ASP.NET 5: docker build with multi-projects solution

Question

I'm trying to create an image of my ASP.NET 5 solution which is composed of 4 projects. Here is the structure:

• FlashTools (ASP.NET 5 class library)
• Models (ASP.NET 5 class library)
• QuizzCorrector (ASP.NET 5 Web Application)
• QuizzService (ASP.NET 5 class library)

I've a simple Dockerfile which looks like this:

FROM microsoft/aspnet

COPY . /app
WORKDIR /app
RUN ["kpm", "restore"]

EXPOSE 5004
ENTRYPOINT ["k", "kestrel"]

But not sure where to put it. In the root folder of my solution where a global.json is or in my Web Application folder where my project.json is? Of course I've modified it depending of where this file were located.

Anyway both seems to work because it download all the libraries I need when I run the command

docker build -t quizzcorrector .

My problem is at a moment docker tells me

Unable to locate Models >= 1.0.0

Unable to locate FlashTools >= 1.0.0

Unable to locate QuizzService >= 1.0.0

I've seen on this thread https://github.com/aspnet/aspnet-docker/issues/19 that in a multi-projects solution we should run the command "kpm pack" to pack my app into a deployable and runnable form.

I could not find any examples of Dockerfiles with the kpm pack command, only the documentation: https://github.com/aspnet/Home/wiki/Package-Manager

I've also tried of course to use ADD or COPY commands in my Dockerfile to copy the contents of my projects into the filesystem of the container, but still the same error.

Thank's for helping me

Answer 1

Updated: Feb 14, 2018

My previous answer doesn't take in account the best practices for writing Dockerfile. It also doesn't work for those solutions which have multiple web projects where each application must run in a separate Docker container. The better way would be to build and publish ASP.NET Core application in development environment and run the application in Docker container which is optimized for production use.

1. Create Dockerfile in the web application folder

2. Put the following content into it

   FROM microsoft/aspnetcore
   
   COPY ./publish /publish
   WORKDIR /publish
   EXPOSE 5000/tcp
   ENTRYPOINT ["dotnet", "QuizzCorrector.dll"]
   

3. Build and publish the project by running dotnet publish -c Release -o publish
4. Build Docker image by running docker build -t QuizzCorrector

Note that microsoft/aspnetcore Docker image is the runtime-only image which doesn't provide .NET Core SDK what makes it lighter and better for production use.

---

It might be late, but I'm going to answer this question for those who are still trying to get it working. You need to create a Dockerfile on solution level. Then you need to update your working folder to use the one where you web project is located. Here is below the final Dockerfile taking in account that kpm and k utilites were replaced with one dotnet tool.

FROM microsoft/dotnet:latest

COPY . /app
WORKDIR /app/src/QuizzCorrector
RUN ["dotnet", "restore"]

EXPOSE 5004
ENTRYPOINT ["dotnet", "run"]