“The specified framework 'Microsoft.NETCore.App', version '3.1.0' was not found” when create docker image for c# project

Question

I have a c# solution with name Model.sln. It includes around 200 c# projects. I wanna create a docker image and run "dotnet build/public" commands in the image.

step 1: create Dockerfile for this solution.

FROM microsoft/dotnet:3.1.101-aspnetcore-runtime AS base
WORKDIR /Users/Model/bin/Debug/Cli/netcoreapp3.1
ENTRYPOINT ["dotnet", "Model.dll"]

step 2: run $ docker build.

step 3: $docker run -d -t -v /Users/model:/source model

step 4: $ docker exec -it magical_agnesi bash

step 5: #dotnet publish
then I got the following message: Did you mean to run dotnet SDK commands? Please install dotnet SDK from: https://go.microsoft.com/fwlink/?LinkID=798306&clcid=0x409

Don't know why I cannot run dotnet sdk commands in this image. It works in my mac system.

Answer 1

You have to have to have sdk image as runtime image does not have sdk. Please add this image to your docker file.

FROM microsoft/dotnet:2.2-sdk as build

and Please check this one to get full dockerfile example .