How can I copy a .dll file into a docker image?

Question

I have a big problem: I have to copy a .dll file into my Docker Image. I can't pull it from NuGet, because it's a private package and you can't pull it normally via a url and nuget.config. I asked my colleagues and they said I should copy the file into the Docker Image. Does someone have an idea how to do it?

I have copied this .dll file into my normal project directory. But I have no idea where to copy it or how to do that.

This is my DockerFile:


FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
WORKDIR /app
EXPOSE 80

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
WORKDIR /src
COPY ["DoKiva/DoKiva.csproj", "DoKiva/"]
RUN dotnet restore "DoKiva/DoKiva.csproj"
COPY . .
WORKDIR "/src/DoKiva"
RUN dotnet build "DoKiva.csproj" -c Release -o /app/build

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

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

If you could help me I would really appreciate it!

My Docker Build Command is docker build -t dokivac .

You can add a link to this dll to `csproj` file and set `CopyAlways`. Then it'll be copied to output directory during build — Pavel Anikhouski, Dec 04 '20 at 09:41
Thanks! Where can I edit the .csproj and what do I have to add sorry I'm kind of new to C# and Docker. — MaxinhoHD, Dec 04 '20 at 09:47
[Including linked files from outside the project directory in ASP.NET Core](https://andrewlock.net/including-linked-files-from-outside-the-project-directory-in-asp-net-core/) one of the first results in google — Pavel Anikhouski, Dec 04 '20 at 09:49
Is it maybe an idea to first build the project normal and then later pack into Docker? — MaxinhoHD, Dec 04 '20 at 11:00
Did you try creating a nuget package from the dll. Refer: https://stackoverflow.com/q/43277715/3312570 — Ziaullah Khan, Dec 04 '20 at 11:27

score 0 · Answer 1 · answered Dec 04 '20 at 09:43

0

The COPY command is what does this. It's first parameter is the source, relative to the Dockerfile and the second is the destination, relative to the current WORKDIR. You can use it to copy entire folders or single files. However as build is being run, have you tried just importing the DLL in your Visual Studio project, selecting properties and than copy the file as a build action. This way the DLL will be automatically moved to your build directory?

answered Dec 04 '20 at 09:43

Peter Georgiev

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I tried this but the problem was even tough I copied the file dotnet restore still tried to reinstall this package. – MaxinhoHD Dec 04 '20 at 09:48
Or do I have to copy the file into a specific directory? – MaxinhoHD Dec 04 '20 at 09:50
You mentioned that the package is not available in a nuget feed, why is the restore trying to reinstall it? – Peter Georgiev Dec 04 '20 at 09:58
I have no idea. – MaxinhoHD Dec 04 '20 at 10:55

How can I copy a .dll file into a docker image?

1 Answers1