GitHub Actions自动化

GitHub Actions是GitHub提供的持续集成/持续部署(CI/CD)服务，它允许你自动化软件开发工作流程，如构建、测试和部署。

GitHub Actions基础

核心概念

1. 工作流(Workflow)：由一个或多个作业组成的自动化过程，由事件触发
2. 事件(Event)：触发工作流的特定活动，如push、pull request或定时任务
3. 作业(Job)：工作流中的一组步骤，在同一运行器上执行
4. 步骤(Step)：可以运行命令或动作的单个任务
5. 动作(Action)：可重用的工作单元，可以是自定义的或来自GitHub Marketplace
6. 运行器(Runner)：执行工作流的服务器，可以是GitHub提供的或自托管的

工作流文件结构

工作流定义在仓库的.github/workflows目录下的YAML文件中：

name: CI/CD Pipeline

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]
  schedule:
    - cron: '0 0 * * *'  # 每天午夜运行

jobs:
  build:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Run tests
        run: npm test

常用触发器

on:
  # 推送到指定分支时触发
  push:
    branches: [ main, develop ]
    paths-ignore: [ 'docs/**', '**.md' ]
    
  # 创建或更新PR时触发
  pull_request:
    types: [ opened, synchronize ]
    
  # 手动触发
  workflow_dispatch:
    inputs:
      environment:
        description: 'Environment to deploy to'
        required: true
        default: 'staging'
        
  # 定时触发
  schedule:
    - cron: '0 0 * * *'  # 每天午夜运行
    
  # 其他工作流完成时触发
  workflow_run:
    workflows: [ "Build" ]
    types: [ completed ]

CI/CD配置与使用

持续集成(CI)配置

以下是一个典型的CI工作流，用于构建和测试代码：

name: Continuous Integration

on:
  push:
    branches: [ main, develop ]
  pull_request:
    branches: [ main ]

jobs:
  test:
    runs-on: ubuntu-latest
    
    strategy:
      matrix:
        node-version: [14.x, 16.x, 18.x]
        
    steps:
      - uses: actions/checkout@v3
      
      - name: Use Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v3
        with:
          node-version: ${{ matrix.node-version }}
          cache: 'npm'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Lint code
        run: npm run lint
        
      - name: Run unit tests
        run: npm test
        
      - name: Run integration tests
        run: npm run test:integration
        
      - name: Upload coverage reports
        uses: codecov/codecov-action@v3
        with:
          token: ${{ secrets.CODECOV_TOKEN }}

持续部署(CD)配置

以下是一个部署到不同环境的CD工作流示例：

name: Continuous Deployment

on:
  push:
    branches: [ main ]
  workflow_dispatch:
    inputs:
      environment:
        description: 'Environment to deploy to'
        required: true
        default: 'staging'
        type: choice
        options:
          - staging
          - production

jobs:
  deploy:
    runs-on: ubuntu-latest
    environment: ${{ github.event.inputs.environment || 'staging' }}
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'
          cache: 'npm'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Build application
        run: npm run build
        
      - name: Deploy to staging
        if: ${{ github.event.inputs.environment == 'staging' || github.event.inputs.environment == null }}
        uses: some-deployment-action@v1
        with:
          target: 'staging'
          token: ${{ secrets.DEPLOY_TOKEN }}
          
      - name: Deploy to production
        if: ${{ github.event.inputs.environment == 'production' }}
        uses: some-deployment-action@v1
        with:
          target: 'production'
          token: ${{ secrets.DEPLOY_TOKEN }}

环境和密钥管理

GitHub Actions提供了安全存储和使用敏感信息的方法：

1. 仓库密钥：

   • 在仓库设置中的"Secrets and variables" > "Actions"中添加
   • 在工作流中使用：${{ secrets.SECRET_NAME }}

2. 环境密钥：

   • 创建环境并添加特定于环境的密钥
   • 在工作流中指定环境：environment: production

3. 变量：

   • 存储非敏感配置信息
   • 可在仓库或环境级别设置
   • 在工作流中使用：${{ vars.VARIABLE_NAME }}

自动化测试与部署

自动化测试策略

1. 矩阵测试：在多个环境或配置上运行测试

jobs:
  test:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, windows-latest, macos-latest]
        node-version: [14.x, 16.x, 18.x]

2. 并行测试：将测试分割为多个作业以加速执行

jobs:
  unit-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm test:unit
      
  integration-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - run: npm test:integration

3. 测试报告：生成和发布测试报告

- name: Run tests
  run: npm test -- --coverage
  
- name: Upload test results
  uses: actions/upload-artifact@v3
  with:
    name: test-results
    path: coverage/

自动化部署方案

1. 部署到GitHub Pages：

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      
      - name: Build
        run: npm run build
        
      - name: Deploy to GitHub Pages
        uses: JamesIves/github-pages-deploy-action@v4
        with:
          folder: build

2. 部署到云服务提供商：

# AWS部署示例
- name: Configure AWS credentials
  uses: aws-actions/configure-aws-credentials@v1
  with:
    aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
    aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
    aws-region: us-east-1
    
