How to get local computer name after New-PSSession -Computername? - powershell

Question

I am getting the below error, please advise how to fix this error for null-valued expression
You cannnot call a method on a null-valued expression
+CategoryInfo : InvalidOoperation: (:)[], RuntimeException
+FullyQualifiedErrorId: InvokeMethodonNull
+PSComputerName: DC1
Code below
function myfunction (){
$remoteserver = 'DC1'
$Session = New-PSSession -Computername $remoteserver -Credential $Cred
Import-Module ActiveDirectory
$local= $env:COMPUTERNAME
Invoke-Command -ComputerName $remoteserver -Credential $cred -ScriptBlock
{$using:local
if($local.substring(5,3) -imatch "Sys") {
Get-ADComputer $local | Move-ADObject -Targetpath "ou=PRD,ou=Servers,dc=com,dc=Companycorp,dc=net"}
}
} #end function
Invoke-Command -ComputerName $remoteserver -ScriptBlock ${Function:myFunction}

Answer 1

What you're looking for is the $using: scope. If you define variables that you want to use in your remote execution, you need to access them like:
$PC = $env:ComputerName
Invoke-Command -Computer DC01 -ScriptBlock { $using:PC <# logic #> }
If you mean you want to remote into DC01 to run commands against localhost, you're going to run into the second-hop problem due to Kerberos.
Update: Your new example looks pretty convoluted. Here's an example that should work:
$MyPC = $env:ComputerName
$Session = New-PSSession -Credential (Get-Credential) -ComputerName 'DC1'
Invoke-Command -Session $Session -ScriptBlock {
Import-Module -Name 'ActiveDirectory'
$PC = $using:MyPC
If ($PC.Substring(5,3) -eq 'sys')
{
Get-ADComputer -Identity $PC |
Move-ADObject -TargetPath 'ou=PRD,ou=Servers,dc=com,dc=Companycorp,dc=net'
}
}

Answer 2

What I think you're asking is 'how do I open a session on a remote pc, but then still run commands on my local PC'. If that's so, then let's walk through it.
First, we can open a remote connection to another computer in PowerShell by creating a new PSSession, as you're doing here:
$session = New-PSSession -Computername DC01 -Credential $cred
You can then either step into the remote computer wholly using Enter-PSSession, or just send individual commands to the remote computer using:
Invoke-Command -ScriptBlock {#Commands to run on the remote PC}`
-Session $session
Once you enter the remote PC, you can return to your own PC using the Exit-PSSession command.
#Enter Remote PC
Enter-PSSession $session
DC01> hostname
*DC01*
#Step out of Remote PC
Exit-PSSession
PS> hostname
*YOURPCNAME*
If this isn't what you want to do, let me know and we'll get you sorted.

Answer 3

You have to use Invoke-Command :
$session = New-PSSession -Computername DC01 -Credential $cred
Invoke-Command -Session $session -ScriptBlock {
$remoteComputerName = $env:computername
}