Docker on Windows does not support COPY --from? - docker

I am trying to make use of this Docker construct:
Optionally a name can be given to a new build stage by adding AS name
to the FROM instruction. The name can be used in subsequent FROM and
COPY --from= instructions to refer to the image built in
this stage.
But I get this message:
COPY failed: stat /var/lib/docker/tmp/docker-builder869050639/-–from=build-env:
no such file or directory
Is copying files from a previous stage supported on Docker for Windows 17.09.0-ce-win33 (13620)? This is the Dockerfile:
FROM microsoft/dotnet:2.0-sdk AS build-env
WORKDIR /app
COPY ./ ./
RUN dotnet build ProviderApi.csproj
RUN dotnet publish ProviderApi.csproj -c Release -r linux-x64 -o out
FROM microsoft/dotnet:2.0-runtime-deps
WORKDIR /app
COPY -–from=build-env /app/out/ ./
EXPOSE 80
ENTRYPOINT ["./ProviderApi"]

The problem was that the destination directory was not present in the docker image of the final build stage. Here is the working Dockerfile for future reference.
FROM microsoft/aspnetcore-build:2.0.3-stretch AS build-env
WORKDIR /app
COPY . ./
RUN dotnet build ProviderApi.csproj
RUN dotnet publish ProviderApi.csproj -c Release -r linux-x64 -o out
FROM microsoft/aspnetcore:2.0.3-stretch
RUN mkdir /app
COPY --from=build-env /app/out /app
ENV ASPNETCORE_URLS=http://+:5001
EXPOSE 5001
ENTRYPOINT ["/app/ProviderApi"]

have you tried with lowercase "as"? (seems like a long-shot, I see examples of both around)
FROM microsoft/dotnet:2.0-sdk as build-env
or the more basic
FROM microsoft/dotnet:2.0-sdk
COPY -–from=0 /app/out/ ./

Related

Creating Docker image for a dotnet 6 application - Type '' already defines a member called '' with the same parameter types

I am trying to create a docker image for a .net 6 web api application, and whenever I run the command:
~ sudo docker build -t aspnetapp .
It shows me the following error:
/src/AmplifyAPI.Application/Controllers/Product/ProductController.cs(22,38): error CS0111: Type 'ProductController' already defines a member called 'SaveProduct' with the same parameter types [/src/AmplifyAPI.Application/AmplifyAPI.Application.csproj]
And that error is getting showed for every method of every controller. This is my docker file:
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS base
WORKDIR /app
EXPOSE 80
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY . .
RUN dotnet restore "AmplifyAPI.Application/AmplifyAPI.Application.csproj" --disable-parallel
WORKDIR "/src/AmplifyAPI.Application"
COPY . .
RUN dotnet build "AmplifyAPI.Application.csproj" -c Release -o /app
FROM build AS publish
WORKDIR "/src/AmplifyAPI.Application"
RUN dotnet publish "AmplifyAPI.Application.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "AmplifyAPI.Application.dll"]
And the application structure is:
--src
-----Dockerfile
-----AmplifyAPI.Data
-----AmplifyAPI.Domain
-----AmplifyAPI.Application
---------Controllers
--tests
-----AmplifyAPI.UnitTests
-----AmplifyAPI.IntegrationTests
Locally the application builds just fine. I am using Linux as operating system.
You copy the source code into the container twice, in different locations. You also both build and publish to /app, which might cause issues.
The normal Dockerfile for a .NET project first copies the .csproj file, then does a restore and then copies the rest of the code and builds, like this
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS base
WORKDIR /app
EXPOSE 80
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY AmplifyAPI.Application/AmplifyAPI.Application.csproj ./AmplifyAPI.Application/
COPY AmplifyAPI.Data/AmplifyAPI.Data.csproj ./AmplifyAPI.Data/
COPY AmplifyAPI.Domain/AmplifyAPI.Domain.csproj ./AmplifyAPI.Domain/
RUN dotnet restore "AmplifyAPI.Application/AmplifyAPI.Application.csproj" --disable-parallel
COPY . .
RUN dotnet build "AmplifyAPI.Application/AmplifyAPI.Application.csproj" -c Release
FROM build AS publish
WORKDIR "/src"
RUN dotnet publish "AmplifyAPI.Application/AmplifyAPI.Application.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "AmplifyAPI.Application.dll"]

