---
id: wiki-20260508-continuous-integration-ci--redir
title: Continuous Integration (CI)
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [CI, Continuous Integration, 지속적 통합]
duplicate_of: none
source_trust_level: A
confidence_score: 0.92
verification_status: applied
tags: [cicd, devops, automation, testing]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: yaml
  framework: GitHub Actions, GitLab CI, Jenkins
---

# Continuous Integration (CI)

## 매 한 줄
> **"매 every commit 의 main branch 의 automated build + test"**. 매 Grady Booch (1991) 의 coin → Martin Fowler (2000) 의 popularize → 매 2026 의 trunk-based dev + GitHub Actions 의 dominant practice. 매 integration hell 의 prevent — 매 small frequent merge + fast feedback (<10 min).

## 매 핵심

### 매 Practices
- **Single source repo** (trunk-based, optionally short-lived feature branches).
- **Automated build** on every push.
- **Self-testing build** (unit + integration).
- **Daily commit** to main (최소).
- **Build fast** (<10 min target).
- **Test in clone of prod** (Docker, ephemeral env).
- **Visible status** (badge, Slack notify).
- **Fix red main immediately** (revert > forward fix).

### 매 CI vs CD
- **CI**: build + test on every push — main 의 always green.
- **CD (Delivery)**: 매 always-shippable artifact + manual prod gate.
- **CD (Deployment)**: 매 fully automated to prod.

### 매 응용
1. Pre-merge: PR check (lint, test, type, build).
2. Post-merge: artifact build + push.
3. Nightly: e2e, perf, security scan.
4. Release: tag → publish (npm, container).

## 💻 패턴

### GitHub Actions PR check
```yaml
name: pr
on: { pull_request: { branches: [main] } }
jobs:
  ci:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v3
      - uses: actions/setup-node@v4
        with: { node-version: 20, cache: pnpm }
      - run: pnpm install --frozen-lockfile
      - run: pnpm lint
      - run: pnpm typecheck
      - run: pnpm test --coverage
      - run: pnpm build
      - uses: codecov/codecov-action@v4
```

### Branch protection (main)
```yaml
# .github/branch-protection.yml (or via API)
required_status_checks:
  strict: true
  contexts: [ci/lint, ci/test, ci/build]
required_pull_request_reviews: { required_approving_review_count: 1 }
enforce_admins: true
```

### Parallel matrix
```yaml
jobs:
  test:
    strategy:
      fail-fast: false
      matrix:
        node: [18, 20, 22]
        os: [ubuntu-latest, macos-latest, windows-latest]
    runs-on: ${{ matrix.os }}
```

### Cache
```yaml
- uses: actions/cache@v4
  with:
    path: ~/.pnpm-store
    key: pnpm-${{ runner.os }}-${{ hashFiles('pnpm-lock.yaml') }}
```

### Pre-commit (Husky + lint-staged)
```json
{ "lint-staged": { "*.{ts,tsx}": ["eslint --fix", "prettier --write"] } }
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| GitHub repo | GitHub Actions |
| GitLab self-host | GitLab CI |
| Java enterprise | Jenkins (with Jenkinsfile) |
| Monorepo, perf-critical | Nx Cloud / Turborepo Remote Cache |
| OSS multi-platform | GitHub Actions + matrix |

**기본값**: 매 GitHub Actions + branch protection + required check.

## 🔗 Graph
- 부모: [[CI/CD Pipeline]] · [[DevOps]]
- 변형: [[Continuous Delivery]] · [[Continuous Deployment]]
- 응용: [[Trunk-Based Development]] · [[Pull Request Workflow]]
- Adjacent: [[TeamCity]] · [[Jenkins]] · [[GitOps]] · [[Pre-commit Hook]]

## 🤖 LLM 활용
**언제**: 매 workflow YAML 의 generation, action 의 lookup, matrix 의 expansion.
**언제 X**: 매 secret handling — 매 OIDC + GitHub Secrets manual review.

## ❌ 안티패턴
- **Long-lived feature branch**: 매 merge hell — 매 short-lived (<3 day).
- **Skipping tests** (`[skip ci]` 의 abuse): 매 main 의 break.
- **Slow CI** (>15 min): 매 PR backlog — 매 cache + parallelize.
- **Flaky tests** 의 retry abuse: 매 fix 의 root cause.
- **Manual deploy from laptop**: 매 reproducibility 의 zero — 매 CI 의 only.

## 🧪 검증 / 중복
- Verified (Fowler "Continuous Integration", GitHub Actions docs).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — practices + Actions/branch protection patterns |