Passing arguments to Powershell script - powershell

Question

I have a script that takes in a max of 3 parameters - username, password and distro.
The script needs to run as administrator since it checks certain things are enabled and can only be done as an admin.
# the command line is:
# linux-docker <username> <password> <distro>
# if no distro is specified then Debian is used.
param ([Parameter(Mandatory)]$username, [Parameter(Mandatory)]$password, $distro='Debian')
# check if we are in admin mode and switch if we aren't
$currentPrincipal = New-Object Security.Principal.WindowsPrincipal([Security.Principal.WindowsIdentity]::GetCurrent())
if (-Not $currentPrincipal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
if (!([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")) {
Start-Process powershell.exe "-NoProfile -ExecutionPolicy Bypass -File `"$PSCommandPath`"" -Verb RunAs;
Read-Host -Prompt "Failure: Press Enter to exit"
exit;
}
}
# ... rest of script
However restarting the script prompts the user for username and password. I would like to pass the arguments to the promoted script.
I first thought that adding $username,$password and $distro to the Start-Process command.
Start-Process powershell.exe "-NoProfile -ExecutionPolicy Bypass -File `"$PSCommandPath`" $username $password $debian" -Verb RunAs;
but that exits with the "Failure" message.
So I looked at -ArgumentList but that dies processing that line:
Start-Process : A positional parameter cannot be found that accepts argument '-NoProfile -ExecutionPolicy Bypass -File "C:\Users\Graham Reeds\Documents\linux-docker.ps1"'.
At C:\Users\Graham Reeds\Documents\linux-docker.ps1:15 char:9
+ Start-Process powershell.exe "-NoProfile -ExecutionPolicy Byp ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Start-Process], ParameterBindingException
+ FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.StartProcessCommand
Failure: Press Enter to exit:
It is probably something simple but I am a noob with Powershell.

Answer 1

Using the -ArgumentList parameter should work, but for the parameters sent to the script, you need to
get their names and values from the BoundParameters hash:
$currentPrincipal = [Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()
$isAdmin = $currentPrincipal.IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
if (!$isAdmin) {
$argList = '-NoLogo', '-NoProfile', '-NoExit', '-ExecutionPolicy Bypass', '-File', ('"{0}"' -f $PSCommandPath)
# Add script arguments
$argList += $MyInvocation.BoundParameters.GetEnumerator() | ForEach-Object {"-$($_.Key)", "$($_.Value)"}
try {
Start-Process PowerShell.exe -WorkingDirectory $pwd.ProviderPath -ArgumentList $argList -Verb Runas -ErrorAction Stop
# exit the current script
exit
}
catch {
Write-Warning "Failed to restart script '$PSCommandPath' with runas"
}
}
# rest of the script
P.S. Personally I like to always type-cast parameters and when possible make it clear in what order the mandatory parameters should be given if not used Named:
param (
[Parameter(Mandatory = $true, Position = 0)][string] $username,
[Parameter(Mandatory = $true, Position = 1)][string] $password,
[string] $distro='Debian'
)