Support container operations on Windows runners

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

[neersighted]

Hi, I’m an engineer who works on the product formerly known as Docker EE (and now known as Mirantis Container Runtime). We work in the upstream Moby project on a daily basis to ensure our product is as close to upstream Moby as possible, and count several maintainers among our team.

I’d love to understand why GitHub needs MCR (Docker EE) over a from-source build of Moby. I’d also love to determine if we can do something as Mirantis to help GitHub support this for all open-source projects. If you’re from GitHub, please reach out – I’d be very happy to discuss upstream Moby and its development process/licensing, MCR’s lifecycle (we usually deliver patches in a matter of weeks, but historically version numbers have not been aligned, and this may be the source of confusion), and any other questions/concerns you may have.

[thecloudtaylor]

@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.

@TingluoHuang - I am the group product manager for Windows containers. I disagree with a set of these assertions and very much disagree with the over decision as clearly from this discussion and many others we have had there is customer need for this support.

To the points: #1 (Win 10 etc…) - Firstly, I’m not sure why this is even relevant to the discussion. While of course developers leverage Windows client while building applications the build pipeline and production usage of them is on Windows Server.

#2 (Docker CE) - You can use Moby (to @neersighted’s point).

#3 (MCR delays) - I would be very interested to understand what features fixes, specific to Windows containers, you where delayed on? The Mirantis team has typically been very active at incorporating blocking issues into EE builds.

#4 (feature parity) - The first priority/goal of Windows containers is enabling customers a part forward for there Windows Server applications. There are definitely features on our roadmap that will enhance that further but we believe and have many customers in production that have been very successful moving apps forward. There are a whole host of Linux features/functionality that just simply don’t make since in a Windows world. Just as there are Windows features that don’t make since in a linux world.

#5 (windows is not good at hosting containers) - I’m just going to leave this at argumentative and unproductive.