Generic DotNet Dockerfile using BuildKit `RUN --mount` directive to keep csproj structure.

.dockerignore

# This is an example of what you might have in your .dockerignore. Some items can be omitted like `!/test/**` or added
# like `**/node_modules` if you have a node/frontend project.
*
!/*.sln
!/nuget.config
!/src/**
**/bin
**/obj

Dockerfile

#syntax=docker/dockerfile:1.2

#######################################
## This Dockerfile requires BuildKit ##
#######################################

## Build Stage
FROM mcr.microsoft.com/dotnet/sdk:5.0 as build
## Build stage arguments
ARG CONFIG_PROFILE=Release
ARG PROJECT_DIR
ARG PROJECT_NAME

ENV PROJECT=${PROJECT_DIR}/${PROJECT_NAME}.csproj
WORKDIR /app

COPY nuget.config* ./
COPY *.sln ./

## Copy .csproj files into the correct file structure
SHELL ["/bin/bash", "-O", "globstar", "-c"]
RUN --mount=target=docker_build_context \
cd docker_build_context;\
cp **/*.csproj ../ --parents;
RUN rm -rf docker_build_context
SHELL ["/bin/sh", "-c"]

## Restore project
RUN dotnet restore ${PROJECT}
## Copy all files if restore succeeds
COPY . ./
## Publish project without restoring
RUN dotnet publish --no-restore -c ${CONFIG_PROFILE} -o out ${PROJECT}

## New stage used to reduce the size of the final image ---
FROM mcr.microsoft.com/dotnet/aspnet:5.0
## Final stage arguments
ARG PROJECT_NAME

WORKDIR /app

COPY --from=build /app/out .
ENV ASPNETCORE_URLS=http://+:80

## Create a symlink so we can use exec form entrypoint
RUN ln -s ${PROJECT_NAME}.dll Entrypoint.dll

ENTRYPOINT [ "dotnet", "Entrypoint.dll" ]

It blew my mind that Docker build doesn't support globstar. I ended up using a combination of find and cpio.

find . -name *.csproj | cpio -pdm [wherever]

Do you think there's any advantage to the BuildKit + mount approach?