C3D.Extensions.SystemWeb.OpenTelemetry.Application 0.1.17-g0d0663aa8c

AppHost Packages

C3D.Extensions.Aspire.IISExpress

A way to reference and execute an IIS Express based project (ASP.NET 4.x) using Aspire. Connects to the instance of VisualStudio running the AprireHost and attaches the debugger to the IIS Express instance so that the project can be debugged as normal. Adds a healthcheck to the IIS Express resource to show whether the debugger has been attached. A future option would be to send the initial request to spin up the site once the debugger is attached.

C3D.Extensions.Aspire.VisualStudioDebug

A way to get VisualStudio to attach the debugger for the AspireHost to a running executable project (such as an IISExpressProjectResource). Uses a BackgroundService to montior for the Process Id (via executable.pid) and C3D.Extensions.VisualStudioDebug to manipulate VisualStudio. Appropriate debug engines can be enabled, such as Managed (.NET Framework 4.x) to allow debugging of IIS Express based ASP.Net 4.x Projects. This mechanism could be extended to attach the debugger to apps in docker containers, or other languages such as nodejs.

C3D.Extensions.VisualStudioDebug

Encapsulates accessing Visual Studio using the IRunningObjectTable COM mechanism and makes it easy to connect and use the debug interface from the DTE. Provides constants for WellKnown Engines and Transports. Based in part on on code from this gist.

Client Packages

C3D.Extensions.SystemWeb.OpenTelemetry.Application

An HttpApplication derived object that configures OTLP etc. automatically. Application_Start method is virtual and can be overridden. OTLP exporter will automatically start and stop with the application. You can customize each type of telemetry, by adding to or completely overriding each of

• ConfigureLogging
• ConfigureMetrics
• ConfigureTracing

The following methods are also provided for ease of use

• CreateServiceCollection - Initialize the ServiceCollection
• ConfigureServiceProvider - This could be used to register your own objects in a DI container, or adjust things like logging.
• UseServiceProvider - This is called after the service provider is built, but before OTLP is started.

Samples

Simple

A basic project based on MSBuild.SDK.SystemWeb which shows a very basic MVC5 application using the new SDK style, and can be launched by Aspire. It supports OpenTelemetry and will correctly connect to the Aspire Dashboard. Note that being IIS (Express) based, it does not start until the first web request, so you will need to launch it using the link on the dashboard.

EF6

A more advanced project which uses Microsoft.Data.SqlClient to allow connections to any SQL Server using the latest technologies. This has some code to allow connection strings to be copied from web.config to a Microsoft.Extensions.Configuration based version, and creates a DependencyInjection container based on Microsoft.Extensions.DependencyInjection. There are custom implementations of IServiceProvider for WebObjectActivator and IDependencyResolver for MVC5. These allow you to inject ILogger and DbContext to a controller, filter etc. This is a nieve implementation that does not deal with request scopes - all objects are either Singleton or Transient. A localdb is created in the App_Data folder if you run the application directly and each time a new blog is created on startup. If launched via aspire, it will wait for the sql server to start then start IISExpress. The database will be created afresh each time and there will only be a single blog entry.

SWA

This shows using Aspire to handle Incremental ASP.NET to ASP.NET Core Migration. This consists of a Full Framework example app using MVC, with some of the code from the RemoteSession example added in. The Core app is lightweight and only contains YARP, a Session variable route (per the RemoteSession example), OTLP telemetry, and HeathChecks. Apire sets up a randomized app key used by both applications, and wires up the Urls for YARP etc. Traces show the request span of the core app, the proxy request, and the framework processing.

Debugging

Because Aspire doesn't natively know how to attach the debugger to IIS Express, when adding an IISExpressProject, the VisualStudioDebug mechanism will be enabled by default with DebugMode.VisualStudio.

This can be overridden with one of

	.WithDebugger()
	.WithDebugger(DebugMode.None)
	.WithDebugger(DebugMode.Environment)
	.WithDebugger(DebugMode.VisualStudio)

• The default is VisualStudio
• None means do not attach the debugger.
• Environment sets the environment variable Launch_Debugger_On_Start to true. This is checked for by a PreApplicationStartMethod which will attempt to launch a debugger.
• VisualStudio uses a hook and COM to get the running IDE and attach the debugger to IIS Express after it starts.

Known Issues

• The $(SolutionDir)\.vs\$(SolutionName)\config\applicationhost.config file is not checked in as part of the source so you will probably have to manually select each web application and run it once manually to setup the appropriate information.
• There is no 'easy' way to automatically start up the IIS Express based website (it might be possible to do via a healthcheck poll or similar but that is out of scope at this time.)

Extension Points

The C3D.Extensions.Aspire.VisualStudioDebug package has eventing enabled that fires BeforeDebugEvent and AfterDebugEvent. This could be listened for, and used to make an http call to any IIS Express based application to start them up after the debugger has attached.