# CI/CD

Automatically run tests, linting, and deployment on every push — catch problems before they reach users.

## Tools

| Platform | Trigger | Self-hosted runner |
|---|---|---|
| GitHub Actions | push, PR, schedule | yes |
| GitLab CI | push, MR, schedule | yes |
| Gitea Actions | push, PR | yes |
| Jenkins | any (webhook/poll) | yes |

CI/CD is a platform-level choice, not a language one. The pipeline calls your existing `invoke`/`make` tasks.

## Key Concepts

- **CI (Continuous Integration)** — run tests on every commit; fail fast
- **CD (Continuous Delivery/Deployment)** — automatically ship passing builds
- **Pipeline as code** — the config lives in the repo (`*.yml`), versioned alongside the code
- **Local CI first** — Docker-based local runs before pushing; remote CI is the final net, not the primary feedback loop

## GitHub Actions — Minimal Python Pipeline

```yaml
# .github/workflows/ci.yml
name: CI

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install uv && uv pip install --system -e ".[dev]"
      - run: ruff check .
      - run: mypy .
      - run: pytest
```

## GitLab CI — Equivalent

```yaml
# .gitlab-ci.yml
image: python:3.12-slim

test:
  script:
    - pip install uv && uv pip install -e ".[dev]"
    - ruff check .
    - mypy .
    - pytest
```

## Tips

- Keep pipelines fast — slow CI gets ignored
- Cache dependency installs (e.g. `actions/cache` on `~/.cache/uv`)
- Use matrix builds to test across Python/Node versions when it matters