c# - 依赖注入(inject)无法解析在 Azure 中运行的 .NET Core Function App 中的类型服务

Question

摘要

我一直遵循 Microsoft 指南 Use dependency injection in .NET Azure Functions将一些依赖注入(inject) (DI) 引入到我们团队正在创建的 Azure 函数中。当我在 Visual Studio 2017 中本地运行并使用 Fiddler 或 Postman 调用该函数时，一切正常 - 我可以调试命中断点，并且通过 DI 设置提供的服务工作正常。然而，当我们将相同的功能部署到 Azure 中时，我们会遇到以下异常:

Unable to resolve service for type 'MyLibrary.ITelemetryClient' while attempting to activate 'MyFunctionApp.GetRemoteSystemsByFeature'.

详细信息

我有一个库程序集 (.NET Standard 2.0)，它公开一个接口(interface) ITelemetryClient 和一个默认实现 ApplicationInsightsTelemetryClient。它们是非常简单的代码 - 我认为这些的实现对于这个问题并不重要，所以我现在会跳过它们。

在定义函数应用程序 (.NET Core 2.2) 的解决方案中，我已确保安装了正确的 NuGet 包:

• Microsoft.Azure.Functions.Extensions v1.0.0
• Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator v1.1.1
• Microsoft.NET.Sdk.Functions v1.0.28

我创建了继承自 FunctionsStartup 的 Startup:

using System;
using System.Runtime.CompilerServices;
using MyLibrary;
using Microsoft.Azure.Functions.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection;

[assembly: FunctionsStartup(typeof(MyFunctionApp.Startup))]
[assembly: InternalsVisibleTo("MyFunctionApp.Tests")]

namespace MyFunctionApp
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddSingleton<MyLibrary.ITelemetryClient, MyLibrary.ApplicationInsightsTelemetryClient>();
        }
    }
}

然后，我为我的函数提供一个请求 MyLibrary.ITelemetryClient 的构造函数:

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Extensions.Logging;
using System;
using System.Threading.Tasks;
using MyLibrary;
using MyRepository;
using MyService;

namespace MyFunctionApp
{
    public class GetRemoteSystemsByFeature
    {
        private readonly MyLibrary.ITelemetryClient _telemetryClient;

        public GetRemoteSystemsByFeature(MyLibrary.ITelemetryClient telemetryClient)
        {
            _telemetryClient = telemetryClient;
        }

        // snip - the rest shouldn't matter for this question
    }
}

所以我认为我做的一切都是正确的。正如我所说，当我在本地调试时，整个事情都有效，并且使用了正确的 ITelemetryClient 实现并成功完成了它的任务。

但是，当它部署到 Azure 时，我们会收到上面引用的错误。该异常的堆栈跟踪没有提及我们的任何代码:

System.InvalidOperationException:
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService (Microsoft.Extensions.DependencyInjection.Abstractions, Version=2.2.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60)
   at lambda_method (Anonymously Hosted DynamicMethods Assembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null)
   at Microsoft.Azure.WebJobs.Host.Executors.DefaultJobActivator.CreateInstance (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\DefaultJobActivator.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 42)
   at Microsoft.Azure.WebJobs.Host.Executors.DefaultJobActivator.CreateInstance (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\DefaultJobActivator.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 32)
   at Microsoft.Azure.WebJobs.Host.Executors.ActivatorInstanceFactory`1+<>c__DisplayClass1_1.<.ctor>b__0 (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\ActivatorInstanceFactory.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 20)
   at Microsoft.Azure.WebJobs.Host.Executors.ActivatorInstanceFactory`1.Create (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\ActivatorInstanceFactory.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 26)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionInvoker`2.CreateInstance (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionInvoker.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 44)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+ParameterHelper.Initialize (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 845)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<TryExecuteAsyncCore>d__16.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.9.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 116)

有什么想法吗？

更新

有人要求我分享 extensions.json 文件的内容:

{
  "extensions":[
    { "name": "Startup", "typeName":"MyFunctionApp.Startup, MyFunctionApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"}
  ]
}

Answer 1

从 MyFunctionApp 卸载 Microsoft.Azure.WebJobs.Script.ExtensionsMetadataGenerator 包并重新部署后，依赖项注入(inject)错误停止，一切开始正常工作。感谢所有提供见解的人，特别是 Katy Shimizu .