什么是 CI/CD，它为什么很重要？

Question

什么是 CI/CD，它为什么很重要？

Accepted Answer

**CI/CD** 代表 **Continuous Integration**（持续集成）和 **Continuous Delivery/Deployment**（持续交付/部署）— 这些实践可以**自动化**软件的构建、测试和部署。目标是频繁、可靠和快速地发布变更，用自动化取代手动的、容易出错的流程。

## CI — Continuous Integration

```text
CONTINUOUS INTEGRATION: developers frequently merge code into a shared branch, and each
change is AUTOMATICALLY built and tested:
  → on every push/PR: build the code + run tests (automatically)
  → catch integration problems and bugs EARLY (immediately, not weeks later)
  → keep the main branch in a working state
→ Frequent integration + automated verification = fewer, smaller, easier-to-fix problems.
```

## CD — Continuous Delivery / Deployment

```text
CONTINUOUS DELIVERY → code is always in a DEPLOYABLE state; deployment is automated
  but triggered MANUALLY (one click to release)
CONTINUOUS DEPLOYMENT → every change that passes the pipeline is AUTOMATICALLY deployed
  to production (no manual step) — fully automated releases
→ Both automate the release process for fast, reliable deployments.
```

## CI/CD 流程

```text
Code push → BUILD → TEST → (deploy to staging) → (deploy to production)
  → an automated PIPELINE runs these steps on every change
  → if any step fails, the pipeline stops (broken code doesn't proceed)
```

## CI/CD 为什么重要

```text
✓ FASTER releases — automate the slow, manual build/test/deploy process
✓ FEWER bugs reach production — automated testing catches issues early
✓ RELIABLE, consistent deployments — same automated process every time (no human error)
✓ FAST FEEDBACK — developers know quickly if a change broke something
✓ Enables frequent, small releases (lower risk than big infrequent ones)
```

## 为什么这很重要

理解 CI/CD 是必不可少的、广泛适用的知识，因为它是现代软件开发中的一项基础实践，被几乎所有专业团队用于高效、可靠地交付软件。**Continuous Integration**（在开发人员频繁合并代码时自动构建和测试每项变更）解决了一个真实的问题 — 没有它，集成问题和 bug 会累积并在后期才显现（痛苦的、难以修复的"集成地狱"），而 CI **及早发现问题**（在每次变更时立即发现）并保持主分支工作状态，使开发更顺畅、更可靠。**Continuous Delivery/Deployment**（自动化发布流程，使代码始终可部署，通过一次点击或自动发布）使部署**快速、可靠和一致** — 用自动化取代了缓慢、容易出错的手动部署。

理解 **CI/CD 流程**（在每次变更时运行的自动化序列 build → test → deploy，如果任何步骤失败则停止，使得损坏的代码不会进行下去）是核心概念。

理解 **CI/CD 为什么很重要** — 更快的发布、更少的 bug 到达生产环境（自动化测试）、可靠一致的部署（无人为错误）、快速反馈，以及支持频繁的小版本发布（这比大规模不频繁的发布风险更低）— 解释了为什么它对软件交付具有变革意义，并被普遍采用。

CI/CD 是现代 DevOps 的中心，也是专业团队如何交付软件的方式。

由于 CI/CD 是专业软件开发中的基础、几乎通用的实践（为了速度、可靠性和质量而自动化构建、测试和部署），并且由于理解它是什么、流程概念和它的好处是现代软件工作的基础，理解 CI/CD 是必不可少的、广泛适用的知识 — 是支撑当代软件如何构建和交付的核心实践，是开发人员的预期知识，也是可靠、高效的软件交付的基础。