How to copy the contents from the previous directory in Dockerfile

Let's take an example of dotnet application code
I have an application code present at
D:\eshop\DotneteShopOnWeb\src\Web\Application.sln
and I have multiple projects in the "Application.sln" like Web, API, Test
every project is having its own Dockerfile like
D:\eshop\DotneteShopOnWeb\src\Web>Dockerfile
The Dockerfile is as below
FROM mcr.microsoft.com/dotnet/sdk:5.0-focal AS build
WORKDIR /app
COPY *.sln .
COPY . .
WORKDIR /app/src/Web
RUN dotnet restore
RUN dotnet publish -c Release -o out
FROM mcr.microsoft.com/dotnet/sdk:5.0-focal AS runtime
WORKDIR /app
COPY --from=build /app/src/Web/out ./
ENV ASPNETCORE_ENVIRONMENT Development
ENTRYPOINT ["dotnet", "Web.dll"]
I am executing the docker build command Dockerfile location.
I have also tried docker build -t dotnetcore-eshop-mvc-manual -f src/Web/Dockerfile . from D:\eshop\DotneteShopOnWeb>
I am getting errors in RUN dotnet restore as the sln file is not getting copied into the work directory.
Please let me know what modification I need in COPY to copy content from the previous directory.
you are changing the working directory before restoring. I mean that your .sln files are in the path /app but your restoring is executed inside /app/src/Web location. you should do something like this to copy .sln files.
COPY *.sln .
COPY . .
WORKDIR /app/src/Web
COPY . .
RUN dotnet restore
RUN dotnet publish -c Release -o out
FROM mcr.microsoft.com/dotnet/sdk:5.0-focal AS runtime
WORKDIR /app
COPY --from=build /app/src/Web/out ./
ENV ASPNETCORE_ENVIRONMENT Development
ENTRYPOINT ["dotnet", "Web.dll"]

Error message "Program does not contain a static 'Main' method suitable for an entry point"

I have an ASP.NET CORE app with a few projects inside and the following Dockerfile:
FROM microsoft/dotnet:2.2-aspnetcore-runtime AS base
WORKDIR /app
EXPOSE 80
FROM microsoft/dotnet:2.2-sdk AS build
WORKDIR /src
COPY src/Mbv.Vans.Core/Mbv.Vans.Core.csproj Mbv.Vans.Core/
COPY src/Mbv.Vans.Common/Mbv.Vans.Common.csproj Mbv.Vans.Common/
COPY src/Mbv.Vans.Api/Mbv.Vans.Api.csproj Mbv.Vans.Api/
RUN dotnet restore Mbv.Vans.Api/Mbv.Vans.Api.csproj
COPY . .
FROM build AS publish
RUN dotnet publish Mbv.Vans.Api/Mbv.Vans.Api.csproj --no-restore -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "Mbv.Vans.Api.dll"]
On line RUN dotnet publish Mbv.Vans.Api/Mbv.Vans.Api.csproj --no-restore -c Release -o /app When it tries to build the project, it fails with error:
"Program does not contain a static 'Main' method suitable for an entry point"
Here is my .csproj file:
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp2.2</TargetFramework>
<GenerateDocumentationFile>true</GenerateDocumentationFile>
<NoWarn>1591</NoWarn>
<GenerateProgramFile>false</GenerateProgramFile>
</PropertyGroup>
I searched a lot of questions regarding this issue and divide it into the following resolutions:
COPY . . is not fixing this issue
I have only one static void main
<GenereteProgramFile> false doesn't help.
Could someone can help me to beat this awfull issue?
So, I ran across this same issue and drove me insane. The solution here is to skip the build and go right to a publish.
I was helped by looking at this particular sample: https://github.com/dotnet/dotnet-docker/blob/master/samples/aspnetapp/Dockerfile.alpine-x64
As you can see in there, there is no build occurring. There is a restore, and then a publish. Why no build? I don't know. I'm investigating, but I'm happy it worked for me at least. Let me know how it goes.
Edited for additional info:
Here is the original non-working Dockerfile:
FROM microsoft/dotnet:2.2-aspnetcore-runtime-nanoserver-1809 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443
FROM microsoft/dotnet:2.2-sdk-nanoserver-1809 AS build
WORKDIR /src
COPY ["mercurynorth_netcore/mercurynorth_netcore.csproj", "mercurynorth_netcore/"]
RUN dotnet restore "mercurynorth_netcore/mercurynorth_netcore.csproj"
COPY . .
WORKDIR "/src/mercurynorth_netcore"
RUN dotnet build "mercurynorth_netcore.csproj" -c Release -o /app
FROM build AS publish
RUN dotnet publish "mercurynorth_netcore.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "mercurynorth_netcore.dll"]
...and here the the newly working Dockerfile:
FROM mcr.microsoft.com/dotnet/core/sdk:2.2-alpine AS build
WORKDIR /app
# Lets do a restore of the NuGet packages, and then restore the app in a container.
COPY mercurynorth_netcore.csproj ./
RUN dotnet restore "mercurynorth_netcore.csproj"
COPY . .
RUN dotnet publish "mercurynorth_netcore.csproj" -c Release -o /app
FROM mcr.microsoft.com/dotnet/core/aspnet:2.2 AS final
WORKDIR /app
EXPOSE 80
EXPOSE 443
COPY --from=build /app .
ENTRYPOINT ["dotnet", "mercurynorth_netcore.dll"]
As you can see, what I generally did was remove the line:
RUN dotnet build "mercurynorth_netcore.csproj" -c Release -o /app
...as well as do some clean-up.
The general take-away is that running the build command on my dev machine(s) will work fine, but as part of building the container, it will fail.

