docker-multistage-build-publish-dotnet-core

Basic example to build an publish dotnet core core apps and packages to npm repo

Docker prepare build stages

Base image for final step

FROM mcr.microsoft.com/dotnet/aspnet:5.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

Base image for build and publish steps

FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build
WORKDIR /src
RUN apt-get install -y tar zip 

How the build functions

Create build.sh file to control the build.

set -eux
set echo off
# tarball csproj files, sln files, and other project files
find . \( -name "*.csproj" -o -name "*.sln" -o -name "NuGet.config" \) -print0 | tar -cvf projectfiles.tar --null -T -

#Trigger docker build and pass in the required build arguments for details like api keys for npm server
docker build --tag app:1.0.0 --build-arg api_key=mykey --build-arg version="1.0.0" .

#Remove the tarball once build is done
rm projectfiles.tar

Restore only nuget packages.

This allows for the initial build stage to only restore nuget packages for the solution. and when rebuild is triggered this step will be executed from cache until we add new dependencies to the projects.

COPY projectfiles.tar .
# Extract the tarball to recreate the project structure without the source code.
RUN tar -xvf projectfiles.tar

# Runt the actual restore.
RUN dotnet restore

Build the solution

COPY . .
RUN dotnet build --no-restore

Publish the solution

FROM build AS publish

ARG api_key
ARG version

RUN dotnet publish --no-restore "./Presentation/MyApp.csproj" -o /app/publish

# publish and upload application to nexus server

RUN zip -r myApp.zip /app/publish   
RUN curl -v -u user:password --upload-file myApp.zip http://nexusserver/repository/develop/myApp.zip

# Package and publish libraries to nexus server
RUN dotnet pack -c Release -o /app/packages --no-restore --version-suffix $version
RUN dotnet nuget push "/app/packages/*.nupkg" --skip-duplicate --source http://nexusserver/repository/nuget/ --api-key $api_key

Prepare for container registry

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "MyApp.dll"]