Invoke-Command in Workflow sequence - powershell

Question

Please help to get Invoke-Command working. It says -ScriptBlock parameter is null. It seems RegHomePage() function is not available in InlineScript{}.
function RegHomePage (){
get-item -path Registry::"HKEY_USERS\*\Software\Microsoft\Internet Explorer\Main" | `
Get-ItemProperty | Where-Object {$_."Start Page" -ne $null} | Set-ItemProperty -Name "Start Page" -Value "about:blank"
}
$creds = Get-Credential -Credential value\wadmin
workflow foreachtest
{
param([Parameter(mandatory=$true)][string[]]$computers)
foreach -parallel -throttlelimit 20 ($computer in $computers)
{
sequence
{
$isPing = Test-Connection -count 1 $computer -quiet
if($isPing){
$isWSMan = [bool](Test-WSMan $computer -ErrorAction SilentlyContinue)
}
if($isWSMan){
InlineScript{
Invoke-Command -ComputerName $USING:computer -ScriptBlock ${function:RegHomePage}
} -PSComputerName $computer
echo "$computer OK"
}
Else{
$Workflow:out += "$computer`r`n"
echo "$computer FAILED"
}
}
}
Out-File .\offline.txt -InputObject $out
}
foreachtest -computers (Get-Content .\comps.txt)

Answer 1

Seems to have a few issues with this inlineScript block.
Dont provide the PSComputerName parameter since you are already running a job on each computer. There is no need to reference other systems here.
I would suggest using Write-Output instead of echo (use powershell native commands)
Move the function within the inlinescript to bring it in scope of each iteration.
workflow testing {
foreach -parallel ($computer in $computers) {
sequence {
inlinescript {
function RegHomePage {
Get-Item -path Registry::"HKEY_USERS\*\Software\Microsoft\Internet Explorer\Main" | `
Get-ItemProperty | Where-Object {$_."Start Page" -ne $null} | Set-ItemProperty -Name "Start Page" -Value "about:blank"
}
Invoke-Command -ComputerName $using:computer -ScriptBlock ${Function:RegHomePage}
}
}
}
}
Following is what I tested with.
workflow testingWF {
Param ([string[]] $computers)
foreach -parallel ($computer in $computers) {
sequence {
InlineScript {
function testFunc {
Param($comp)
Write-Output "$($comp.split('.')[0]) == TestFunc"
}
Invoke-Command -ComputerName $Using:computer -ScriptBlock ${Function:testFunc} -ArgumentList $using:computer
}
}
}
}
testingWF serverFQDN1,serverFQDN2
#Prints
server1 == TestFunc
server2 == TestFunc
Suggestion on how to re-write the above code
Instead of using a workflow to run a parallel foreach loop, i would recommend replacing the functionality with -AsJob.
foreach($computer in $computers) {
Invoke-Command -ComputerName $computer -ScriptBlock ${Function:RegHomePage} -AsJob
}
# Remove Jobs when done
Get-Job | Wait-Job | Remove-Job

Answer 2

InlineScript dont support $using:function , try nested workflow nested work
You can move your function inside InlineScript block .
Are you sure that key -PSComputerName must have value $Computers instead $computer
Adding
Only one way to call function at inlinescriptblock, it's a put it inside. But may you can use nested workflow to call few times invoke comand. Example nested:
workflow Test-Workflow {
function mess{"get ready"}
workflow nest-test{
mess
}
nest-test
}
Test-Workflow
You can also read why you can't use import it to inline script in this tutorial:
tutorial