GitHub Actions

What you'll learn

• Write GitHub Actions workflows with triggers, jobs, steps, runners and dependencies.
• Use matrices, expressions, contexts, outputs and conditions correctly.
• Speed up pipelines with caching, concurrency control, timeouts and path filters.
• Secure workflows with least-privilege tokens, safe handling of untrusted input, pinned actions and OIDC.
• Reuse automation with reusable workflows and composite actions, and deploy through environments.
• Catch workflow mistakes early with actionlint and debug failing runs.

Syllabus

GitHub Actions Fundamentals

1. What GitHub Actions Does
2. Anatomy of a Workflow
3. Runners

Triggers and Filters

1. Common Events
2. Branch and Path Filters
3. Scheduled Workflows

Jobs, Steps and Data Flow

1. Steps: uses and run
2. Job Dependencies With needs
3. Outputs and Artifacts

Matrices, Expressions and Conditions

1. Matrix Builds
2. Expressions and Contexts
3. Conditional Steps and Jobs

Faster, Cheaper Pipelines

1. Dependency Caching
2. Concurrency Groups
3. Timeouts, Sizing and Splitting

Securing Workflows

1. GITHUB_TOKEN Permissions
2. Script Injection From Untrusted Input
3. Pinning Third-Party Actions
4. Secrets and OIDC

Reuse and Deployment

1. Reusable Workflows
2. Composite Actions
3. Environments, Approvals and Releases

Linting, Debugging and a Checklist

1. Linting Workflows With actionlint
2. Debugging Failing Runs
3. A GitHub Actions Review Checklist