Gitワークフロー戦略完全ガイド：チーム開発を成功に導く実践手法【2025年最新版】

# Git Flow初期化
$ git flow init

# フィーチャー開発開始
$ git flow feature start user-authentication
Switched to a new branch 'feature/user-authentication'

# 開発作業
$ git add .
$ git commit -m "Implement user login functionality"
$ git commit -m "Add validation and error handling"

# フィーチャー完了
$ git flow feature finish user-authentication
Switched to branch 'develop'
Updating 9060376..5d8c8f4
Fast-forward
Deleted branch feature/user-authentication (was 5d8c8f4).

# リリース準備開始
$ git flow release start 1.2.0
Switched to a new branch 'release/1.2.0'

# リリース完了
$ git flow release finish 1.2.0
Switched to branch 'main'
Merge made by the 'ort' strategy.
Tagged '1.2.0'
Switched to branch 'develop'
Deleted branch release/1.2.0 (was da39a3e).

   $ git checkout main
   $ git pull origin main
   $ git checkout -b feature/improve-search-performance

   $ git add src/search.js
   $ git commit -m "Optimize search algorithm with indexing"
   $ git commit -m "Add performance tests for search"

   $ git push origin feature/improve-search-performance
   # GitHubでPRを作成

   $ git checkout main
   $ git merge feature/improve-search-performance
   $ git push origin main
   # 自動デプロイが実行される

   $ git branch -d feature/improve-search-performance
   $ git push origin --delete feature/improve-search-performance

# 機能追加
feature/user-profile-page
feature/payment-integration

# バグ修正
fix/login-validation-error
fix/memory-leak-in-parser

# ドキュメント
docs/api-usage-examples
docs/deployment-guide

# パフォーマンス改善
perf/database-query-optimization
perf/image-compression

# .gitlab-ci.yml の例
stages:
  - test
  - build
  - deploy-staging
  - deploy-production

# テストステージ
test:
  stage: test
  script:
    - npm test
    - npm run lint
  only:
    - main
    - merge_requests

# ステージング環境デプロイ
deploy-staging:
  stage: deploy-staging
  script:
    - docker build -t app:staging .
    - docker push registry/app:staging
    - kubectl apply -f k8s/staging/
  only:
    - pre-production
  environment:
    name: staging
    url: https://staging.example.com

# 本番環境デプロイ
deploy-production:
  stage: deploy-production
  script:
    - docker build -t app:latest .
    - docker push registry/app:latest
    - kubectl apply -f k8s/production/
  only:
    - production
  environment:
    name: production
    url: https://example.com
  when: manual  # 手動承認が必要

# git-flowツールのインストール（macOS）
$ brew install git-flow-avh

# git-flowツールのインストール（Ubuntu）
$ sudo apt-get install git-flow

# プロジェクトの初期化
$ cd your-project
$ git flow init

Which branch should be used for bringing forth production releases?
   - main
Branch name for production releases: [main] 
Branch name for "next release" development: [develop] 

How to name your supporting branch prefixes?
Feature branches? [feature/] 
Bugfix branches? [bugfix/] 
Release branches? [release/] 
Hotfix branches? [hotfix/] 
Support branches? [support/] 
Version tag prefix? []

# 機能開発開始
$ git flow feature start MYFEATURE
Switched to a new branch 'feature/MYFEATURE'

Summary of actions:
- A new branch 'feature/MYFEATURE' was created, based on 'develop'
- You are now on branch 'feature/MYFEATURE'

# 開発作業
$ git add .
$ git commit -m "Implement core functionality"
$ git commit -m "Add unit tests"
$ git commit -m "Update documentation"

# 機能完了（developにマージ）
$ git flow feature finish MYFEATURE
Switched to branch 'develop'
Updating 9060376..5d8c8f4
Fast-forward
 README    |    1 +
 1 file changed, 1 insertion(+)
Deleted branch feature/MYFEATURE (was 5d8c8f4).

