GitHub Actions部署Node.js到Azure耗时久，如何优化？

一、实现增量发布（仅部署变更文件） #

完全可以实现增量发布，核心是通过缓存减少重复操作，只处理变更内容：

1. 缓存依赖包
   利用GitHub Actions缓存功能，仅当package-lock.json变更时才重新安装依赖，否则直接复用缓存：

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

2. 识别并打包变更文件

   • 先获取当前提交与上一次部署的差异文件：

     - name: Detect changed files
       id: changed-files
       uses: tj-actions/changed-files@v35
       with:
         separator: "\n"
         files: |
           ./src/**/*
           ./build/**/* # 根据项目结构调整，监控源码和构建产物
     

   • 仅对变更文件执行必要构建（若为编译型源码），再打包这些文件：

     - name: Zip changed files
       if: steps.changed-files.outputs.any_changed == 'true'
       uses: TheDoctor0/zip-release@0.6.1
       with:
         filename: delta-release.zip
         files: ${{ steps.changed-files.outputs.all_changed_files }}
     

   • 部署时上传增量包，关键设置clean: false避免清空现有文件：

     - name: Deploy delta to Staging slot
       if: steps.changed-files.outputs.any_changed == 'true'
       uses: azure/webapps-deploy@v2
       with:
         app-name: 'appname'
         slot-name: 'Staging'
         publish-profile: ${{ secrets.AZUREAPPSERVICE_PUBLISHPROFILE_*** }}
         package: delta-release.zip
         clean: false
     

   注意：如果是编译型项目（如React/Vue），需确保变更源码对应到正确的构建产物，可能需要自定义脚本做文件映射。

二、替代优化方案（无需复杂增量逻辑） #

若增量发布适配成本高，这些方案也能大幅压缩部署时间：

• 切换到Linux运行环境
  当前流程使用windows-latest，Linux环境下npm安装、构建速度普遍更快，将runs-on改为ubuntu-latest，可减少环境初始化和依赖安装耗时。

• 启用Run from Package模式
  在Azure门户进入Web App的「配置」>「常规设置」，开启「运行从包」。该模式下Azure直接从ZIP包运行应用，无需解压，部署速度更快，还能避免文件锁定导致的停机问题。同时仅打包构建后的产物目录（如build），而非整个项目，减少上传文件数量。

• 缓存构建产物
  仅当源码或依赖变更时重新构建，否则复用之前的构建产物：

  - name: Cache build artifacts
    uses: actions/cache@v3
    id: cache-build
    with:
      path: ./build # 替换为你的构建产物目录
      key: ${{ runner.os }}-build-${{ hashFiles('**/src/**', '**/package-lock.json') }}
      restore-keys: |
        ${{ runner.os }}-build-
  
  - name: Install dependencies and build
    if: steps.cache-build.outputs.cache-hit != 'true'
    run: |
      npm install
      npm run build --if-present
  

• 优化部署槽预热
  你已使用Staging槽，需开启槽预热功能，让应用在交换到生产前完成启动，避免用户感知停机。部署完成后再执行槽交换，彻底消除生产环境停机风险。

三、优化后的完整Workflow示例 #

name: Build and deploy Node.js app to Azure Web App

on:
  push:
    branches:
      - develop
  workflow_dispatch:

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Set up Node.js 16.x
        uses: actions/setup-node@v4
        with:
          node-version: '16.x'
          cache: 'npm' # 自动缓存npm依赖

      - name: Cache build artifacts
        id: cache-build
        uses: actions/cache@v3
        with:
          path: ./build
          key: ${{ runner.os }}-build-${{ hashFiles('**/src/**', '**/package-lock.json') }}
          restore-keys: |
            ${{ runner.os }}-build-

      - name: Install dependencies and build
        if: steps.cache-build.outputs.cache-hit != 'true'
        run: |
          npm install
          npm run build --if-present

      - name: Detect changed build files
        id: changed-files
        uses: tj-actions/changed-files@v35
        with:
          separator: "\n"
          files: ./build/**/*

      - name: Zip full release
        if: steps.cache-build.outputs.cache-hit != 'true'
        uses: TheDoctor0/zip-release@0.6.1
        with:
          filename: full-release.zip
          path: ./build

      - name: Zip delta release
        if: steps.cache-build.outputs.cache-hit == 'true' && steps.changed-files.outputs.any_changed == 'true'
        uses: TheDoctor0/zip-release@0.6.1
        with:
          filename: delta-release.zip
          files: ${{ steps.changed-files.outputs.all_changed_files }}

      - name: Upload full artifact
        if: steps.cache-build.outputs.cache-hit != 'true'
        uses: actions/upload-artifact@v3
        with:
          name: node-app-full
          path: full-release.zip

      - name: Upload delta artifact
        if: steps.cache-build.outputs.cache-hit == 'true' && steps.changed-files.outputs.any_changed == 'true'
        uses: actions/upload-artifact@v3
        with:
          name: node-app-delta
          path: delta-release.zip

  deploy:
    runs-on: ubuntu-latest
    needs: build
    environment:
      name: 'Staging'
      url: ${{ steps.deploy-outputs.webapp-url }}

    steps:
      - name: Download full artifact
        if: needs.build.outputs.cache-hit != 'true'
        uses: actions/download-artifact@v3
        with:
          name: node-app-full

      - name: Download delta artifact
        if: needs.build.outputs.cache-hit == 'true'
        uses: actions/download-artifact@v3
        with:
          name: node-app-delta

      - name: Deploy full release to Staging
        if: needs.build.outputs.cache-hit != 'true'
        uses: azure/webapps-deploy@v2
        id: deploy-outputs
        with:
          app-name: 'appname'
          slot-name: 'Staging'
          publish-profile: ${{ secrets.AZUREAPPSERVICE_PUBLISHPROFILE_*** }}
          package: full-release.zip
          clean: true

      - name: Deploy delta release to Staging
        if: needs.build.outputs.cache-hit == 'true'
        uses: azure/webapps-deploy@v2
        id: deploy-delta-outputs
        with:
          app-name: 'appname'
          slot-name: 'Staging'
          publish-profile: ${{ secrets.AZUREAPPSERVICE_PUBLISHPROFILE_*** }}
          package: delta-release.zip
          clean: false

内容的提问来源于stack exchange，提问作者Malky