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Windows + Linux containers on Windows 2025 with WSL2 and Github Actions runner

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By Dawid Wozny
8 min read
Windows + Linux containers on Windows 2025 with WSL2 and Github Actions runner

Windows + Linux containers on Windows 2025 with WSL2 and Github Actions runner

Intro

This post will cover several side topics, so I’ll start by listing the main points and then dive deeper into a few key areas. Here’s what you can learn:

  • how to run Windows Server 2022 LTSC container on Windows Server 2025 LTSC with process isolation
  • how to run Windows Server 2025 LTSC container on Windows Server 2025 LTSC with process isolation
  • how to run MSSQL Linux container with WSL2
  • do all above on the same machine simultaneously
  • do it on GitHub action hosted agent windows-2025

If you are not interested in reading, you can just check the pipline here. You can fork it, if you like, and try it yourself. It works on mine 😆

Motivation

Weirdo

I hope nobody will get ofended but I think ‘we’ developers are a weird group of people. We get genuinely excited about things that most people find absolutely boring. Like, who cares about composition, dependency inversion or functional programing? Normal person thinks about inheritance at most! We spend days writing software for free on GitHub, while other people are out there enjoying life on other *Hub platforms… like Snapchat or TikTok 😆 And recently started to wonder if being weird in a group of weird people makes me O(n^2) weird or maybe normal? Why can I be consider weird among developers? I use Windows Containers. Yeah, and apart of people I showed this painfull path I don’t know anyone in person using it. Even Microsoft publish official image for MSSQL on Linux, not on Windows.😆 It’s like a secret club… with a really buggy entrance.

Being serious

Ok, as much as I could make fun of Windows Containers I use them. Why? Because as any container technology, they solve real problems. There are corner cases where you can’t use Linux and still want to benefit from containerisation. Is this post for somebody who want to learn Windows Containers? No. This post is for somebody who wan’t to get the most of Linux containers but still need to build on Windows.

When you are working with Linux containers, services like MSSQL, MongoDB, RabbitMQ, Nginx, actually any software you can imagine, can be up and running on your machine within a few seconds and I also include time to read sparse documentation.

Windows containers ecosystem is not so rich. When I begun my jurney with containers, Microsoft was still supporting developement images for MS SQL on Windows. You can check that Windows folder of this repo was not updated for the last 4 years. After that, started to develop own images for MSSQL and actually any infrastructure I required in test/dev environments.

Going forward I hope, I will not need to do it anymore. The changes to Window Server should allow to run Linux containers on Windows without need for custom setup. That’s why I present this on GitHub action hosted agent. Which is still in beta but availible for anyone to use.

Windows Server 2025 LTSC

Windows Server 2025 has been generaly availible since 4th of November 2024 and it is being shiped with a few features I am actually excited about (and related to this post).

WSL2

WSL in general allows you to run a Linux environment on Windows and WSL2 has significant performance improvemts in relation to WSL1. What is most important, it allows you to run Linux docker containers on Windows machine without the need for Hyper-V.

WSL2 was not included in Windows Server 2022 LTSC and only added to Windows Server 2022 SAC some time after the release. This was quite important obstacle. When using Windows Containers you need to match the version of the operating system and the container and that is most of the time LTSC. At least how it was so far, although changed with Container Portability implementation.

So in theory I could have WSL2 on Windows Server 2022 but without Process Isolation for windows containers, no go.

With Windows Server 2025 relase you can run WSL2 off the shelf.

Winget preinstalled

For those who does not know that, Microsoft fianlly created a package manager called Winget which allows you to easily autmoate process instalation. It has been introduced in 2020, roughly after 15 years after dpkg. What a jurney! It was possible to add it to your system before but now it is delivered with the Windows Server 2025 base instalation.

Containers Portability

Containers Portability was something highly anticipated and makes Windows Containers working more like Linux ones where you don’t need to match exact version of container and host. It has actually been added to version 23H2 in July 2023 but it is first time being part of LTSC version.

Github Action windows-2025

As I mentioned earlier the setup was done on new GitHub Action runner windows-2025 as for now 2025-03-22 is still in beta.

Soulution

I have build a pipline in dedicated repo which you can fork and play yourself.

Here I will give some comments on the steps in pipeline:

Checkout with LFS

Wanted to make it a bit more usefull therfore added fake test database backup which is stored through Git LFS.

