ASP.NET Core docker build error

Question

I'm new to ASP.NET Core and docker. I've created a simple ASP.NET Core 2.0 app and try to use docker with it on Windows. However, I get this error:

Your Docker server host is configured for 'Linux', however the docker-compose project targets 'Windows'.

Although it seems to be pretty informative error, I can't find where to 'configure host for Windows'

Answer 1

It is docker-compose.dcproj file where you can set up the OS you want to target:

<DockerTargetOS>Linux</DockerTargetOS> 

To switch docker daemon to the same OS you can use Docker tray icon or Docker Settings window (accessible from the same menu):

Answer 2

Well basically the answer of Celestin Bochis and Pavel Agarkov are great. However since .net core 2.2 at least, the os of docker is stored in the .csproj file.

<Project Sdk="Microsoft.NET.Sdk.Web">    <PropertyGroup>     <TargetFramework>netcoreapp2.2</TargetFramework>     <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>     ...    </PropertyGroup>     ... </Project> 

And also don't forget to modify your docker file. The images should be the correct one. For .net core 2.2 That is :

Linux: Microsoft/dotnet:2.2-aspnetcore-runtime AS base microsoft/dotnet:2.2-sdk AS build  Windows: microsoft/dotnet:2.2-aspnetcore-runtime-nanoserver-1803 microsoft/dotnet:2.2-sdk-nanoserver-1803