Lecture 8 Exercises — Continuous Integration with GitHub Actions (1-week workload)

Objective: add a working CI workflow to your sandbox that runs tests, caches dependencies, and (optionally) builds and publishes a container image. Keep a lab log (codes/lab08/lab-notebook.md) with commands, failing/passing runs, and fixes you applied.

Exercise 1 — Prep and baseline¶

1. In your sspa-sandbox, create codes/lab08/<name.surname>/ and copy your Lecture 6/7 project there (code plus tests).

2. Run the local suites (e.g., pytest -q, ctest or your C++ test binary) and note the current status in the lab log.

3. Ensure you have a clean branch dedicated to this lab; record tool versions (python --version, g++ --version, pytest --version).

Exercise 2 — Minimal CI workflow¶

1. Create .github/workflows/ci.yml under codes/lab08/<name.surname>/.

2. Add triggers on push and pull_request to main (or your branch) and a job that:

   • Checks out the repo.

   • Sets up Python (pin a version, e.g., 3.11).

   • Installs dependencies deterministically (pip install -r requirements.txt or constraints).

   • Runs your test suite (pytest -q, ctest, or both).

3. Push and confirm the workflow runs on GitHub; capture screenshots/links and log any failures and fixes.

Exercise 3 — Matrix and caching¶

1. Extend the workflow with a matrix over Python versions (e.g., 3.10–3.12) or compilers if you have C++ tests.

2. Enable caching (actions/setup-python with cache: pip or actions/cache keyed on lockfiles) to speed installs.

3. Add sensible job guards: timeout-minutes, fail-fast: false, and concurrency to avoid overlapping runs on the same branch.

4. Rerun CI and note timing improvements or cache hits in the lab log.

Exercise 4 — Artifacts and docs¶

1. Upload useful artifacts when jobs succeed or fail (use if: always()): test logs, coverage reports, or build outputs.

2. If you have docs (Sphinx/JupyterBook), add a job/step to build them with warnings-as-errors; upload the HTML as an artifact for preview.

3. Check artifact sizes and naming; keep them small and clear. Document what you uploaded and why.

Exercise 5 — Optional: container build and publish¶

1. Add steps to build a Docker image with docker/build-push-action (enable BuildKit via docker/setup-buildx-action).

2. Log in to GHCR using ${{ github.actor }} and ${{ secrets.GITHUB_TOKEN }} (ensure packages: write permissions) and push tags for main and git tags.

3. Pin action versions (e.g., @v5, @v3) and avoid leaking secrets in logs. Record image tags/digests in the lab log.

Submission checklist¶

• codes/lab08/<name.surname>/.github/workflows/ci.yml with working tests, caching, and matrix (where relevant).

• Optional container build/publish steps configured and documented.

• Artifacts configured for logs/coverage/docs where applicable.

• lab-notebook.md with CI run links/screenshots, failures, fixes, and timing notes.