GitHub Actions Workflows

Learn what GitHub Actions is and how it runs your build: workflows, jobs, steps and runners, plus a first working pipeline you can commit today.

Understand the YAML behind a GitHub Actions workflow: events and filters, job dependencies with needs, if conditionals, contexts and expressions.

Store workflow credentials without leaking them: repository, environment and organisation scopes, log masking and why fork pull requests get no secrets.

Speed up GitHub Actions with actions/cache: write a key that hits, use restore-keys and built-in setup caching, and see why a cache can slow a build.

Move files between GitHub Actions jobs and keep build output: upload-artifact v4 behaviour, retention, the immutability change and when a cache fits better.

Run one GitHub Actions job across many versions and platforms: matrix syntax, include and exclude, fail-fast, max-parallel and avoiding a runaway matrix.

Build and push Docker images with GitHub Actions: set up Buildx, log in to GHCR or ECR, use layer caching that works, tag sensibly and build multi-arch.

Deploy to AWS from GitHub Actions without stored keys: create the OIDC provider, write the IAM trust policy claim by claim, scope sub and fix common errors.