Add-Member in PowerShell Workflow - powershell

Question

I have the following workflow in PowerShell:
workflow Audit-Computer
{
param([string[]]$Computers)
foreach -parallel ($computer in $Computers)
{
#Create a return object to hold the information we gather
$returnObject = [PSCustomObject]#{ComputerName=$computer}
#Test if the machine is reachable
$hostAlive = $true
try {
#Attempt a connection to the computer.
$os = Get-WmiObject –class Win32_OperatingSystem -PSComputerName $computer –erroraction Stop
#If we get here the connection was successful
$returnObject | Add-Member -MemberType NoteProperty -Name "HostAvailability" `
-Value "Online" -PassThru | `
Add-Member -MemberType NoteProperty -Name "OperatingSystem" -Value $os.Caption
} catch {
$hostAlive = $false
}
if($hostAlive){
#The host is alive lets run our audit
}
else
{
$returnObject | Add-Member -MemberType NoteProperty -Name "HostAvailability" -Value "Offline"
}
#Return the gathered information to the pipeline
Write-Output $returnObject
}
}
Unfortunately the Add-Member does not seem to work. The object returned does not contain the NoteProperties from add-member. How do I add properties to my custom object in a workflow?

Answer 1

There are several restrictions on cmdlets in PowerShell Workflows. According to this blog post, Add-Member is restricted to "local execution only".
I'm not able to test your script exactly, but this seemed to reproduce the same effect:
workflow Test-Workflow {
$obj = [PSCustomObject]#{ComputerName = 'test'}
$obj | Add-Member -MemberType NoteProperty -Name HostAvailable -Value "Online"
Write-Output $obj
}
but adding an InlineScript block made it work:
workflow Test-Workflow {
InlineScript {
$obj = [PSCustomObject]#{ComputerName = 'test'}
$obj | Add-Member -MemberType NoteProperty -Name HostAvailable -Value "Online"
Write-Output $obj
}
}