GitHub Tutorial for Software Engineers

A comprehensive guide for using GitHub in professional software development environments.

1. Git Basics

Initial Setup

# Configure global settings
git config --global user.name "Your Name"
git config --global user.email "your.email@company.com"

# Check configuration
git config --list

Repository Operations

# Clone repository
git clone https://github.com/company/project.git

# Initialize new repository
git init
git remote add origin https://github.com/company/project.git

2. Daily Workflow

Basic Commands

# Check status
git status

# Add files
git add .                    # Add all files
git add filename.py          # Add specific file

# Commit changes
git commit -m "Add user authentication feature"

# Push changes
git push origin main

# First time push (sets up tracking)
git push -u origin main        # -u sets upstream tracking

Understanding -u Flag

The -u (or --set-upstream) flag establishes a tracking relationship:

# With -u: Sets up tracking between local and remote branch
git push -u origin main

# After tracking is set, you can use shorthand:
git push                       # Automatically pushes to tracked remote
git pull                       # Automatically pulls from tracked remote

# Check tracking relationships
git branch -vv

Pulling Updates

# Fetch and merge latest changes
git pull origin main

# Fetch without merging
git fetch origin

3. Branching Strategy

Create and Switch Branches

# Create new branch
git checkout -b feature/user-auth

# Switch to existing branch
git checkout main

# List all branches
git branch -a

# Delete branch
git branch -d feature/user-auth

Common Branch Types

• main/master - Production code
• develop - Development integration
• feature/feature-name - New features
• bugfix/bug-description - Bug fixes
• hotfix/critical-fix - Critical production fixes

4. Collaboration Workflow

Pull Requests (PRs)

# 1. Create feature branch
git checkout -b feature/new-api

# 2. Make changes and commit
git add .
git commit -m "Implement new API endpoints"

# 3. Push branch
git push origin feature/new-api

# 4. Create PR on GitHub web interface

Code Review Process

1. Create PR with clear title and description
2. Assign reviewers from your team
3. Address feedback by pushing new commits
4. Merge after approval
5. Delete branch after merging

5. Advanced Git Operations

Merge vs Rebase

# Merge (preserves commit history)
git merge feature/new-feature

# Rebase (cleaner history)
git rebase main

Stashing Changes

# Save current work temporarily
git stash

# Apply stashed changes
git stash pop

# List stashes
git stash list

Undoing Changes

# Undo last commit (keep changes)
git reset --soft HEAD~1

# Undo last commit (discard changes)
git reset --hard HEAD~1

# Revert specific commit
git revert commit-hash

6. GitHub Features

Issues and Project Management

# Reference issues in commits
git commit -m "Fix login bug - closes #123"

# Link PRs to issues
git commit -m "Add user validation - resolves #456"

GitHub Actions (CI/CD)

Create .github/workflows/ci.yml:

name: CI
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Python
        uses: actions/setup-python@v3
        with:
          python-version: '3.9'
      - name: Install dependencies
        run: pip install -r requirements.txt
      - name: Run tests
        run: pytest

7. Organization Best Practices

Commit Message Standards

# Format: type(scope): description
feat(auth): add JWT token validation
fix(api): resolve null pointer exception
docs(readme): update installation instructions
test(user): add unit tests for user service

Branch Protection Rules

• Require PR reviews before merging
• Require status checks to pass
• Restrict force pushes to main
• Delete head branches after merge

.gitignore Best Practices

# Python
__pycache__/
*.pyc
.env
venv/

# Node.js
node_modules/
npm-debug.log

# IDE
.vscode/
.idea/

# OS
.DS_Store
Thumbs.db

8. Security and Access Control

SSH Key Setup

# Generate SSH key
ssh-keygen -t ed25519 -C "your.email@company.com"

# Add to SSH agent
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

# Add public key to GitHub account
cat ~/.ssh/id_ed25519.pub

Personal Access Tokens

• Use for HTTPS authentication
• Set appropriate scopes
• Store securely (environment variables)
• Rotate regularly

9. Troubleshooting Common Issues

Merge Conflicts

# When conflict occurs
git status                   # See conflicted files
# Edit files to resolve conflicts
git add resolved-file.py
git commit -m "Resolve merge conflict"

Large File Handling

# Install Git LFS
git lfs install

# Track large files
git lfs track "*.zip"
git add .gitattributes

Repository Cleanup

# Remove untracked files
git clean -fd

# Compress repository
git gc --aggressive

10. Team Workflows

Git Flow

# Start new feature
git flow feature start new-feature

# Finish feature
git flow feature finish new-feature

# Create release
git flow release start 1.0.0

Semantic Versioning

• MAJOR.MINOR.PATCH (e.g., 2.1.3)
• Major: Breaking changes
• Minor: New features (backward compatible)
• Patch: Bug fixes

Release Management

# Create tag
git tag -a v1.0.0 -m "Release version 1.0.0"

# Push tags
git push origin --tags

# Create release on GitHub
# Use GitHub web interface or GitHub CLI

11. Monitoring and Analytics

Useful GitHub Features

• Insights: Repository traffic and contributions
• Security: Vulnerability alerts and dependency scanning
• Actions: CI/CD pipeline monitoring
• Projects: Kanban boards for task management

Git Aliases (Productivity)

# Add to ~/.gitconfig
git config --global alias.st status
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.ci commit
git config --global alias.unstage 'reset HEAD --'

12. Emergency Procedures

Hotfix Workflow

# 1. Create hotfix branch from main
git checkout main
git checkout -b hotfix/critical-security-fix

# 2. Make fix and test
git add .
git commit -m "hotfix: patch security vulnerability"

# 3. Create emergency PR
git push origin hotfix/critical-security-fix

# 4. Merge to main and develop
# 5. Tag release
git tag -a v1.0.1 -m "Hotfix release 1.0.1"

Rollback Procedures

# Revert to previous release
git checkout main
git revert commit-hash

# Force reset (use with caution)
git reset --hard previous-commit-hash
git push --force-with-lease origin main

This guide covers essential GitHub operations for professional software development. Always follow your organization's specific workflows and policies.