Install-WslSwitchTask.ps1

<#
.SYNOPSIS
    Installs or removes the scheduled tasks that run Update-WslSwitch.ps1, so
    WSL2 bridged networking follows whichever network is connected.

.DESCRIPTION
    Install-WslSwitchTask.ps1 copies Update-WslSwitch.ps1 into -InstallDir and
    registers two tasks in the \WSL\ folder of Task Scheduler for the current
    user. Running it again replaces both tasks and the installed script, so
    use it to update the script or change settings.

    Run it from an elevated PowerShell opened under your own account, from
    the folder that holds Update-WslSwitch.ps1. If you elevate as a separate
    admin account, the tasks, .wslconfig path and install folder all belong
    to that account instead, and the script warns you.

    Tasks created:

      \WSL\Select Bridge Switch
          Runs Update-WslSwitch.ps1 with highest privileges, because
          Get-VMSwitch needs admin rights. Runs only while you are logged on,
          so it runs in your session against your WSL VM. Triggers:
            - at logon, after 45 seconds;
            - 15 seconds after a network connect or disconnect event
              (Microsoft-Windows-NetworkProfile/Operational 10000 and 10001);
            - 15 seconds after a Wi-Fi connect or disconnect event
              (Microsoft-Windows-WLAN-AutoConfig/Operational 8001 and 8003);
            - every -PollMinutes, as a backup check. Pulling the cable or
              unplugging a USB dock does not always log a network event,
              because the vEthernet adapter can stay up.
          A run that is triggered while another is in progress is skipped.
          Runs on battery. Stopped after 10 minutes.

      \WSL\Start Docker Desktop
          Starts Docker Desktop without elevation. It has no triggers; the
          main task starts it so that Docker Desktop never runs with admin
          rights.

    By default the main task starts powershell.exe through
    "conhost.exe --headless", which stops a console or Windows Terminal
    window flashing up on every run. Use -NoHeadlessConhost on Windows
    builds where that does not work.

    The install also checks that each switch in -SwitchPriority exists and is
    External, and that .wslconfig exists, and warns if not. These checks do
    not stop the install.

.PARAMETER SwitchPriority
    Names of the Hyper-V external switches to choose from, highest priority
    first. Passed to Update-WslSwitch.ps1 -SwitchPriority. A single comma-,
    semicolon- or space-separated string is also accepted.

    Default: ethbr0, wlanbr0

.PARAMETER InstallDir
    Folder that Update-WslSwitch.ps1 is copied into and run from. Created if
    missing. The copied script is unblocked (Unblock-File). This is also
    where Update-WslSwitch.ps1 writes its log by default.

    Default: $env:LOCALAPPDATA\WslSwitchSelector

.PARAMETER PollMinutes
    Minutes between backup checks by the main task. Each check that finds
    nothing to change is quick and makes no changes. Range 1 to 1440.

    Default: 5

.PARAMETER DockerDesktopExe
    Full path of Docker Desktop.exe. Used as the action of the
    "Start Docker Desktop" task, and passed to Update-WslSwitch.ps1 as a
    fallback.

    Default: $env:ProgramFiles\Docker\Docker\Docker Desktop.exe

.PARAMETER ExtraArguments
    Extra arguments added to the Update-WslSwitch.ps1 command line in the
    main task, as one string. Only switch parameters and simple values work
    here, because the script is started with powershell.exe -File.

    Example: '-IgnoreGateway -NoToast -CooldownSeconds 300'

.PARAMETER NoHeadlessConhost
    Start the main task with "powershell.exe -WindowStyle Hidden" instead of
    "conhost.exe --headless powershell.exe". A console window may flash up
    briefly on each run. Use this on Windows builds that do not support
    conhost --headless.

.PARAMETER RunNow
    Start the main task straight after installing it.

.PARAMETER Uninstall
    Remove both tasks instead of installing them. The installed script, the
    log and the cooldown state file in -InstallDir are left in place, and
    the .wslconfig file is not changed.

.INPUTS
    None. You cannot pipe objects to Install-WslSwitchTask.ps1.

.OUTPUTS
    None. Writes progress messages to the host.

.EXAMPLE
    PS> .\Install-WslSwitchTask.ps1 -RunNow

    Installs with the defaults (ethbr0, then wlanbr0, checking every 5
    minutes) and runs the main task straight away.

