How to create a working Docker Container With .NET 6.0?

I've already managed to create a working container using Node and React.
I'm now trying to create a docker container to operate a simple C# executable which will listen on port 8000 and send back "hello world". It works if I run it locally by visiting http://localhost:8000/
Here is the code:

using System;
using System.Net;
using System.Text;

class Program
{
    static void Main(string[] args)
    {
        string url = "http://localhost:8000/";
        HttpListener listener = new HttpListener();
        listener.Prefixes.Add(url);
        listener.Start();

        Console.WriteLine("Listening on {0}", url);

        while (true)
        {
            HttpListenerContext context = listener.GetContext();
            HttpListenerRequest request = context.Request;
            HttpListenerResponse response = context.Response;

            Console.WriteLine("{0} {1}", request.HttpMethod, request.Url);

            byte[] buffer = Encoding.UTF8.GetBytes("Hello, World!");
            response.ContentLength64 = buffer.Length;
            response.OutputStream.Write(buffer, 0, buffer.Length);
            response.OutputStream.Close();
        }
    }
}

I have the built the program and moved it in a folder in the desktop:

As you can see I've created the Dockerfile, with this content:

FROM mcr.microsoft.com/dotnet/runtime:6.0      

WORKDIR /HelloWorld

COPY . .

EXPOSE 8000

CMD ["/HelloWorld/DockerTest.exe"]

I've then built the image using:

docker build -t imagename:tagname .

And then run the container by using:

docker run --name containername -p 8000:8000 imagename:tagname

The container exits immediately with exit code 1, so a error, and it produces no logs.
What i think I could be doing wrong is using the wrong image for the .NET runtime
(is mcr.microsoft.com/dotnet/runtime:6.0 correct?) or forgetting something else in the Dockerfile. If you have any questions I'll be happy to give you more details

mcr.microsoft.com/dotnet/runtime:6.0 is a Linux container based on Debian 11 - check out info at docker hub:

> 6.0.16-bullseye-slim-amd64, 6.0-bullseye-slim-amd64, 6.0.16-bullseye-slim, 6.0-bullseye-slim, 6.0.16, 6.0 Dockerfile Debian 11 05/03/2023

So it can't run .exe files which are build for Windows.

You need to either switch to Windows container or change command to a valid one for Debian, something like:

ENTRYPOINT ["dotnet", "DockerTest.dll"]

Also you can try using VS tools to add Docker support. This should create a multistage build Docker file which will handle both building and producing the resulting image.

P.S.

• Also I would recommend creating an ASP.NET Core project (using Minimal APIs for simplicity for example) instead of HttpListener directly.

• localhost in "http://localhost:8000/" will mean that it will accept only requests from localhost which in case of dockerized application will be the container itself - see this answer for details and solutions.