Azure DevOps中Testcontainers for .NET无法检测Docker端点问题求助

团队调研Testcontainers for .NET库时，其演示项目在本地IDE及CLI环境下运行测试均正常，但在Azure DevOps流水线执行时出现如下错误：

System.AggregateException : One or more errors occurred. (Cannot detect the Docker endpoint. Use either the environment variables or the ~/.testcontainers.properties file to customize your configuration:
    https://dotnet.testcontainers.org/custom_configuration/ (Parameter 'DockerEndpointAuthConfig')) (The following constructor parameters did not have matching fixture data: SqlServerWebApplicationFactory factory)
    ---- System.ArgumentException : Cannot detect the Docker endpoint. Use either the environment variables or the ~/.testcontainers.properties file to customize your configuration:
    https://dotnet.testcontainers.org/custom_configuration/ (Parameter 'DockerEndpointAuthConfig')
    ---- The following constructor parameters did not have matching fixture data: SqlServerWebApplicationFactory factory

对应的Azure DevOps流水线配置如下：

trigger:
- master

variables:
  buildConfiguration: 'Release'

jobs:
  - job: BuildAndTest
    displayName: "Solution Build and Test"
    pool:
      name: 'Default'

    steps:
    - task: UseDotNet@2
      displayName: 'Use .NET SDK 7.x'
      inputs:
        packageType: sdk
        version: '7.0.x'
    
    - script: dotnet build --configuration $(buildConfiguration)
      displayName: 'dotnet build $(buildConfiguration)'
    
    - task: DotNetCoreCLI@2
      displayName: 'Execute Tests'
      inputs:
        command: test
        projects: '**/*Tests/*.csproj'
        arguments: '--configuration $(buildConfiguration)'

请问流水线YAML文件或集成测试配置中是否存在遗漏？已知有类似问题案例，但本项目未在Docker构建或Docker-in-Docker场景下运行测试，场景有所不同。

1. 代理池缺少Docker环境 #

Testcontainers核心依赖Docker启动测试所需的容器化服务（比如演示项目中的SQL Server），无论是否使用Docker-in-Docker模式，执行测试的Azure DevOps代理机器必须已安装并运行Docker服务。你的流水线指定了pool: name: 'Default'，需确认该代理池的机器是否满足要求：

• Linux代理：Docker服务已启动，当前用户拥有Docker操作权限
• Windows代理：Docker Desktop已安装并运行，启用对应容器模式

2. 未显式配置Docker端点环境变量 #

如果代理机器的Docker端点不是默认路径，Testcontainers无法自动检测到，需在流水线测试任务中显式配置环境变量：

- task: DotNetCoreCLI@2
  displayName: 'Execute Tests'
  inputs:
    command: test
    projects: '**/*Tests/*.csproj'
    arguments: '--configuration $(buildConfiguration)'
  env:
    # Windows代理使用该端点
    DOCKER_HOST: "npipe:////./pipe/docker_engine"
    # Linux代理替换为：unix:///var/run/docker.sock

3. 测试夹具的连锁依赖问题 #

错误中提到的SqlServerWebApplicationFactory夹具初始化失败，是Docker端点检测失败的连锁反应——Testcontainers无法启动依赖的SQL Server容器，导致夹具无法完成初始化，进而无法为测试类提供实例。解决Docker相关问题后，该错误会自动消失。

内容的提问来源于stack exchange，提问作者Pete