.EXAMPLE
    PS> .\Install-WslSwitchTask.ps1 -SwitchPriority ethbr0,wlanbr0 -PollMinutes 2

    Installs with a 2-minute backup check, so cable pulls are picked up
    sooner.

.EXAMPLE
    PS> .\Install-WslSwitchTask.ps1 -ExtraArguments '-NoToast -CooldownSeconds 300'

    Installs with notifications turned off and at most one change every
    5 minutes.

.EXAMPLE
    PS> .\Install-WslSwitchTask.ps1 -NoHeadlessConhost

    Installs using a hidden powershell.exe window instead of
    conhost --headless.

.EXAMPLE
    PS> .\Install-WslSwitchTask.ps1 -Uninstall

    Removes both scheduled tasks.

.EXAMPLE
    PS> Get-ScheduledTask -TaskPath '\WSL\' | Get-ScheduledTaskInfo

    Shows when each task last ran and its last result (0 means success).

.NOTES
    Requirements:
      - Windows PowerShell 5.1 or later, run as administrator.
      - Hyper-V PowerShell module (for the switch checks).
      - Update-WslSwitch.ps1 in the same folder as this script.

    To change the settings, run the installer again with new parameters; it
    replaces the existing tasks. To stop the automation without removing it,
    either disable "\WSL\Select Bridge Switch" in Task Scheduler or set
    networkingMode to something other than bridged in .wslconfig.

    The events and triggers can be checked in Task Scheduler under
    Task Scheduler Library > WSL.

.LINK
    Update-WslSwitch.ps1

.LINK
    https://learn.microsoft.com/windows/wsl/wsl-config

.LINK
    https://learn.microsoft.com/windows/win32/taskschd/task-scheduler-schema
#>
#Requires -Version 5.1
#Requires -RunAsAdministrator
[CmdletBinding()]
param(
    [string[]] $SwitchPriority = @('ethbr0', 'wlanbr0'),
    [string]   $InstallDir     = (Join-Path $env:LOCALAPPDATA 'WslSwitchSelector'),
    [ValidateRange(1, 1440)]
    [int]      $PollMinutes    = 5,
    [string]   $DockerDesktopExe = (Join-Path $env:ProgramFiles 'Docker\Docker\Docker Desktop.exe'),
    # Extra arguments passed through to Update-WslSwitch.ps1, e.g. '-IgnoreGateway -NoToast'
    [string]   $ExtraArguments = '',
    # Use powershell.exe -WindowStyle Hidden instead of conhost --headless (pre-Win11 22H2).
    [switch]   $NoHeadlessConhost,
    [switch]   $RunNow,
    [switch]   $Uninstall
)

$ErrorActionPreference = 'Stop'
$TaskPath   = '\WSL\'
$MainTask   = 'Select Bridge Switch'
$DockerTask = 'Start Docker Desktop'

if ($Uninstall) {
    foreach ($n in $MainTask, $DockerTask) {
        if (Get-ScheduledTask -TaskPath $TaskPath -TaskName $n -ErrorAction SilentlyContinue) {
            Unregister-ScheduledTask -TaskPath $TaskPath -TaskName $n -Confirm:$false
            Write-Host "Removed $TaskPath$n"
        }
    }
    Write-Host "Script and logs left in $InstallDir"
    return
}

$SwitchPriority = @($SwitchPriority | ForEach-Object { $_ -split '[,;\s]+' } | Where-Object { $_ })
$sid  = [Security.Principal.WindowsIdentity]::GetCurrent().User.Value
$esc  = { param($s) [Security.SecurityElement]::Escape($s) }

# Sanity checks
foreach ($s in $SwitchPriority) {
    $sw = Get-VMSwitch -Name $s -ErrorAction SilentlyContinue
    if (-not $sw) { Write-Warning "Switch '$s' does not exist (yet)." }
    elseif ($sw.SwitchType -ne 'External') { Write-Warning "Switch '$s' is $($sw.SwitchType), not External." }
}
if (-not (Test-Path -LiteralPath (Join-Path $env:USERPROFILE '.wslconfig'))) {
    Write-Warning "No .wslconfig in $env:USERPROFILE. Are you running elevated as a different account?"
}

