Below is the line-by-line explanation of our docker file we used in our experiment to build our image:
# Use the .NET SDK 7.0 as the base image for the build stage
FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
# Set the working directory inside the container
WORKDIR /app
# Copy the project files into the container's working directory
COPY . .
# Build and publish the application inside the container
RUN dotnet publish -c Release -o out
# Use the .NET Runtime 7.0 as the base image for the runtime stage
FROM mcr.microsoft.com/dotnet/runtime:7.0
# Set the working directory inside the container
WORKDIR /app
# Copy the published output from the build stage into the container's current directory
COPY --from=build /app/out .
# Specify the entry point command to run when the container starts
ENTRYPOINT ["dotnet", "HelloApp.dll"]
It's important to note that in the context of Docker, the .NET runtime is responsible for executing the specified DLL file. So, while it may seem unusual to specify a DLL file as the entry point in other contexts, within a Docker container running a .NET application, it is the appropriate approach to invoke the .NET runtime and execute the desired application code!