COPY command failing when running DOCKER BUILD - docker

Question

I'm trying to create a Docker image but it's not working. I'm trying to run this Docker command from the CLI and I'm getting the following error:
(from the <repo root>/src/Services/Accounts/Accounts.Api)
> docker build .
Error message:
Step 7/18 : COPY ["src/Services/Accounts/Accounts.Api/Accounts.Api.csproj", "src/Services/Accounts/Accounts.Api/"]
COPY failed: stat /var/lib/docker/tmp/docker-builder937056687/src/Services/Accounts/Accounts.Api/Accounts.Api.csproj: no such file or directory
and here's my Dockerfile
FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
WORKDIR /app
EXPOSE 80
FROM microsoft/dotnet:2.1-sdk AS build
WORKDIR /src
RUN ls -al
COPY ["src/Services/Accounts/Accounts.Api/Accounts.Api.csproj", "src/Services/Accounts/Accounts.Api/"]
COPY ["src/Services/Accounts/Accounts.Api/NuGet.config", "src/Services/Accounts/Accounts.Api/"]
RUN dotnet restore "src/Services/Accounts/Accounts.Api/Accounts.Api.csproj"
COPY . .
WORKDIR "/src/src/Services/Accounts/Accounts.Api"
RUN dotnet build "Accounts.Api.csproj" -c Release -o /app
FROM build AS publish
RUN dotnet publish "Accounts.Api.csproj" -c Release -o /app
FROM base AS final
WORKDIR /app
COPY --from=publish /app .
ENTRYPOINT ["dotnet", "Hornet.Accounts.Api.dll"]
I've also tried running this from the repo root directory:
> docker build .\src\Services\Accounts\Accounts.Api
Why is it trying to find my files in some /var/lib/docker/tmp/blah folder?
Further info:
Windows 10 OS
Docker CE with Linux Containers
VSCode

Answer 1

I think we can solve this by clarifying how to use the build context and how to specify the location of the Dockerfile.
The Docker build command usage looks like this:
docker build [OPTIONS] PATH
Your build context is the location that you define with PATH, Docker can use the files in the build context for the build. (You cannot use files outside the build context for the build.)
In the Dockerfile in your COPY statements you are specifying the source files' location relative to the root of your repo. This implies that
You should run your build command from the <root of your repo> with PATH . like this:
docker build .
You have not specified the path of your Dockerfile in the question, but it seems to me that it's in a subfolder of your repo. To make your build work issue the docker build command from the <root of your repo> like this:
docker build -f <path to Dockerfile> .
Your Dockerfile must be in the build context.
I think getting the build context and the location of the Dockerfile right will fix your build.
Also remember to use the -t flag to tag your image.
Why is it trying to find my files in some /var/lib/docker/tmp/blah folder?
As you probably know, Docker uses a Linux VM under the hood in the Docker for Windows app to develop Linux based containers. This location simply refers to the location in the VM.