Devcontainer doesn't work on a folder mounted in WSL

[ThePlenkov]

Hi,

Let me please explain the situtation:

• I have workspace with all projects stored in the external ext4 vhdx file
• I have mounted it via wsl --mount command to all wsl distros wsl --mount --vhd "$PSScriptRoot\ws.vhdx" --partition 1 --name workspace
• When I "Open in container" from /mnt/wsl/workspace/myapp folder container starts but filetree is empty

However when I run a command like this:

docker run -it --rm --mount "source=$(pwd),target=/workspace,type=bind" ubuntu bash

all the files are shown, and changes in that folder are attracted in my workspace folder in WSL ( which is mounted vhdx )

So I make the assumption that something is wrong here with how VS code is binding this folder to a devcotnainer

[ThePlenkov]

here is my devcontainer.json

{
  "name": "Node.js & TypeScript",
  "workspaceFolder": "/workspace",
  "workspaceMount": "source=${localWorkspaceFolder},target=/workspace,type=bind",
  "build": {
    // Path is relative to the devcontainer.json file.
    "dockerfile": "Dockerfile"
  }

i tried with workspace mount and wihtout..

[ThePlenkov]

Actually, I have inspected created devcontainer and see there that my source folder is something like mnt/wsl/workspace/git_projects/myapp and I used to work in a symlinked folder ~/git_projects/myapp which is pointing to /mnt/workspace..

And what is very interesting.
This command works in :

:~/git_projects/fs-observability-aws$ docker run -it --rm --mount "source=$(pwd),target=/workspace,type=bind" ubuntu ls /workspace

and this not

cd  cd $(realpath $(pwd))
docker run -it --rm --mount "source=$(pwd),target=/workspace,type=bind" ubuntu ls /workspace

I honestly do not have any explanations why.

[ThePlenkov]

OK a bit more updates:

What I noticed - that if I use dockerfile directly - it's always mounting real path like /mnt/workspace ..

However when I switched to compose - it started using the path /home/pplenkov/git_projects/myapp:/workspace:rw with symlink and it started working as expected:

So most likely this is the issue for docker itslef why it happens like this.

[ThePlenkov]

So may be what can be improved for VS Code extension - do not resolve to real path the path which we use for binding the workspace in WSL if Dockerfile is used.

[chrmarti]

Which path do you get for pwd in a terminal in this folder in VS Code in WSL?

[ThePlenkov]

It depends.. if open from ~/path then is /home/myuser/path

While at same time if I go to /mnt/wsl/path - it will be same folder

Because of symlink.

I think it should be possible to reproduce in any wsl since mnt/c is available everywhere

[ThePlenkov]

I also found another problem. If docker compose is running only from symlinked folder ( which is most likely docker issue )

If I go to typescript debugging- all my links are broken and sourcemaps do not work - they all resolved against real path

While if I go to real /mnt path - I can debug from that project, but cannot mount to docker 😞

[ThePlenkov]

What I noticed also, I added following section:

  "remoteEnv": {
    "hostLocalWorkspaceFolder": "${localWorkspaceFolder}",
  }

so in the container - it's always a real path, but docker uses different bound types when binding from symlinked folder .

It's hostFile in one case and wsl2DistroFile in another.

I described it also here: docker/for-win#14380

[ThePlenkov]

What could probably help is to use: ${localEnv:PWD} instead of ${localWorkspaceFolder}, but it doesn't work. always empty

[ThePlenkov]

@chrmarti do you think it is possible to change the logic of localWorkspaceFolder and to use the actual host OS path, not resolved realpath? Or may be we can introduce one more variable to avoid regression issue.

[FloSch62]

I having the same problem I would like my devcontainer.json to be

"workspaceFolder": "${localWorkspaceFolder}",
"workspaceMount": "source=${localWorkspaceFolder},target=${localWorkspaceFolder},type=bind"

as I need it for orbstack and so, but on Windows it only works if I do:

"workspaceFolder": "/workspace",
"workspaceMount": "source=${localWorkspaceFolder},target=${localWorkspaceFolder},type=bind"

But that workaround for windows, does than not work anymore in orbstack and others.... And I would like not to maintain two devcontainer files...

[chrmarti]

This seems to be a Docker issue: docker/for-win#14380