GitHub · GH-200
Service containers, matrices, and YAML anchors
GH-200 · Lesson 3 of 16 · 20:06
YouTube loads only after you press play. This chapter opens at its timestamp in the full course. Watch on YouTube ↗
In this lesson
Prepare for the GH-200 exam (GitHub Actions). In this lesson: service containers for databases and caches (labels as host names, port mapping, health checks), matrix strategies with include, exclude, fail-fast, max-parallel, and the 256-job limit, runner images and labels (latest labels, windows-latest on Windows Server 2025, the retired Ubuntu 20.04, pinning a version, ubuntu-slim), and YAML anchors and aliases, with what to know about merge keys. Includes three original practice questions.
Preview the topics
- Contoso’s API tests run directly on an Ubuntu runner, with a PostgreSQL service container, and the tests connect to localhost on port 5432. The connection fails. What’s missing?
- Contoso’s release builds must not change tools without warning, while its nightly builds should pick up new images on their own. Which runs-on labels fit?
- In a Contoso workflow, the test-linux job defines its environment variables with an anchor named shared-vars, holding two of them, and the test-windows job uses the alias of shared-vars. What does test-windows get?