How to use Jenkins pipeline method parameters in Powershell script?

[Daniel Christian Schröter]

I ask this question already on https://stackoverflow.com/questions/51622150/how-to-use-jenkins-pipeline-method-parameters-in-powershell-script, but maybe here is someone to help me.

I defined the following method in jenkins declarative pipeline, but I am not able to use the variables/output from "serverName", "archiveDestination" and "wwwrootPath". I tried already different ways but is does not work. The output from Write-Output is still "$serverName", ${archiveDestination} and/or an empty variable.

How can I access the parameters from the serverdeployment-method in the Powershell script part?

def serverdeployment(serverName, archiveDestination, wwwrootPath) {
    powershell script: '''
    $servername = \'"$serverName"'
    $archivedestination = \'${archiveDestination}'
    $wwwrootpath = ${wwwrootPath}
    Write-Output $servername
    Write-Output $archivedestination
    Write-Output $wwwrootpath
    $pass = ConvertTo-SecureString -AsPlainText "XXXXX" -Force
    $cred = New-Object System.Management.Automation.PSCredential -ArgumentList "XXXXX",$pass
    $sessionOption = New-PSSessionOption -SkipCACheck -SkipCNCheck -SkipRevocationCheck
    $session = New-PSSession -ComputerName $serverName -UseSSL -Credential $cred -SessionOption $sessionOption
    Copy-Item $env:WORKSPACE\\* -Destination "$archiveDestination" -Filter *TEST* -Recurse -Force -Verbose -ToSession $session
    Invoke-Command -Session $session -ScriptBlock {iisreset /STOP}
    $filename = $env:JOB_NAME + "_TEST_" + $env:Version + "_" + $env:BUILD_NUMBER + "_wwwroot.7z"
    Invoke-Command -Session $session -ScriptBlock { & "C:\\Program Files\\7-Zip\\7z.exe" x $using:archiveDestination$using:filename -o$wwwrootpath -aoa >$null }
    Remove-Item "$wwwrootPath\\*\\_Cache\\*" -Recurse -Force
    Invoke-Command -Session $session -ScriptBlock {iisreset /START}
    Remove-PSSession $session
    Exit-PSSession
    '''
}

This method will be executed in steps part:

serverdeployment('myservername', 'C:\\data\\install\\', 'C:\\inetpub\\wwwroot\\')

Thank you!