Modify Active Directory Client OU from Client Machine - powershell

Question

I am trying to create a powershell startup script for my domain controlled computers that will place the computer into the the specified OU. I would like for the variables to be taken on the local computer and then passed to the remote server. Once there I would like to execute the last two lines on the server.
The script below does work if it is ran on the server however as stated above I would like to be able to execute this from a client machine. How can I make this happen?
$computername = $env:ComputerName
$new_ou = "OU=TestOU,DC=Test,DC=Controller,DC=com"
Import-Module ActiveDirectory
Get-ADComputer $computername | Move-ADObject -TargetPath $new_ou
Note: Before anyone asks...my goal is to have the OU be determined by the client IP address. I understand that there are scripts that will do the discribed above but they run strictly on the server and query the DNS. I would rather have this run as a startup script on the local computer so I an better control which computers are being moved. At this point I am not interested in tackling this issue. Only the issue of how to execute the above lines on a local machine.

Answer 1

I assume you want to run the last 2 lines on the server because you expect that most of your domain computers won't have the RSAT tools or AD cmdlets installed.
The way to run it on a server is to have PowerShell Remoting enabled on the server and then use Invoke-Command.
That authentication is typically done with kerberos, though you could change the method, and you can supply credentials manually (though I doubt you want to be embedding credentials in the script).
You need to consider that the user making the AD changes needs permission to do so. Usually that's a domain admin, although permission could be delegated.
If you're running this as a startup script, it's running as SYSTEM. That account authenticates on the domain as the computer account (COMPUTERNAME$). This means that the computer account needs permission to move itself, which may mean it needs the ability to write objects into all possible OUs (I don't recall offhand which permissions are needed).
So you would either need to grant this ability to all computers (any computer in Domain Computers would have the ability to move any other computer to any OU), or somehow give each computer only the ability to move itself into the correct OU (which might still be too much in the way of permissions).
Another option is to make a customized session configuration on the server with a RunAs user. You could limit the users allowed to connect to the session (to Domain Computers), and limit the allowed commands so that the connecting computers can only run a limited set of functions/cmdlets. Even better, you can write your own function to do the change and only let them run that one. With the RunAs user being a privileged user in AD, the changes will work without the connecting user having the ability to make the changes directly, and without giving the connecting user the ability to use the privileged user or elevate their own permission. Remember that the connecting user in this case is the computer account.
This last method is, I think, the best/most secure way to do what you want, if you insist that it must be initiated from the client machine.
Reconsider doing this as a server-side process. Get-ADComputer can return an IPv4 address for the object, so you could use that instead of DNS. Centralizing it would make it easier to manage and troubleshoot the process.