Dockerfile - how to replace file inside container when run docker build command

General Discussions
1

Hello. I am new to Docker.
I have a standard Dockerfile that VS made for a .net Core MVC project.
Here it is:

#See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging.

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

FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build
WORKDIR / src
COPY ["EG_TESTIMAGE / EG_TESTIMAGE.csproj", "EG_TESTIMAGE /"]
RUN dotnet restore "EG_TESTIMAGE / EG_TESTIMAGE.csproj"
COPY. ...
WORKDIR "/ src / EG_TESTIMAGE"

RUN dotnet build "EG_TESTIMAGE.csproj" -c Release -o / app / build

FROM build AS publish
RUN dotnet publish "EG_TESTIMAGE.csproj" -c Release -o / app / publish


FROM base AS final
WORKDIR / app
COPY --from = publish / app / publish.

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

I am using nlog. There are two configuration files nlog.config and nlog.config.development.
When running docker build command, I need to copy nlog.config to nlog.config.development. (For correct operation of logs on the server with ASPNETCORE_ENVIRONMENT = development)

I am trying to make the command:

COPY nlog.config nlog.config.development - fails.

How to do it correctly?

2

This is the strangest Dockerfile I have ever seen, but how does your copy fail? Is there an error message or you just cannot find the file inside the container?

3

This is standard file by Visual Studio. Here is the link Customize Docker containers in Visual Studio - Visual Studio (Windows) | Microsoft Learn what describe this file.

4

Thank you for the link. The code you inserted is different. The version in the documentation has a correct syntax. Although I cannot help without an error message. The problem could be how you refer to the file on the host with an incorrect path or can be anything else.