Kubernetes no compatible version found (dotnet)

Question

My Error in Logs Explorer when I deploy my App in Google Cloud>Workloads

It was not possible to find any compatible framework version

The framework 'Microsoft.NETCore.App', version '3.1.0' was not found.

The following frameworks were found: 5.0.4 at [/usr/share/dotnet/shared/Microsoft.NETCore.App]

You can resolve the problem by installing the specified framework and/or SDK.

The specified framework can be found at:

https://aka.ms/dotnet-core-applaunch?framework=Microsoft.NETCore.App&framework_version=3.1.0&arch=x64&rid=debian.10-x64

My Dockerfile:

FROM mcr.microsoft.com/dotnet/sdk

COPY . /app

WORKDIR /app

RUN dotnet publish -c Release -o out

COPY /out .

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

This is the code which is supposed to run

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;


namespace Server
{
    class Program
    {
        private static TcpListener tcpListener;
        public static void Main(string[] args)
        {
            
            tcpListener = new TcpListener(IPAddress.Any, 26950);
   
            tcpListener.Start();
         
            tcpListener.BeginAcceptTcpClient(TCPConnectCallback, null);
            Console.ReadKey();
           
        }
        private static void TCPConnectCallback(IAsyncResult _result)
        {
            TcpClient _client = tcpListener.EndAcceptTcpClient(_result);
            tcpListener.BeginAcceptTcpClient(TCPConnectCallback, null);
        }
    }
}

Solution:

FROM mcr.microsoft.com/dotnet/sdk:3.1 WORKDIR /app

COPY . .

ENTRYPOINT ["dotnet", "run"]

Answer 1

You are using latest image of sdk which in this case is version 5.0.4 . You need to use it 3.1.0 as your application:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1

Try one of these Dockerfile:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster
WORKDIR /app
COPY ./bin/Debug/netcoreapp3.1 .
EXPOSE 80
ENV ASPNETCORE_URLS "http://*:80"
ENTRYPOINT ["dotnet", "Test.dll"]

or

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
WORKDIR /app

# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore

# Copy everything else and build
COPY . ./
RUN dotnet publish -c Release -o out

# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "Test.dll"]```