CI/CDでWebアプリを自動デプロイする【GitHub Actions実践】

GitHub ActionsでWebアプリのテスト・ビルド・デプロイを自動化するCI/CDパイプラインを構築します。

CI/CDとは？

GitHub ActionsのワークフローファイルYAML

# .github/workflows/ci-cd.yml
name: CI/CD Pipeline
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - name: Install dependencies
        run: |
          pip install -r requirements.txt
          pip install pytest
      - name: Run tests
        run: pytest

  deploy:
    needs: test  # testジョブ成功後に実行
    if: github.ref == 'refs/heads/main'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          push: true
          tags: ${{ secrets.DOCKER_USERNAME }}/myapp:latest
      - name: Deploy to server
        uses: appleboy/ssh-action@v1.0.0
        with:
          host: ${{ secrets.SERVER_HOST }}
          username: ${{ secrets.SERVER_USER }}
          key: ${{ secrets.SSH_PRIVATE_KEY }}
          script: |
            docker compose pull
            docker compose up -d

まとめ

• GitHub Actionsはpush時に自動でテスト→ビルド→デプロイを実行できる
• needsで前のジョブの成功を条件にできる
• SecretsにAPIキーやSSH鍵を安全に保管する