// GitHubのブランチ保護設定（REST API）
{
  "required_status_checks": {
    "strict": true,
    "contexts": [
      "continuous-integration/travis-ci",
      "security/snyk"
    ]
  },
  "enforce_admins": true,
  "required_pull_request_reviews": {
    "required_approving_review_count": 2,
    "dismiss_stale_reviews": true,
    "require_code_owner_reviews": true
  },
  "restrictions": null
}

# 作業開始前にmainを更新
$ git checkout main
$ git pull origin main

# 機能ブランチでも定期的にmainをマージ
$ git checkout feature/user-profile
$ git merge main

// 悪い例: 大きなファイル
// user.js (500行)
class User {
  constructor() { /* ... */ }
  authenticate() { /* ... */ }
  updateProfile() { /* ... */ }
  sendNotification() { /* ... */ }
  // ... 多くのメソッド
}

// 良い例: 責任分離
// user/index.js
// user/authentication.js
// user/profile.js
// user/notification.js

# ブランチ命名規則
## フィーチャーブランチ
- `feature/{issue-number}-{short-description}`
- 例: `feature/123-user-authentication`

## バグ修正ブランチ
- `fix/{issue-number}-{short-description}`
- 例: `fix/456-login-validation-error`

## ホットフィックスブランチ
- `hotfix/{version}-{short-description}`
- 例: `hotfix/1.2.1-critical-security-fix`

#!/bin/sh
# .git/hooks/pre-push

protected_branch='main'
current_branch=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

if [ $protected_branch = $current_branch ]; then
    echo "Direct push to main branch is not allowed"
    echo "Please create a pull request"
    exit 1
fi

# ブランチ名のチェック
if [[ ! $current_branch =~ ^(feature|fix|hotfix|experiment)/.+ ]]; then
    echo "Branch name '$current_branch' does not follow naming convention"
    echo "Expected: feature/*, fix/*, hotfix/*, or experiment/*"
    exit 1
fi

# GitHubのAPIを使用した計測例
curl -H "Authorization: token $GITHUB_TOKEN" \
  https://api.github.com/repos/owner/repo/pulls?state=closed | \
  jq '.[] | {
    title: .title,
    created: .created_at,
    merged: .merged_at,
    lead_time_hours: (((.merged_at | fromdateiso8601) - (.created_at | fromdateiso8601)) / 3600)
  }'

-- デプロイ履歴テーブルからの集計例
SELECT 
  DATE_TRUNC('week', deployed_at) as week,
  COUNT(*) as deployments_per_week
FROM deployments 
WHERE deployed_at >= NOW() - INTERVAL '3 months'
GROUP BY week
ORDER BY week;

# 失敗したデプロイの割合
total_deploys=$(git tag --list | wc -l)
failed_deploys=$(git tag --list | xargs -I {} sh -c 'git log {}^..{} --oneline | grep -i "revert\|rollback" | wc -l' | paste -sd+ | bc)
error_rate=$(echo "scale=2; $failed_deploys / $total_deploys * 100" | bc)
echo "Change Error Rate: ${error_rate}%"

# リポジトリ初期化
git init
git add .
git commit -m "Initial commit"
git branch -M main
git remote add origin https://github.com/startup/product.git
git push -u origin main

# team-workflow.md
## 開発フロー

1. mainから機能ブランチを作成
2. 開発 & コミット
3. プルリクエスト作成
4. 1名以上のレビュー
5. mainにマージ & デプロイ

## ブランチ命名
- feature/機能名
- fix/バグ名

# ブランチ構成
main                    # 開発統合
├── staging            # ステージング環境
└── production         # 本番環境

# code-review-guidelines.md
## レビュー基準

### 必須チェック項目
- [ ] テストが含まれている
- [ ] ドキュメントが更新されている
- [ ] パフォーマンスへの影響を考慮している
- [ ] セキュリティ上の問題がない

### レビュー担当
- フロントエンド: @frontend-team
- バックエンド: @backend-team
- DevOps: @devops-team

# 複数プロダクトの管理
main                    # 本番リリース
├── develop            # 次期リリース開発
├── release/v2.1.0     # リリース準備
├── feature/team-a/    # チームA機能群
├── feature/team-b/    # チームB機能群
└── hotfix/v2.0.1      # 緊急修正

# AI支援によるコミットメッセージ生成
$ git add .
$ git commit --ai-message
Suggested commit message: "Implement user authentication with JWT tokens

- Add login endpoint with email/password validation
- Implement JWT token generation and verification
- Add middleware for protected routes
- Include unit tests for authentication logic"

Accept this message? [y/N]:

# .github/workflows/secure-deployment.yml
name: Secure Deployment

on:
  push:
    branches: [main]

jobs:
  security-scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3

      - name: Secret Detection
        uses: trufflesecurity/trufflehog@main
        with:
          path: ./
          base: main
          head: HEAD

      - name: Dependency Vulnerability Scan
        run: |
          npm audit --audit-level critical
          npm run security:check

      - name: SAST Analysis
        uses: github/codeql-action/analyze@v2