dockercoins: docker-compose up fails on WSL2

[mikeliddell-outreach]

I tried running on my WSL and go the following

$ git clone https://github.com/jpetazzo/container.training
$ cd container.training
$ docker-compose up
⠋ Container dockercoins_webui_1  Creating                                                                                                                                                   0.0s Error response from daemon: path /home/mliddell/k8s-training/k8s/container.training/dockercoins/webui/files is mounted on / but it is not a shared mount.

The problem & fix is as described in https://stackoverflow.com/questions/68273745/how-to-make-a-mount-shared-in-docker

• FIX: remove trailing slashes (/) from volumes definition.

Environment:

• WSL2, docker desktop
• Ubuntu host
• all previous demos working.. ie docker in good shape.

[jpetazzo]

Hey, thanks for identifying this!

Apparently, this is a bug in Compose v2 on WSL:

docker/compose#8558

I like to keep trailing slahes in volume mounts to show clearly that we're mounting directories (not files or sockets), but... If it breaks it on Windows, that sucks :(

I'm going to keep it like this for now, hoping that Compose will fix it soon; and if it doesn't fix it, then we'll change the Compose file of course.

Thanks again!

[jpetazzo]

I tried with the latest version of Docker Destkop on Windows (4.3.0, which includes Compose 2.2.0) and it seems to work with a trailing slash 🎉

I'd like to keep the trailing slash, because there are a few other places (in Docker and otherwise) where it's necessary, for instance:

• in a Dockerfile, using COPY with multiple files requires a trailing slash on the destination directory
• when using rsync, trailing slashes are also a way to ensure that no extra subdirectory is created (i.e. it's good practice to do rsync -av foo/ bar/)

I'm going to close this issue, but thanks a lot for reporting and tracking this, I truly appreciate it!