Blazor Web Assembly App .Net Core托管：发布运行时错误

问题描述

我已经创建了一个简单的Blazor Web Assembly项目，该项目使用.NET 5.0 RC1 Framework托管在.NET Core应用程序中，并且在Visual Studio 2019 Preview的向导过程中添加了授权。它可以在调试中完美运行，但是如果我发布它并尝试连接到服务器，则会收到500错误。检查日志的错误是：

Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HM37MQFV38CV",Request id "0HM37MQFV38CV:00000003": An unhandled exception was thrown by the application.
      System.NullReferenceException: Object reference not set to an instance of an object.
         at Microsoft.Extensions.DependencyInjection.IdentityServerBuilderConfigurationExtensions.<>c.<AddSigningCredentials>b__10_2(IServiceProvider sp)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite,RuntimeResolverContext context)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitCache(ServiceCallSite callSite,RuntimeResolverContext context,ServiceProviderEngineScope serviceProviderEngine,RuntimeResolverLock lockType)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitRootCache(ServiceCallSite singletonCallSite,RuntimeResolverContext context)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite,TArgument argument)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitIEnumerable(IEnumerableCallSite enumerableCallSite,RuntimeResolverContext context)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitNoCache(ServiceCallSite callSite,TArgument argument)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(ServiceCallSite callSite,TArgument argument)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite,RuntimeResolverContext context)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitDisposeCache(ServiceCallSite transientCallSite,TArgument argument)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.Resolve(ServiceCallSite callSite,ServiceProviderEngineScope scope)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType,ServiceProviderEngineScope serviceProviderEngineScope)
         at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
         at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider,Type serviceType)
         at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
         at Microsoft.AspNetCore.Authentication.AuthenticationHttpContextExtensions.AuthenticateAsync(HttpContext context,String scheme)
         at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
         at IdentityServer4.Hosting.BaseUrlMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Builder.Extensions.MapWhenMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware,HttpContext context,Task task)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.HandleException(HttpContext context,ExceptionDispatchInfo edi)
         at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware,Task task)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

我认为该问题与Identity Server和证书有关，但我不知道是什么。

有什么想法吗？

谢谢。

解决方法

使用 .pfx 文件时出现以下错误：

Blazor - app.UseIdentityServer(); with .pfx key file - Unexpected character encountered while parsing number

我终于是这样解决的：

以管理员身份在 Powershell 中创建新证书：

New-SelfSignedCertificate -DnsName "blazortest" -CertStoreLocation "cert:\CurrentUser\My"

appsettings.json：

  "IdentityServer": {
    "Clients": {
      "BlazorTest.Client": {
        "Profile": "IdentityServerSPA"
      }
    },"Key": {
      "Type": "Store","StoreName": "My","StoreLocation": "CurrentUser","Name": "CN=blazortest"
    }
  },

https://docs.microsoft.com/en-us/aspnet/core/security/authentication/identity-api-authorization?view=aspnetcore-3.0#example-deploy-to-azure-app-service

这在本地有效。然后我使用 mmc.exe 将证书导出为 .pfx 文件并通过 Azure App Service -> TLS/SSL settings 上传。

然后我使用 Azure Cloud Shell 启用对证书的访问，如下所示：

az webapp config appsettings set --name <app-name> --resource-group <resource-group-name> --settings WEBSITE_LOAD_CERTIFICATES=<comma-separated-certificate-thumbprints>

https://docs.microsoft.com/en-us/azure/app-service/configure-ssl-certificate-in-code#load-the-certificate-in-code

您也可以通过将 Certificate Thumbprint 添加到 WEBSITE_LOAD_CERTIFICATES 来手动添加 Configuration：

然后它终于奏效了！

如果您从 Azure Cloud Shell 中收到如下错误：

ResourceGroupNotFound：找不到资源组“”。

确保您处于正确的订阅中并使用以下命令设置正确的订阅：

az account show

az account list

az account set --subscription <subscriptionId>

如果您在 IIS 上托管，则需要将 .pfx 证书导入 Personal 的 Local Computer 文件夹，然后选择 Manage Private Keys... 并授予对运行 Application Pool 的用户。

,

好，我已经解决了question/answers

在生产中必须使用证书，因此我创建了一个自签名证书，并将其路径添加到appsettings.json中。