Will this work in dot net 6 in a docker container?

[RobotX5]

Will this work in dot net 6 in a docker container?
Do you have any patterns/examples now that startup.cs is removed?

based on my testing it seems to be failing on string text = new StreamReader(Request.Body).ReadToEnd(); call.
I don't currently have access to the docker logs in prd so I am not exactly sure what is failing.

Thanks

[CarloP95]

I'm trying to create an Alexa skill for my studies and i can say that it seems not to work seamlessly.

I have the same setup you are talking about: .Net 6 and the skill will be deployed in a docker container.

The problem is in this piece of code:

private static async Task<string> GetBodyFromRequestAsync(HttpRequest httpRequest)
{
            httpRequest.Body.Position = 0;
            var body = await httpRequest.ReadAsStringAsync();
            httpRequest.Body.Position = 0;

            return body;
}

Since it sets the position of the body it gives System.NotSupportedException with the following error
An unhandled exception has occurred while executing the request. System.NotSupportedException: Specified method is not supported. at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpRequestStream.set_Position(Int64 value) at Alexa.NET.Security.Functions.AlexaRequestValidationFunctionsExtension.GetBodyFromRequestAsync(HttpRequest httpRequest).

Then, if you try to fix with Request.EnableBuffering() as someone suggests on various issues of Asp.NET core, the ReadAsStringAsync starts to complain about not finding a type into an assembly as follows.

System.TypeLoadException: Could not load type 'Microsoft.AspNetCore.Http.Internal.BufferingHelper' from assembly 'Microsoft.AspNetCore.Http, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. at Microsoft.Azure.WebJobs.Extensions.Http.HttpRequestExtensions.ReadAsStringAsync(HttpRequest request)

I'm working on a solution, but any suggestion will be appreciated,
Regards

[CarloP95]

I found the solution.

If you want to use the SkillRequest.ValidateRequestAsync extension method it is necessary to configure your .Net 6 Program.cs with the following middleware. It must be done before any app.Use but not before Swagger middleware if you're using it

app.Use((context, _next) =>
{
    context.Request.EnableBuffering();
    return _next(context);
});

If you want to use the middleware with the app.UseAlexaRequestValidation you must change the Invoke method in the following way

            // CHANGES: no more context.Request.EnableRewind()
            context.Request.EnableBuffering();
            
            // Verify SignatureCertChainUrl is present
            context.Request.Headers.TryGetValue("SignatureCertChainUrl", out var signatureChainUrl);
            if (String.IsNullOrWhiteSpace(signatureChainUrl))
            {
                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }

            Uri certUrl;
            try
            {
                certUrl = new Uri(signatureChainUrl);
            }
            catch
            {
                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }

            // Verify SignatureCertChainUrl is Signature
            context.Request.Headers.TryGetValue("Signature", out var signature);
            if (String.IsNullOrWhiteSpace(signature))
            {
                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }
            // CHANGES: read the body async
            string body = await new StreamReader(context.Request.Body).ReadToEndAsync();
            context.Request.Body.Position = 0;

            if (String.IsNullOrWhiteSpace(body))
            {
                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }
            var valid = await RequestVerification.Verify(signature, certUrl, body);
            if (!valid)
            {
                context.Response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }

            await _next(context);

Just a final tip:

If your using this netstandard2.0 project in your .Net 6 application, you can encounter some problems with Assembly info. I fixed them by adding the following lines to your .csproj

    <PropertyGroup>
        <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
    </PropertyGroup>

If you want, i made a fork for using this library in an application.
Regards

[RobotX5]

this looks like it will help although i am having an issue adding the project to my solution. did you upgrade the solution to dot net 6 if so can you please check that in to your branch. I can not get your branch to work.

[CarloP95]

You're right.. I've integrated the library with git submodules.

There should be no problems using a netstandard library with .NET 6 except the one i described above.
I'll do a sample and upload it as soon as i can

[CarloP95]

I've just seen what i've done.

Since i've done a git clone into the directory of my Alexa Skill, Visual Studio saw that code as if it was part of my project and not a netstandard 2.0 library.

As a workaround you can do the same thing. In my spare time i'll investigate if it works as a standalone library

[CarloP95]

I've done some experiments upgrading the library in netstandard2.1 to use C#8.0 (you can find everything in the netstandard2.1 branch); i've fixed dependency problems and then i attached the two libraries (middleware and functions) as projects to my Alexa Skill Solution.

Then i started debugging everything but i keep getting this error.

System.MissingMethodException: Method not found: 'System.Threading.Tasks.Task`1<Boolean> Alexa.NET.Request.RequestVerification.Verify(System.String, System.Uri, System.String)'.
   at Alexa.NET.Security.Middleware.AlexaRequestValidationMiddleware.Invoke(HttpContext context)
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[TStateMachine](TStateMachine& stateMachine)
   at Alexa.NET.Security.Middleware.AlexaRequestValidationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext context)
   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

Since i've already got Alexa.Net in the dependencies of all project i assume that is a runtime problem of netstandard2.1 and .net6.0; maybe some runtime error since in the MS documentation is written that

The only reason to retarget from .NET Standard to .NET 5+ would be to gain access to more runtime features, language features, or APIs