Support rootless, daemonless podman inside WSL

[Clockwork-Muse]

Since the changes to Docker's licensing, I've been looking at using Podman to run my devcontainers instead of Docker. There's a couple of wrinkles to this, however; by default Podman is daemonless, and doesn't have a running service. This is actually a benefit to running in WSL (which doesn't have systemd by default), but means that accessing it via a remote CLI requires setting up a bunch of other services.

My preferred setup would be;

• Install podman in WSL. There are old instructions (although note that the config file name has changed)
• Install nothing on the Windows side. In the above install, there's no running service, and no unix socket either.

... and have everything "just work" (ie, container and image list).

The remote-containers extension solved this by running cli commands inside WSL.

[PavelSosin-320]

There are many benefits in using rootless Podman but not listed above:

1. Podman is serverless but not serviceless. Podman service can be started as systemd service. It can run every container as a service root or rootless.
2. Systemd is a part of most Linux distros supported by Podman.WSL doesn't use systemd as a init system but the ways to do it exist: systemd-genie from Arkane system.
3. Podman is the CLI toolset that consists of Podman, Buildah, and Skopeo packages that speed up Image development.
4. It is not scalable - using one Podman by several users in parallel is hardly possible. Every regular Linux desktop GUI or remote user has all resources available for his/her user session unless the container uses the system resources available only to root.
5. Podman remote client and Docker client have many common features but the key features used in the development are completely different. Service point configuration is different.
6. Podman REST API extends Docker REST API but they are not equivalent. It doesn't ensure that Docker's client will work exactly in the same way with Podman and Docker including storage, networking, SSH support, port forwarding via docker-proxy, etc. Podman offers a very fast and convenient but very minimalistic runtime with a focus on image and pod development.

[bwateratmsft]

I think we will need to work on as generic a solution as possible given the variety of container runtimes possible.

[bwateratmsft]

Probably related to microsoft/vscode-docker#3263.

[jankap]

Is there any chance to just run commands in WSL, as it's possible with the remote-containers extension, too?

[bwateratmsft]

@jankap You may find some success with the docker.dockerPath setting, e.g. setting it to something like "\"wsl -- docker\"", but I'm not completely sure. It is something we are actively working on.