Hosting Startup is not working in dotnet core 3.0 Azure App Service (System.MissingMethodException: Method not found)

[valeriob]

Hi,
i'm using the Microsoft.ApplicationInsights.Profiler.AspNetCore 2.0.0-beta1 in azure App Service with configured runtime netcore 3.0 and the following environment variable
ASPNETCORE_HOSTINGSTARTUPASSEMBLIES=Microsoft.ApplicationInsights.Profiler.AspNetCore
It fails with this exception :

2019-10-25T15:09:06.749908649Z Unhandled exception. System.MissingMethodException: Method not found: 'Microsoft.AspNetCore.Hosting.IHostingEnvironment Microsoft.AspNetCore.Hosting.WebHostBuilderContext.get_HostingEnvironment()'.
2019-10-25T15:09:06.749966649Z at Microsoft.AspNetCore.Hosting.ServiceProfilerInjection.<>c.b__0_0(WebHostBuilderContext hostingContext, IConfigurationBuilder config)
2019-10-25T15:09:06.749973349Z at Microsoft.AspNetCore.Hosting.WebHostBuilder.BuildCommonServices(AggregateException& hostingStartupErrors)
2019-10-25T15:09:06.749978149Z at Microsoft.AspNetCore.Hosting.WebHostBuilder.Build()
2019-10-25T15:09:06.756355094Z at MyApp.Program.Main(String[] args) in C:\BuildAgent\work\bfbade9ea212e645\MyApp\Program.cs:line 14

Everything works fine if i disable it (by removing the env variable above).
Thanks

[xiaomi7732]

@valeriob, Thanks for your report. Hosting startup is not supported in 2.0.0-beta1. Please follow the example of Quick Start to enable Profiler.

Also, could you please tell us what is the reason for you to choose to use hosting startup? It will help us decide what's the next priority.

Thanks!

[valeriob]

I like it because it's automatically enabled via env variable on production environment, so it will not run during development, and it's non invasive, can be enabled/disabled in prod without code deploy.

[xiaomi7732]

Thanks @valeriob for your feedback. Just in case you don't know, this environment variable can be used as a kill switch of the profiler:

ServiceProfiler__IsDisabled

Check out the documentation: Configuration References.

[valeriob]

I'm trying 2.0.0-beta2, but it does not work with dotnet core 3.0, i get this error during startup :

System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Diagnostics.PerformanceCounter, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.'

[xiaomi7732]

@valeriob That is interesting. Let's troubleshoot.
I assume the application failed to start at all, right? Are you running it on Windows or Linux? Could you please run dotnet --info and past the output here?

[valeriob]

Hi,
i created a brand new aspnet core 3.0 application, added the nuget package, those 2 lines in configure services
services.AddApplicationInsightsTelemetry(); // Enable Application Insights telemetry
services.AddServiceProfiler(); // Add this line of code to Enable Profiler
and this code in the appsettings.json:
"ApplicationInsights": {
"InstrumentationKey": "replace-with-your-instrumentation-key"
}
i get this that exception.

dotnet --info :
.NET Core SDK (reflecting any global.json):
Version: 3.0.100
Commit: 04339c3a26

Runtime Environment:
OS Name: Windows
OS Version: 10.0.18362
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\3.0.100\

Host (useful for support):
Version: 3.0.0
Commit: 7d57652f33

.NET Core SDKs installed:
2.1.802 [C:\Program Files\dotnet\sdk]
2.2.103 [C:\Program Files\dotnet\sdk]
3.0.100 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.0.0 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

[xiaomi7732]

@valeriob, so, you are running it locally on your box, right? I ran it in the same environment and didn't have a problem. If possible, could you please run your app as administrator and give it another shoot? Let's see if that is due to permission issue before we try the fancy fuslogvw.

[valeriob]

Yes, i never run as admin.
But i can reproduce it on many machines, in vs F5 both admin and normal user.

[xiaomi7732]

By 'vs', I think you mean Visual Studio? Could you please share the version number for VS?

To sort out visual studio magics, in the project folder, run:

dotnet run

Does it work?

Also, could you please paste your project file(*.csproj), just want to see project references and that may help us repro the issue here.

[valeriob]

Yes, visual studio 16.3.6, and it does not work with dot net run eather.

[xiaomi7732]

@valeriob I tried the same steps in VS 16.3.6 and it worked for me. There must be something I missed. Let me share my project and you can compare it with yours. At the same time, if you will to, share the project with me and I can take a look at it for you as well.

WebApplication.zip

[valeriob]

Hi xiaomi,
i saw that you added the guide for .netcore 3 exactly after i opened the issue. i diagnosed the problem, and it's due to the dependency required for Microsoft.ApplicationInsights.AspNetCore must be at least 2.8+, while the nuget package requires only Microsoft.ApplicationInsights.AspNetCore (>= 2.3.0).

I suggest to upgrade the nuget package to reflect the real version dependency.
Thanks
Valerio

[xiaomi7732]

@valeriob Oh~ that is why. That makes sense. I'll look into how to get that fixed.

[xiaomi7732]

Hey @valeriob, just FYI, the hosting startup for .NET Core 3.x is coming soon in version 2.1.0-*.

[valeriob]

Thanks! i'll keep an eye on that !