Support container operations on Windows runners

[tprk77]

Describe the enhancement

I would like to run a Windows Docker container on a Windows runner. But was surprised to find out that this is not supported:

Error: Container operations are only supported on Linux runners

Specifically, I am asking that:

• jobs.<job_id>.container work on Windows runners
• It allows for use of Windows containers (as opposed to Linux containers)

Code Snippet

Here's an example workflow of what I'm asking for:

jobs:
  windows-build:
    name: Windows Build
    runs-on: windows-2019
    container:
      image: mcr.microsoft.com/windows/servercore:ltsc2019
    steps:
      - run: ...

Additional information

N/A

[TingluoHuang]

@tprk77
we are not supporting windows container for the following reasons:

• Extra windows version requirements, ex regular windows 10 desktop may not work with certain network/volume features
• We can't install docker-ce on GitHub windows hosted runner VM due to license issues.
• We have to install docker-ee which is usually 6-12 months behind docker-ce on feature and bug fixes.
• Container on Linux and Windows are not feature parity.
• Windows is just not good at supporting containers.

[tprk77]

That's too bad, but it seems there is good justification for not supporting Windows container.

However, I don't see why this isn't mentioned in the documentation of jobs.<job_id>.container. It would be really easy to include a line saying that it only works on Linux runners, and would prevent people form wasting their time trying to use it like I did.

Should I open another ticket for the documentation?

[jelmansouri-legion]

Is Microsoft, improving/planning on maintaining container support or is the plan to deprecate it at some point? If the latter I understand it's not worth the time of devs and GitHub. If not, maybe even with some restrictions, it might be worth allowing some workflow to used them, as long as the non supported cases are documented.
Since the documentation wasn't explicit about the ability to use the container operations on windows, I gave it a try. It yielded the same reported error above. As a workaround, I ended up doing this:

      - name: Build
        run: >-
          docker run
          --name cargo_test
          --rm
          --workdir ${{ matrix.workdir }}
          -v ${{ github.workspace }}:${{ matrix.workdir }}
          ${{ matrix.container }}
          cargo test --no-run