 'rm -rf "$tmpdir"' EXIT
curl -fsSLo "$tmpdir/nodesource-setup.sh" https://deb.nodesource.com/setup_20.x
cat "$tmpdir/nodesource-setup.sh"  # review the full installer before sudo
sudo -E bash "$tmpdir/nodesource-setup.sh"
sudo apt install -y nodejs
\`\`\`

**Windows (using Chocolatey):**
\`\`\`powershell
# Install Chocolatey if not installed
Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))

# Install Node.js
choco install nodejs
\`\`\`

### Step 2: Verify Installation

\`\`\`bash
node --version  # Should show v20.x.x or higher
npm --version   # Should show 10.x.x or higher
\`\`\`

### Step 3: Install Project Dependencies

\`\`\`bash
# Clone the repository
git clone https://github.com/your-repo/project.git
cd project

# Install dependencies
npm install
\`\`\`

### Step 4: Set Up Environment Variables

Create a \`.env\` file:
\`\`\`bash
# Copy example environment file
cp .env.example .env

# Edit with your values
nano .env
\`\`\`

Example \`.env\` content:
\`\`\`
NODE_ENV=development
PORT=3000
DATABASE_URL=postgresql://localhost:5432/mydb
API_KEY=your-api-key-here
\`\`\`

### Step 5: Run the Project

\`\`\`bash
# Start development server
npm run dev

# Should see: Server running on http://localhost:3000
\`\`\`

### Troubleshooting

**Problem:** "node: command not found"
**Solution:** Restart your terminal or run \`source ~/.bashrc\` (Linux) or \`source ~/.zshrc\` (macOS)

**Problem:** "Permission denied" errors
**Solution:** Don't use sudo with npm. Fix permissions:
\`\`\`bash
mkdir ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc
source ~/.bashrc
\`\`\`

Example 2: Python Project Setup

## Setting Up Python Development Environment

### Step 1: Install Python

**macOS:**
\`\`\`bash
brew install python@3.11
\`\`\`

**Linux:**
\`\`\`bash
sudo apt update
sudo apt install python3.11 python3.11-venv python3-pip
\`\`\`

**Windows:**
\`\`\`powershell
choco install python --version=3.11
\`\`\`

### Step 2: Verify Installation

\`\`\`bash
python3 --version  # Should show Python 3.11.x
pip3 --version     # Should show pip 23.x.x
\`\`\`

### Step 3: Create Virtual Environment

\`\`\`bash
# Navigate to project directory
cd my-project

# Create virtual environment
python3 -m venv venv

# Activate virtual environment
# macOS/Linux:
source venv/bin/activate

# Windows:
venv\Scripts\activate
\`\`\`

### Step 4: Install Dependencies

\`\`\`bash
# Install from requirements.txt
pip install -r requirements.txt

# Or install packages individually
pip install flask sqlalchemy python-dotenv
\`\`\`

### Step 5: Set Up Environment Variables

Create \`.env\` file:
\`\`\`
FLASK_APP=app.py
FLASK_ENV=development
DATABASE_URL=sqlite:///app.db
SECRET_KEY=your-secret-key-here
\`\`\`

### Step 6: Run the Application

\`\`\`bash
# Run Flask app
flask run

# Should see: Running on http://127.0.0.1:5000
\`\`\`

Example 3: Docker Development Environment

## Setting Up Docker Development Environment

### Step 1: Install Docker

**macOS:**
\`\`\`bash
brew install --cask docker
# Or download Docker Desktop from docker.com
\`\`\`

**Linux:**
\`\`\`bash
# Install Docker
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh

# Add user to docker group
sudo usermod -aG docker $USER
newgrp docker
\`\`\`

**Windows:**
Download Docker Desktop from docker.com

### Step 2: Verify Installation

\`\`\`bash
docker --version        # Should show Docker version 24.x.x
docker-compose --version # Should show Docker Compose version 2.x.x
\`\`\`