# Copy the worker script
$src = Join-Path $PSScriptRoot 'Update-WslSwitch.ps1'
if (-not (Test-Path -LiteralPath $src)) { throw "Update-WslSwitch.ps1 not found next to this installer" }
New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
$dst = Join-Path $InstallDir 'Update-WslSwitch.ps1'
Copy-Item -LiteralPath $src -Destination $dst -Force
Unblock-File -LiteralPath $dst

# Build the action
$psArgs = "-NoProfile -NonInteractive -ExecutionPolicy Bypass -WindowStyle Hidden -File `"$dst`" -SwitchPriority $($SwitchPriority -join ',') -DockerDesktopExe `"$DockerDesktopExe`" $ExtraArguments".Trim()
if ($NoHeadlessConhost) {
    $cmd = 'powershell.exe'; $args_ = $psArgs
} else {
    # conhost --headless avoids a console (or Windows Terminal) window flashing up.
    $cmd = 'conhost.exe'; $args_ = "--headless powershell.exe $psArgs"
}

$query = @"
<QueryList>
  <Query Id="0" Path="Microsoft-Windows-NetworkProfile/Operational">
    <Select Path="Microsoft-Windows-NetworkProfile/Operational">*[System[(EventID=10000 or EventID=10001)]]</Select>
    <Select Path="Microsoft-Windows-WLAN-AutoConfig/Operational">*[System[(EventID=8001 or EventID=8003)]]</Select>
  </Query>
</QueryList>
"@

$start = (Get-Date).Date.ToString('yyyy-MM-ddTHH:mm:ss')

$mainXml = @"
<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.4" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Description>Selects the connected Hyper-V external switch for WSL2 bridged networking, updates .wslconfig and restarts WSL and Docker Desktop when it changes.</Description>
  </RegistrationInfo>
  <Triggers>
    <LogonTrigger>
      <Enabled>true</Enabled>
      <UserId>$sid</UserId>
      <Delay>PT45S</Delay>
    </LogonTrigger>
    <EventTrigger>
      <Enabled>true</Enabled>
      <Subscription>$(& $esc $query)</Subscription>
      <Delay>PT15S</Delay>
    </EventTrigger>
    <TimeTrigger>
      <Repetition>
        <Interval>PT$($PollMinutes)M</Interval>
        <StopAtDurationEnd>false</StopAtDurationEnd>
      </Repetition>
      <StartBoundary>$start</StartBoundary>
      <Enabled>true</Enabled>
    </TimeTrigger>
  </Triggers>
  <Principals>
    <Principal id="Author">
      <UserId>$sid</UserId>
      <LogonType>InteractiveToken</LogonType>
      <RunLevel>HighestAvailable</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>true</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <StopOnIdleEnd>false</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <WakeToRun>false</WakeToRun>
    <ExecutionTimeLimit>PT10M</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>$(& $esc $cmd)</Command>
      <Arguments>$(& $esc $args_)</Arguments>
    </Exec>
  </Actions>
</Task>
"@

$dockerXml = @"
<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.4" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Description>Launches Docker Desktop non-elevated. Called by \WSL\Select Bridge Switch.</Description>
  </RegistrationInfo>
  <Triggers />
  <Principals>
    <Principal id="Author">
      <UserId>$sid</UserId>
      <LogonType>InteractiveToken</LogonType>
      <RunLevel>LeastPrivilege</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <ExecutionTimeLimit>PT0S</ExecutionTimeLimit>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>$(& $esc $DockerDesktopExe)</Command>
    </Exec>
  </Actions>
</Task>
"@

Register-ScheduledTask -TaskPath $TaskPath -TaskName $DockerTask -Xml $dockerXml -Force | Out-Null
Write-Host "Registered $TaskPath$DockerTask"
Register-ScheduledTask -TaskPath $TaskPath -TaskName $MainTask -Xml $mainXml -Force | Out-Null
Write-Host "Registered $TaskPath$MainTask  (priority: $($SwitchPriority -join ' > '), poll every $PollMinutes min)"
Write-Host "Log: $(Join-Path $InstallDir 'WslSwitchSelector.log')"

if ($RunNow) {
    Start-ScheduledTask -TaskPath $TaskPath -TaskName $MainTask
    Write-Host 'Started. Check the log in a few seconds.'
}