GitHub Actions Fundamentals

GitHub Actions automates CI/CD using workflows in .github/workflows/*.yml.

Core Concepts

• Workflow: Automation file triggered by events.
• Job: Group of steps running on a runner.
• Step: Command or reusable action.
• Action: Reusable task package.
• Runner: Execution environment (GitHub-hosted/self-hosted).

Best Practices

• Trigger minimally (push, pull_request, tags).
• Pin action versions.
• Use matrix builds for compatibility testing.
• Store secrets in repository/environment secrets.
• Fail fast on lint/test/security checks.