### Step 3: Create docker-compose.yml

\`\`\`yaml
version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=development
      - DATABASE_URL=postgresql://postgres:password@db:5432/mydb
    volumes:
      - .:/app
      - /app/node_modules
    depends_on:
      - db

  db:
    image: postgres:15
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=password
      - POSTGRES_DB=mydb
    ports:
      - "5432:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:
\`\`\`

### Step 4: Start Services

\`\`\`bash
# Build and start containers
docker-compose up -d

# View logs
docker-compose logs -f

# Stop services
docker-compose down
\`\`\`

### Step 5: Verify Services

\`\`\`bash
# Check running containers
docker ps

# Test database connection
docker-compose exec db psql -U postgres -d mydb
\`\`\`

Best Practices

✅ Do This

• Document Everything - Write clear setup instructions
• Use Version Managers - nvm for Node, pyenv for Python
• Create .env.example - Show required environment variables
• Test on Clean System - Verify instructions work from scratch
• Include Troubleshooting - Document common issues and solutions
• Use Docker - For consistent environments across machines
• Pin Versions - Specify exact versions in package files
• Automate Setup - Create setup scripts when possible
• Check Prerequisites - List required tools before starting
• Provide Verification Steps - Help users confirm setup works

❌ Don't Do This

• Don't Assume Tools Installed - Always check and provide install instructions
• Don't Skip Environment Variables - Document all required variables
• Don't Use Sudo with npm - Fix permissions instead
• Don't Forget Platform Differences - Provide OS-specific instructions
• Don't Leave Out Verification - Always include test steps
• Don't Use Global Installs - Prefer local/virtual environments
• Don't Ignore Errors - Document how to handle common errors
• Don't Skip Database Setup - Include database initialization steps

Common Pitfalls

Problem: "Command not found" after installation

Symptoms: Installed tool but terminal doesn't recognize it Solution:

• Restart terminal or source shell config
• Check PATH environment variable
• Verify installation location

# Check PATH
echo $PATH

# Add to PATH (example)
export PATH="/usr/local/bin:$PATH"

Problem: Permission errors with npm/pip

Symptoms: "EACCES" or "Permission denied" errors Solution:

• Don't use sudo
• Fix npm permissions or use nvm
• Use virtual environments for Python

# Fix npm permissions
mkdir ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc

Problem: Port already in use

Symptoms: "Port 3000 is already in use" Solution:

• Find and kill process using the port
• Use a different port

# Find process on port 3000
lsof -i :3000

# Kill process
kill -9 <PID>

# Or use different port
PORT=3001 npm start

Problem: Database connection fails

Symptoms: "Connection refused" or "Authentication failed" Solution:

• Verify database is running
• Check connection string
• Verify credentials

# Check if PostgreSQL is running
sudo systemctl status postgresql

# Test connection
psql -h localhost -U postgres -d mydb

Setup Script Template

Create a setup.sh script to automate setup:

#!/bin/bash

echo "🚀 Setting up development environment..."

# Check prerequisites
command -v node >/dev/null 2>&1 || { echo "❌ Node.js not installed"; exit 1; }
command -v git >/dev/null 2>&1 || { echo "❌ Git not installed"; exit 1; }

echo "✅ Prerequisites check passed"

# Install dependencies
echo "📦 Installing dependencies..."
npm install

# Copy environment file
if [ ! -f .env ]; then
    echo "📝 Creating .env file..."
    cp .env.example .env
    echo "⚠️  Please edit .env with your configuration"
fi

# Run database migrations
echo "🗄️  Running database migrations..."
npm run migrate

# Verify setup
echo "🔍 Verifying setup..."
npm run test:setup

echo "✅ Setup complete! Run 'npm run dev' to start"

Related Skills

• @brainstorming - Plan environment requirements before setup
• @systematic-debugging - Debug environment issues
• @doc-coauthoring - Create setup documentation
• @git-pushing - Set up Git configuration

Additional Resources

• Node.js Installation Guide
• Python Virtual Environments
• Docker Documentation
• Homebrew (macOS)
• Chocolatey (Windows)
• nvm (Node Version Manager)
• pyenv (Python Version Manager)

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Pro Tip: Create a setup.sh or setup.ps1 script to automate the entire setup process. Test it on a clean system to ensure it works!

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.