Authentication 或 Map 中间件启动时出现 Owin InvalidOperation 异常

Question

我们有一个常规的 asp.net Web 应用程序，并添加了基于 Owin 的 OpenID Connect 身份验证 (AzureAD)。在我的 IIS Express 上的本地计算机上，Owin 启动根本没有被触发，即使 Microsoft.Owin.Host.SystemWeb dll 在那里，我们也尝试过设置就像owin:AutomaticAppStartup 和owin:appStartup 一样，没有任何改变。 使 Owin 在本地工作的唯一解决方案是通过调用 Microsoft.Owin.Host.SystemWeb.PreApplicationStart.Initialize();

在 Global.asax.cs WebApplication ctor 中对其进行初始化

当我们在 IIS 上部署到 Azure（云服务，我们可以访问托管 VM）时，应用在 webrole 的 OnStart 期间抛出以下堆栈跟踪：

[InvalidOperationException]: Operation is not valid due to the current state of the object.
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.PushLastObjects(IDictionary`2 environment, TaskCompletionSource`1 completionSource)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContextStage.Epilog(IDictionary`2 env)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.DefaultAppInvoked(IDictionary`2 env)
   at Microsoft.Owin.Mapping.MapMiddleware.<Invoke>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Owin.Security.Infrastructure.AuthenticationMiddleware`1.<Invoke>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContextStage.<RunApp>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Owin.Security.Infrastructure.AuthenticationMiddleware`1.<Invoke>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContextStage.<RunApp>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.<DoFinalWork>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar)
   at System.Web.HttpApplication.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step)
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
-->

有没有人知道什么地方以及什么可能导致问题？我对 Owin 内部结构以及管道的初始化方式没有深入了解，因此我不确定基于此跟踪是在应用程序启动时还是在实际请求期间，但因为它不包含我们实现的任何代码我想它在启动时会失败。也许在常规 IIS 上 Owin 确实正常启动，不像 IIS Express 中那样，而 Global.asax 中的额外调用导致了这个奇怪的异常？

Answer 1

虽然我不确定为什么 Owin 会以如此神秘的方式中断，但事实证明，主要原因确实是明确的 PreApplicationStart.Initialize() 调用，因为在 IIS 上，启动正常运行只需让 SystemWeb ，显然 Owin 请求处理模块的初始化根本不是可重入的。 我们将代码更改为仅在本地环境中进行显式初始化，现在它可以在云中的 IIS 和本地的 IIS Express 上正常工作。