- name: Deploy to S3
  run: aws s3 sync ./build s3://my-bucket/
  
- name: Invalidate CloudFront
  run: aws cloudfront create-invalidation --distribution-id ${{ secrets.CF_DISTRIBUTION_ID }} --paths "/*"

3. 使用SSH部署到服务器：

- name: Set up SSH
  uses: webfactory/ssh-agent@v0.7.0
  with:
    ssh-private-key: ${{ secrets.SSH_PRIVATE_KEY }}
    
- name: Deploy to server
  run: |
    scp -r ./build/* user@server:/path/to/deployment
    ssh user@server 'cd /path/to/deployment && ./restart.sh'

常用Actions模板

JavaScript/Node.js项目

name: Node.js CI/CD

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  build-and-test:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Use Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'
          cache: 'npm'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Lint
        run: npm run lint
        
      - name: Test
        run: npm test
        
      - name: Build
        run: npm run build
        
      - name: Upload build artifacts
        uses: actions/upload-artifact@v3
        with:
          name: build
          path: build/

Python项目

name: Python CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: [3.8, 3.9, 3.10]
        
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}
          cache: 'pip'
          
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install flake8 pytest
          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
          
      - name: Lint with flake8
        run: flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
        
      - name: Test with pytest
        run: pytest

Docker项目

name: Docker CI/CD

on:
  push:
    branches: [ main ]
    tags: [ 'v*.*.*' ]
  pull_request:
    branches: [ main ]

jobs:
  build-and-push:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v2
        
      - name: Login to DockerHub
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
          
      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v4
        with:
          images: username/app
          tags: |
            type=semver,pattern={{version}}
            type=ref,event=branch
            type=sha
            
      - name: Build and push
        uses: docker/build-push-action@v4
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

多语言项目

name: Multi-language CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  frontend:
    runs-on: ubuntu-latest
    defaults:
      run:
        working-directory: ./frontend
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '16'
          cache: 'npm'
          cache-dependency-path: './frontend/package-lock.json'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Test frontend
        run: npm test
        
  backend:
    runs-on: ubuntu-latest
    defaults:
      run:
        working-directory: ./backend
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.10'
          cache: 'pip'
          cache-dependency-path: './backend/requirements.txt'
          
      - name: Install dependencies
        run: pip install -r requirements.txt
        
      - name: Test backend
        run: pytest

高级功能与优化

工作流优化技巧

1. 缓存依赖：

- name: Cache Node.js modules
  uses: actions/cache@v3
  with:
    path: ~/.npm
    key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
    restore-keys: |
      ${{ runner.os }}-node-

2. 作业之间共享数据：

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Build
        run: npm run build
      - name: Upload build
        uses: actions/upload-artifact@v3
        with:
          name: build-files
          path: build/
          
  deploy:
    needs: build
    runs-on: ubuntu-latest
    steps:
      - name: Download build
        uses: actions/download-artifact@v3
        with:
          name: build-files
          path: build
      - name: Deploy
        run: ./deploy.sh

3. 条件执行：

steps:
  - name: Deploy to production
    if: github.ref == 'refs/heads/main' && github.event_name == 'push'
    run: ./deploy-prod.sh

自托管运行器

如果需要特定环境或更多资源，可以设置自托管运行器：

1. 添加自托管运行器：

   • 在仓库或组织设置中，点击"Actions" > "Runners" > "New self-hosted runner"
   • 按照指示设置运行器

2. 在工作流中使用：

jobs:
  build:
    runs-on: self-hosted
    steps:
      - uses: actions/checkout@v3
      # 其他步骤...

复用工作流

1. 可重用工作流：创建可在多个仓库中使用的工作流

# .github/workflows/reusable.yml
name: Reusable workflow

on:
  workflow_call:
    inputs:
      environment:
        required: true
        type: string
    secrets:
      deploy-token:
        required: true

jobs:
  deploy:
    runs-on: ubuntu-latest
    environment: ${{ inputs.environment }}
    steps:
      - uses: actions/checkout@v3
      - name: Deploy
        run: ./deploy.sh
        env:
          TOKEN: ${{ secrets.deploy-token }}

2. 调用可重用工作流：

jobs:
  call-workflow:
    uses: ./.github/workflows/reusable.yml
    with:
      environment: production
    secrets:
      deploy-token: ${{ secrets.DEPLOY_TOKEN }}

工作流可视化与监控

1. GitHub Actions仪表板：

   • 在仓库的"Actions"选项卡查看所有工作流运行
   • 检查详细日志和步骤输出

2. 状态徽章：在README中添加工作流状态徽章

![CI/CD](https://github.com/用户名/仓库名/actions/workflows/main.yml/badge.svg)

3. 通知配置：
   • 设置工作流失败时的邮件通知
   • 使用Slack或Teams集成发送通知

- name: Slack notification
  uses: 8398a7/action-slack@v3
  with:
    status: ${{ job.status }}
    fields: repo,message,commit,author,action,eventName,ref,workflow
  env:
    SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
  if: always()