如何基于路径过滤器条件执行YAML流水线中的指定任务？

方案1：配置两个独立CI流水线 #

直接创建两个独立的YAML流水线文件，分别对应应用程序和NuGet类库，各自设置专属触发器与路径过滤器，分支变更时仅触发对应路径有变更的流水线。

应用程序流水线（app-pipeline.yml） #

trigger:
  branches:
    include:
      - main
      - develop
  paths:
    include:
      - apps/*
    exclude:
      - nugets/*

stages:
- stage: Build_Deploy_Apps
  jobs:
  - job: Build_And_Deploy
    steps:
    - script: dotnet build ./apps/MyApp/MyApp.csproj --configuration Release
      displayName: '构建应用程序'
    # 添加部署步骤（如Azure App Service部署、容器推送等）

NuGet类库流水线（nuget-pipeline.yml） #

trigger:
  branches:
    include:
      - main
      - develop
  paths:
    include:
      - nugets/*
    exclude:
      - apps/*

stages:
- stage: Pack_Publish_NuGet
  jobs:
  - job: Pack_And_Publish
    steps:
    - script: dotnet pack ./nugets/MyLibrary/MyLibrary.csproj --configuration Release --output $(Build.ArtifactStagingDirectory)
      displayName: '打包NuGet包'
    - task: NuGetCommand@2
      inputs:
        command: 'push'
        packagesToPush: '$(Build.ArtifactStagingDirectory)/**/*.nupkg'
        nuGetFeedType: 'internal'
        publishVstsFeed: '内部包源名称/ID'
      displayName: '发布至内部NuGet源'

方案2：通过路径变更设置变量，条件触发对应任务 #

在单个流水线中先检测路径变更，输出变量标记是否需要构建应用或NuGet，后续阶段/作业根据变量值决定是否执行。

trigger:
  branches:
    include:
      - main
      - develop
  paths:
    include:
      - apps/*
      - nugets/*

variables:
  - name: shouldBuildApps
    value: 'false'
  - name: shouldBuildNugets
    value: 'false'

stages:
- stage: Detect_Changes
  jobs:
  - job: Check_Path_Changes
    outputs:
      buildApps: $[steps.set_output_vars.outputs.buildApps]
      buildNugets: $[steps.set_output_vars.outputs.buildNugets]
    steps:
    - bash: |
        # 获取本次提交变更的文件列表
        CHANGED_FILES=$(git diff --name-only HEAD~1 HEAD)
        # 判断是否有apps文件夹下的变更
        if echo "$CHANGED_FILES" | grep -q "^apps/"; then
          echo "##vso[task.setvariable variable=buildApps;isOutput=true]true"
        fi
        # 判断是否有nugets文件夹下的变更
        if echo "$CHANGED_FILES" | grep -q "^nugets/"; then
          echo "##vso[task.setvariable variable=buildNugets;isOutput=true]true"
        fi
      displayName: '检测路径变更'
      name: set_output_vars
      # 若使用Windows代理，替换为PowerShell脚本
      # pwsh: |
      #   $changedFiles = git diff --name-only HEAD~1 HEAD
      #   if ($changedFiles -match "^apps/") {
      #     Write-Host "##vso[task.setvariable variable=buildApps;isOutput=true]true"
      #   }
      #   if ($changedFiles -match "^nugets/") {
      #     Write-Host "##vso[task.setvariable variable=buildNugets;isOutput=true]true"
      #   }

- stage: Build_Apps
  condition: eq(dependencies.Detect_Changes.outputs['Check_Path_Changes.buildApps'], 'true')
  jobs:
  - job: Build_Deploy_App
    steps:
    - script: dotnet build ./apps/MyApp/MyApp.csproj --configuration Release
      displayName: '构建应用'
    # 添加部署步骤

- stage: Build_Nugets
  condition: eq(dependencies.Detect_Changes.outputs['Check_Path_Changes.buildNugets'], 'true')
  jobs:
  - job: Pack_Publish_NuGet
    steps:
    - script: dotnet pack ./nugets/MyLibrary/MyLibrary.csproj --configuration Release --output $(Build.ArtifactStagingDirectory)
      displayName: '打包NuGet包'
    - task: NuGetCommand@2
      inputs:
        command: 'push'
        packagesToPush: '$(Build.ArtifactStagingDirectory)/**/*.nupkg'
        nuGetFeedType: 'internal'
        publishVstsFeed: '内部包源名称/ID'
      displayName: '发布NuGet包'

方案3：始终触发流水线，按需执行任务 #

流水线始终触发，但每个阶段/作业仅在对应路径有变更时执行；若应用依赖NuGet包，可设置阶段依赖关系，确保NuGet构建完成后再执行应用构建。

trigger:
  branches:
    include:
      - main
      - develop
  paths:
    include:
      - apps/*
      - nugets/*

stages:
- stage: Build_Nugets
  condition: |
    $[
      git diff --name-only HEAD~1 HEAD | grep -q "^nugets/"
    ]
  jobs:
  - job: Pack_Publish_NuGet
    steps:
    - script: dotnet pack ./nugets/MyLibrary/MyLibrary.csproj --configuration Release --output $(Build.ArtifactStagingDirectory)
      displayName: '打包NuGet包'
    - task: NuGetCommand@2
      inputs:
        command: 'push'
        packagesToPush: '$(Build.ArtifactStagingDirectory)/**/*.nupkg'
        nuGetFeedType: 'internal'
        publishVstsFeed: '内部包源名称/ID'
      displayName: '发布NuGet包'

- stage: Build_Apps
  # 若应用依赖NuGet包，设置依赖关系；否则可去掉dependsOn
  dependsOn: Build_Nugets
  condition: |
    $[
      or(
        git diff --name-only HEAD~1 HEAD | grep -q "^apps/",
        git diff --name-only HEAD~1 HEAD | grep -q "^nugets/"
      )
    ]
  jobs:
  - job: Build_Deploy_App
    steps:
    - script: dotnet build ./apps/MyApp/MyApp.csproj --configuration Release
      displayName: '构建应用'
    # 添加部署步骤

注意：若使用Windows代理，需将bash脚本替换为PowerShell版本，逻辑一致。

内容的提问来源于stack exchange，提问作者bubbleking