Github Actions

---
name: github-actions
description: >
  Use this skill when authoring or debugging GitHub Actions workflows
  (.github/workflows/*.yml) — e.g. "add CI for this Drupal project on
  GitHub", "run phpcs/phpstan/phpunit on pull requests", "cache composer
  dependencies", "deploy over SSH when main is pushed", "why didn't my
  workflow trigger", or anything involving jobs, matrices, runners, secrets,
  or reusable workflows.
---

# GitHub Actions Skill

GitHub Actions runs workflows from `.github/workflows/*.yml`. This skill
covers workflow authoring with a Drupal project as the working example:
linting, static analysis, PHPUnit with a database service, and SSH/drush
deployment.

---

## Workflow anatomy

```yaml
name: CI

on:
  pull_request:
  push:
    branches: [main]

permissions:
  contents: read            # least privilege — grant more only per job

concurrency:
  group: ci-${{ github.ref }}
  cancel-in-progress: true  # newer push cancels the outdated run

jobs:
  phpcs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with:
          php-version: '8.3'
          tools: composer:v2
      - uses: actions/cache@v4
        with:
          path: ~/.composer/cache
          key: composer-${{ hashFiles('composer.lock') }}
          restore-keys: composer-
      - run: composer install --no-progress
      - run: vendor/bin/phpcs --standard=Drupal,DrupalPractice web/modules/custom
```

Key defaults to always set:

- **`permissions:`** — the implicit token is powerful; start from
  `contents: read` and widen per job only when needed.
- **`concurrency:`** — avoids burning runner minutes on superseded pushes.

---

## PHPUnit with a database service

```yaml
  phpunit:
    runs-on: ubuntu-latest
    services:
      db:
        image: mariadb:11.4
        env:
          MARIADB_DATABASE: drupal_test
          MARIADB_ROOT_PASSWORD: root
        ports: ['3306:3306']
        options: >-
          --health-cmd="healthcheck.sh --connect --innodb_initialized"
          --health-interval=10s --health-timeout=5s --health-retries=5
    env:
      SIMPLETEST_DB: mysql://root:root@127.0.0.1:3306/drupal_test
      SIMPLETEST_BASE_URL: http://localhost
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with:
          php-version: '8.3'
          extensions: gd, pdo_mysql
      - run: composer install --no-progress
      - run: vendor/bin/phpunit -c web/core/phpunit.xml.dist web/modules/custom
```

`services:` containers get health-checked before steps run — no manual
wait loops. From the runner they are reachable on `127.0.0.1:<mapped port>`.

### Matrix builds

```yaml
    strategy:
      matrix:
        php: ['8.3', '8.4']
    steps:
      - uses: shivammathur/setup-php@v2
        with:
          php-version: ${{ matrix.php }}
```

---

## Deployment job

```yaml
  deploy:
    if: github.ref == 'refs/heads/main' && github.event_name == 'push'
    needs: [phpcs, phpunit]
    runs-on: ubuntu-latest
    environment:
      name: production
      url: https://www.example.com
    steps:
      - uses: webfactory/ssh-agent@v0.9.0
        with:
          ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
      - run: |
          ssh -o StrictHostKeyChecking=accept-new deploy@prod.example.com \
            "cd /var/www/site && git pull --ff-only \
             && composer install --no-dev --optimize-autoloader \
             && vendor/bin/drush deploy -y"
```

- `needs:` gates deployment on green checks.
- `environment:` enables required reviewers and deployment history
  (Settings → Environments) — use it for production approval gates.
- Secrets live in repo/environment settings, referenced via
  `${{ secrets.NAME }}`. For cloud providers prefer **OIDC**
  (`permissions: id-token: write` + the provider's auth action) over
  long-lived keys.

---

## Reuse

- **Reusable workflow** — a whole workflow callable from others:

  ```yaml
  # .github/workflows/drupal-tests.yml
  on:
    workflow_call:
      inputs:
        php-version: { type: string, default: '8.3' }
  ```

  ```yaml
  # caller
  jobs:
    tests:
      uses: ./.github/workflows/drupal-tests.yml
      with:
        php-version: '8.4'
  ```

- **Composite action** — a reusable step sequence in
  `.github/actions/<name>/action.yml` (e.g. "setup PHP + composer install
  with cache") to deduplicate job boilerplate.

---

## Troubleshooting

| Symptom | Fix |
|---|---|
| Workflow doesn't trigger | Check `on:` filters — `branches:`/`paths:` excluded the ref, or push was from a workflow using the default token (no recursive triggers) |
| `Permission denied` on push/comment from job | Widen `permissions:` for that job (e.g. `pull-requests: write`) |
| Composer cache never hits | Key on `hashFiles('composer.lock')` and add a `restore-keys:` prefix fallback |
| PHPUnit can't reach DB | Use `127.0.0.1` with the mapped port, not the service name (service names only resolve in container jobs) |
| Deploy ran before tests finished | Add the test jobs to `needs:` of the deploy job |
| Two runs per PR push | `push:` + `pull_request:` both trigger — restrict `push:` to `branches: [main]` |