Docker image doesnt work - probably wrong paths on build

I'm trying to move ASP.NET Core project to docker linux container, however I cannot build up a proper image. When I create default dockerfile (through VisualStudio Add -> DockerSupport) it's setting up paths for COPY to all of the projects. However when I run docker build -t . it pop's out error "no such file or directory". I've tried to stick with official docker documentation with moving asp.net core to docker containers and here is the code I ended with:
FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443
FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /src
COPY ./ ./
RUN dotnet restore "myproject.csproj"
COPY . .
WORKDIR "/src/myproject"
RUN dotnet build "myproject.csproj" -c Release -o /app
FROM build AS publish
RUN dotnet publish "myproject.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "myproject.dll"]
This is the command im using to build up an image:
docker build -t myapp -f myproject/Dockerfile .
I'm building it from the parent directory, because when I was using current working directory it wasn't finding all the .csproj files. When I run this image it doesn't work - I know there are wrong paths, however I have no idea where is the error in logic. Current error is "Program does not contain a static 'Main' method suitable for an entry point" and "A fatal error was encountered. The library 'libhostpolicy.so' required to execute the application was not found in '/app/'. Failed to run as a self-contained app. If this should be a framework-dependent app, specify the appropriate framework in /app/myproject.runtimeconfig.json"
Try the following based off this documentation replace myproject with project name
FROM microsoft/dotnet:sdk 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 microsoft/dotnet:aspnetcore-runtime
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", “myproject.dll"]
Then build and run with the following commands:
docker build -t myproject .
docker run -d -p 8080:80 --name myapp myproject
You should not specify RUN dotnet build "myproject.csproj" -c Release -o /app with -o /app which will output in the same folder with build layer.
Try
FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443
FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /src
COPY ["myproject/*.csproj", "myproject/"]
RUN dotnet restore "myproject/myproject.csproj"
COPY . .
WORKDIR /src/myproject
RUN dotnet build "myproject.csproj" -c Release -o /app
FROM build AS publish
RUN dotnet publish "myproject.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "myproject.dll"]

How to change multi-step docker to one-step docker build?

I should convert this multi-step docker action (generated in VS2017) to one step action:
FROM microsoft/aspnetcore:2.0-nanoserver-1709 AS base
WORKDIR /app
EXPOSE 80
FROM microsoft/aspnetcore-build:2.0-nanoserver-1709 AS build
WORKDIR /src
COPY *.sln ./
COPY Micro/Micro.csproj Micro/
RUN dotnet restore
COPY . .
WORKDIR /src/Micro
RUN dotnet build -c Release -o /app
FROM build AS publish
RUN dotnet publish -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "Micro.dll"]
Can anyone help?
You may use something like docker-compose (https://docs.docker.com/compose/) to maintain several dockers.

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