Modern Development¶

GitHub Actions¶

GitHub Actions is a CI/CD platform that allows you to automate build, test, and deployment pipelines directly from your repository.

Understanding GitHub Actions - Actions overview GitHub Actions Documentation - Complete reference

Core Concepts¶

Basic Workflow Structure¶

name: CI Pipeline

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Run tests
        run: npm test

Common Triggers (Events)¶

Events that Trigger Workflows - Complete trigger reference

Workflow Syntax Key Points¶

• Workflows are YAML files in .github/workflows/ directory
• Multiple workflows can exist in a single repository
• Jobs run in parallel by default
• Steps within a job run sequentially
• Use needs: to create job dependencies
• Use if: for conditional execution

Workflow Syntax - YAML reference

Runners¶

• GitHub-hosted runners - Managed by GitHub (Ubuntu, Windows, macOS)
• Self-hosted runners - Your own machines registered with GitHub
• GitHub-hosted runners provide clean environments for each job
• Self-hosted runners can access internal resources

About GitHub-Hosted Runners - Runner options

GitHub Actions Marketplace¶

• Thousands of pre-built actions created by the community
• Common actions: checkout, setup-node, cache, upload-artifact
• Can use specific versions: uses: actions/checkout@v4
• Actions can be JavaScript, Docker, or composite

GitHub Marketplace - Browse actions

Actions Usage and Billing¶

• Public repositories get unlimited free minutes
• Different runner types have different minute multipliers
• Linux: 1x, Windows: 2x, macOS: 10x

About Billing for GitHub Actions - Billing details

GitHub Codespaces¶

GitHub Codespaces provides cloud-hosted development environments that can be accessed from a browser or VS Code.

GitHub Codespaces Overview - Codespaces documentation

Key Features¶

• Instant environments - Start coding in seconds
• Browser-based - Full VS Code in your browser
• VS Code integration - Connect from local VS Code
• Pre-configured - Defined via devcontainer.json
• Port forwarding - Access running applications
• Dotfiles support - Personalize your environment
• Prebuilds - Faster start times with pre-built images

devcontainer.json¶

Configuration file that defines the development environment:

{
  "name": "My Project",
  "image": "mcr.microsoft.com/devcontainers/javascript-node:18",
  "features": {
    "ghcr.io/devcontainers/features/docker-in-docker:2": {}
  },
  "postCreateCommand": "npm install",
  "customizations": {
    "vscode": {
      "extensions": ["dbaeumer.vscode-eslint"]
    }
  },
  "forwardPorts": [3000]
}

Setting Up Your Codespace - Configuration guide

Codespaces Billing¶

• Billed for compute (per hour) and storage (per GB/month)
• Free tier includes limited hours per month
• Compute charges only while codespace is running
• Storage charges for all codespaces (running or stopped)

About Billing for Codespaces - Billing details

Codespaces vs Local Development¶

GitHub Copilot Overview¶

GitHub Copilot is an AI-powered coding assistant that helps developers write code faster.

About GitHub Copilot - Copilot overview

Features (Foundations-level knowledge)¶

• Code completion - Suggests whole lines or functions as you type
• Chat - Ask questions about code in the IDE or on GitHub.com
• Code explanations - Understand unfamiliar code
• Test generation - Help write unit tests
• Documentation - Generate docstrings and comments

Copilot Plans¶

IDE Support¶

• Visual Studio Code
• Visual Studio
• JetBrains IDEs
• Neovim
• GitHub.com (Copilot Chat)

GitHub Copilot - Copilot documentation

CI/CD Concepts¶

Continuous Integration (CI)¶

• Automatically build and test code on every push
• Catch bugs early before they reach production
• Ensure code quality through automated checks
• GitHub Actions provides built-in CI capabilities

Continuous Deployment/Delivery (CD)¶

• Continuous Delivery - Automated testing, manual deployment
• Continuous Deployment - Fully automated from commit to production
• GitHub Actions supports deployment to any platform
• Environments provide protection rules for deployments

GitHub CI/CD Best Practices¶

• Run tests on every pull request
• Use branch protection to require passing checks
• Cache dependencies for faster builds
• Use matrix strategies to test across versions
• Implement deployment environments with approvals

About Continuous Integration - CI guide

GitHub Marketplace¶

The Marketplace is where you find tools to enhance your GitHub workflow.

GitHub Marketplace - Browse Marketplace

Categories¶

• Actions - Reusable workflow components
• Apps - OAuth or GitHub Apps that integrate with GitHub

Popular Actions¶

Key Exam Points¶

• GitHub Actions workflows are YAML files in .github/workflows/
• Jobs run in parallel by default; use needs: for dependencies
• Steps run sequentially within a job
• Common triggers: push, pull_request, schedule, workflow_dispatch
• Codespaces are configured via devcontainer.json
• Codespaces charges for both compute and storage
• GitHub Copilot is AI-powered code completion (know plans, not deep features)
• CI runs tests automatically; CD deploys automatically
• GitHub-hosted runners are managed; self-hosted are your infrastructure
• Public repos get unlimited free Actions minutes
• The Marketplace provides pre-built actions and apps