Visual Studio Docker Support - Debugging with a Dockerfile outside of the startup project folder

Question

I have a docker file for a .NET Core project that references some library projects in the same solution.

Given that Docker does not allow copying files from outside of the parent directory (Docker: adding a file from a parent directory), I have to keep my Dockerfile outside of the executable (start up) project directory.

So, how do I use Visual Studio debugging with a Dockerfile that is not located within the executable project?

It seems that Visual Studio only works with the Docker debug profile if it can find a Dockerfile in the directory for the startup project.

When the Dockerfile is not present in the startup directory, the build error points at lines in a file named Container.targets, located at:

C:\Users<user>\.nuget\packages\microsoft.visualstudio.azure.containers.tools.targets\1.4.10\build

<Target Name="ContainerPrepareForLaunch" Condition="Exists('$(ContainerSemaphoreFilePath)')">
    <PrepareForLaunch DevelopmentMode="$(ContainerDevelopmentMode)"
                      DevEnvDir="$(DevEnvDir)"
                      Dockerfiles="@(_Dockerfile)" 
                      IntermediateOutputPath="$(ContainerIntermediateOutputPath)"
                      ProjectCapability="@(ProjectCapability)"
                      ProjectFilePath="$(MSBuildProjectFullPath)" 
                      NuGetPackageFolders="$(NuGetPackageFolders)"
                      NuGetPackageRoot="$(NuGetPackageRoot)"
                      TargetFrameworkWithVersion ="$(TargetFramework)"
                      TargetPath="$(TargetPath)"
                      ErrorLogFilePath="$(ContainerSemaphoreFilePath)"
                      DockerLabelBuiltImages="$(DockerLabelBuiltImages)"
                      DockerImageLabel="$(DockerImageLabel)" 
                      ProjectTypeGuids="$(ProjectTypeGuids)" />
  </Target>

However I need to be able to manage the path to the Dockerfile on a per-project basis.

Not sure what you've done, but this should work out of the box. It's not about where the Dockerfile is, it's about from where docker is called to build it. It is for this reason that Visual Studio actually runs the docker commands from the solution root, not the project folder, as from the solution root, you'll generally have access to all the projects you'd need to copy in. — Chris Pratt, Jul 02 '19 at 17:06
Chris you are correct. Despite the Docker file being under the project directory, it is in fact executed in the solution directory. Thanks. — gbro3n, Jul 04 '19 at 06:26

score 12 · Answer 1 · answered Sep 13 '19 at 17:21

12

You can specify DockerfileFile in your project file. The list of available recognized properties can be found here

answered Sep 13 '19 at 17:21

pikausp

1,142
11
31

3

This worked for me. VS created the Dockerfile in the same directory as the csproj file. In order to use the same file for my gitlab CI pipeline without changing it, I needed to move it up one directory so it was in the same directory as the solution file. Adding `..\Dockerfile` to the `PropertyGroup` fixed this for me so now I'm able to run the dubugger – NeXtMaN_786 Dec 01 '19 at 13:41

score -1 · Answer 2 · answered Jul 03 '19 at 05:36

For Dockerfile, you could only access the files in the parent folder. For Docker for VS debugging, it will access the dockerfile in the project root folder. You could not change this behavior.

For a workaround, you may consider adding docker-compose which could specicify the dockerfile location and run from VS directly.

Right-click the project in Solution Explorer and select Add > Container Orchestrator Support.
Choose Docker Compose

Modify docker-compose.yml to change the dockerfilepath in dockerfile variable

version: '3.4'

services:
hellodockertools:
    image: ${DOCKER_REGISTRY}hellodockertools
    build:
    context: .
    dockerfile: HelloDockerTools/Dockerfile

Set docker-compose as startup project

Visual Studio Docker Support - Debugging with a Dockerfile outside of the startup project folder

2 Answers2