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- uses: actions/checkout@v4
    with:
        lfs: true

Install Linux

Instaling Linux distribution. It takes around 40 seconds.

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wsl --install Ubuntu

Prevent WSL shutdonw

Little trick to prevent WSL to shutdown automatically. By default when using wsl -- <command> syntax, WSL will shutdown automatically after a few seconds along with all containers.

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wsl -d Ubuntu  --exec dbus-launch true

Install docker on WSL

I had some issues with bash script created on windows. dos2unix did a trick. It takes around 40 seconds.

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wsl -- sudo apt-get update
wsl -- sudo apt-get install dos2unix
wsl -- dos2unix ./docker-install.sh
wsl -- ./docker-install.sh

docker-install.sh

It is copy paste of official docker instalation instruction.

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#!/bin/sh
# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc
# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "${UBUNTU_CODENAME:-$VERSION_CODENAME}") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update
# install docker
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin -y

Compose Up

I could just run docker run but wanted to make it a bit more interesting and restore db from backup. With compose it is just simpler. Prempting criticism: this setup meant to be simple not secure. Pulling and running takes below 60 seconds. Then I wait for database server to start being operational.

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wsl -- sudo docker compose pull -q  
wsl -- sudo docker compose -p test-setup up -d

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services:
  db:
    image: mcr.microsoft.com/mssql/server:2022-latest
    ports:
      - "1433:1433"
    environment:
     - MSSQL_SA_PASSWORD=SecretPassword9!
     - ACCEPT_EULA=Y
    volumes:
      - ./database/data:/var/opt/mssql/data
      - ./database/log:/var/opt/mssql/log
      - ./database/backup:/var/opt/mssql/backup
  web:
    image: nginx
    ports:
      - "8080:80"

Test curl inside WSL

Returns startup nginx content.

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wsl -- curl http://localhost:8080

Test request from Windows host

Returns the same output as curl.

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Invoke-WebRequest -Uri http://localhost:8080

Run initial test query

Note: Used address is 127.0.0.1 and not localhost. Had some issues with networking which I will be still investigating so it is not plain sailing.

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Invoke-Sqlcmd `
    -ServerInstance "127.0.0.1,1433" `
    -Database master `
    -Username "sa" `
    -Password "SecretPassword9!" `
    -TrustServer `
    -Query "SELECT name FROM sys.databases"

Restore database from backup

Backup folder is mounted during docker compose then need to run the following:

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Invoke-Sqlcmd `
    -ServerInstance "127.0.0.1,1433" `
    -Database master `
    -Username "sa" `
    -Password "SecretPassword9!" `
    -TrustServer `
    -Query "RESTORE DATABASE test FROM DISK = '/var/opt/mssql/backup/test.bak' WITH REPLACE;"

Run sample query on resored database

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Invoke-Sqlcmd `
    -ServerInstance "127.0.0.1,1433" `
    -Database test `
    -Username "sa" `
    -Password "SecretPassword9!" `
    -TrustServer `
    -Query "SELECT * FROM Person;"

Run Windows 2022 container

This is proof that you can run Windows Server 2022 image on Windows Server 2025 host. I have added flag --isolation=process just to be explicit about it but this command would normally fail anyway since GitHub runner does not have nested virutalisation and Hyper-V installed.

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docker run -d -p 8081:8080 --name aspnetcore_sample mcr.microsoft.com/dotnet/samples:aspnetapp-8.0-nanoserver-ltsc2022 --isolation=process

Run Windows 2025 container

There is no ASP.NET sample availible for 2025 therfore just run powershell command. Did not want to overcomplicate it with my own application.

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docker run --rm --isolation=process mcr.microsoft.com/windows/servercore:ltsc2025-amd64 powershell -Command "Write-Host 'Hello from the other side!'"

Test linux container still works

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Invoke-WebRequest -Uri http://localhost:8080

Test ASP.NET LTSC 2022 container works

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Invoke-WebRequest -Uri http://localhost:8081

Summary

That’s it. It is possible. GitHub runner is still in beta so this approach is not ready yet but looking forward using it soon. Don’t get me wrong here. I would not run Linux container on Windows in production unless Microsoft says explicitly it is supported. For building test/dev environments I am willing to give it a go.

DevOps, Docker
devops docker windows linux
This post is licensed under CC BY 4.0 by the author.