action.yml

name: Setup WSL2
description: Enable WSL2 and install a Linux distro in GitHub-hosted runners.
author: Vedant Mohan Goyal
branding:
  icon: terminal
  color: blue
inputs:
  distro:
    description: Linux distro to install. Default is Ubuntu.
    required: true
    default: Ubuntu
  enable-systemd:
    description: |
      Enable systemd support. Default is true.
      Note: Please disable this if you are using `windows-2019` runner.
    required: true
    default: 'true'
runs:
  using: composite
  steps:
    - if: runner.os != 'Windows'
      run: |
        echo "This action is only supported on Windows runners"
        exit 1
      shell: bash
    - if: inputs.enable-systemd == 'true' && inputs.distro != 'none'
      run: |
        # check if systemd is supported
        if ((Get-ComputerInfo -Property OsName).OsName.Contains('2019')) {
          Write-Output 'systemd is not supported on windows-2019 runners.'
          exit 1
        }
      shell: pwsh
    - run: |
        # update WSL, download & install ${{ inputs.distro }}
        wsl --set-default-version 2; wsl --update; wsl --status;
        if ('${{ inputs.distro }}' -eq 'none') {
          Write-Output 'Skipping distro installation...'
          return
        }
        $distros = (Invoke-RestMethod -Uri https://raw.githubusercontent.com/microsoft/WSL/refs/heads/master/distributions/DistributionInfo.json).Distributions
        if ($distros.Name -notcontains '${{ inputs.distro }}') {
          Write-Output 'Invalid distro: ${{ inputs.distro }}'
          Write-Output 'The value should be one of the following:'
          wsl --list --online
          exit 1
        }
        # github runner does support windows arm64 runners, so we don't need to check the architecture
        $distroDownloadUrl = $distros.Where({ $_.Name -eq '${{ inputs.distro }}' }).Amd64PackageUrl
        Set-Location $env:GITHUB_WORKSPACE\..\.. # don't download in $env:GITHUB_WORKSPACE
        $filename = "${{ inputs.distro }}$([System.IO.Path]::GetExtension($distroDownloadUrl))"
        Write-Output 'Downloading and installing the distro...'
        Invoke-WebRequest -Uri $distroDownloadUrl -OutFile $filename
        if ($filename.EndsWith('.appxbundle', [System.StringComparison]::OrdinalIgnoreCase)) {
          Expand-Archive -Path $filename -DestinationPath .\AppxBundle
          Remove-Item -Path $filename -Force # cleanup so we don't fill up the disk unnecessarily
          $filename = (Get-ChildItem -Path .\AppxBundle -Filter *x64*).FullName
        }
        Expand-Archive -Path $filename -DestinationPath .\
        Remove-Item -Path .\AppxBundle -Recurse -Force -ErrorAction SilentlyContinue # cleanup
        # exclude the extra splash and setup exe files that come with "ubuntu" and "ubuntu-22.04" distros
        $distroExe = (Get-ChildItem -Path . -Filter *.exe).Where({ $_.Name -notmatch 'splash|setup' }).FullName
        & $distroExe install --root
        if ('${{ inputs.enable-systemd }}' -eq 'true') {
          Write-Output 'Enabling systemd support...'
          @'
        [boot]
        systemd=true
        '@ | Out-File -FilePath .\wsl.conf -Encoding utf8
          wsl --distribution ${{ inputs.distro }} --cd $(Get-Location) cp wsl.conf /etc/wsl.conf
          Write-Output 'Restarting WSL...'
          wsl --shutdown
          # https://learn.microsoft.com/en-us/windows/wsl/wsl-config#the-8-second-rule-for-configuration-changes
          # although the documentation says 8 seconds, we wait for 10 seconds to be safe
          Start-Sleep -Seconds 10
        }
        Write-Output 'Running command to test the installation...'
        Write-Output '-> cat /etc/os-release'
        wsl --distribution ${{ inputs.distro }} cat /etc/os-release # print the distro info
        # add a wrapper script to run commands inside wsl easily using run.shell in github workflows
        @'
        @echo off
        FOR /F "usebackq tokens=*" %%F IN (`wsl wslpath '%~1'`) DO SET wslpath=%%F
        wsl -d ${{ inputs.distro }} sed -i 's/\r$//' %wslpath%
        wsl -d ${{ inputs.distro }} --cd %GITHUB_WORKSPACE% bash --noprofile --norc -eo pipefail %wslpath%
        '@ | Out-File -FilePath $env:RUNNER_TEMP\wsl-run.bat -Encoding utf8
        $env:RUNNER_TEMP >> $env:GITHUB_PATH
      shell: pwsh