Question

I need to be able to execute a PS1 script that resides on a remote machine against another remote machine through a C# runspace.

To be clear what I mean by this: The service I’m creating resides on server A. It creates a remote runspace to server B using the method below. Through the runspace I’m trying to call a script residing on server C against server B. If it helps, currently server A IS server C, but it’s not guaranteed that will always be the case.

Here’s the method I’m using to make the remote call:

internal Collection<PSObject> RunRemoteScript(string remoteScript, string remoteServer, string scriptName, out bool scriptSuccessful)
    {
        bool isLocal = (remoteServer == "localhost" || remoteServer == "127.0.0.1" || remoteServer == Environment.MachineName);

        WSManConnectionInfo connectionInfo = null;

        if (!isLocal)
        {
            connectionInfo = new WSManConnectionInfo(new Uri("http://" + remoteServer + ":5985"));
        }

        PsHostImplementation myHost = new PsHostImplementation(scriptName);

        using (Runspace remoteRunspace = (isLocal ? RunspaceFactory.CreateRunspace(myHost) : RunspaceFactory.CreateRunspace(myHost, connectionInfo)))
        {
            remoteRunspace.Open();
            using (PowerShell powershell = PowerShell.Create())
            {
                powershell.Runspace = remoteRunspace;

                Pipeline pipeline = remoteRunspace.CreatePipeline();

                pipeline.Commands.AddScript(remoteScript);

                Collection<PSObject> results = pipeline.Invoke();

                remoteRunspace.Close();

                scriptSuccessful = myHost.ScriptSuccessful;
                return results;
            }
        }
    }

“remoteScript” is set to the Powershell script I want to run. For example:

"& \"\\\\remoteserveraddress\\PathToScript\\Install.ps1\" -Parameter;Import-Module Modulename;CustomCommand-FromModule -parameter(s) -ErrorAction stop"

If I’m on the remote machine that I want to run the script on, in the powershell console I can just give the following command:

& "\\remoteserverC\PathToScript\Install.ps1" -Parameter

However this simply refuses to work for me if I try to run it through the c# runspace.

If I send in the following as a parameter to “remoteScript”:

"& \"\\\\remoteserverC\\PathToScript\\Install.ps1\" -Parameter"

I get the following error:

The term ‘\remoteserverC\PathToScript\Install.ps1’ is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.

I’ve tried with and without ‘&’ and with and without the parameter. I can already call a script that resides directly on the remote machine “c:\…\Install.ps1” instead of “\\remoteserver\…\Install.ps1”, but it would be greatly beneficial to be able to call the remote script directly.

I’ve searched many many pages in google and here on stackoverflow, but I haven’t been able to find anything that helps to overcome this issue. Any help would be appreciated! Thanks!

Answer 1

I never did get this to work directly and seems to be a security “feature” that you can’t access a third machine using a UNC address while working remotely. I was however able to find a workaround that worked great for me.

Instead of trying to call directly to a \\server\share address, I dynamically map a network drive on the machine I’m trying to run the script against to a share on the machine that has the script. (Running remotely from A, map a drive on B to a share on C). Then I call my scripts through that drive and it works like a charm. This string is what I pass in to the RunRemoteScript method above:

"$net = new-object -ComObject WScript.Network;" +
"if(!($net.EnumNetworkDrives() -contains \"S:\"))" +
    "{Write-Host \"S: Drive Not Currently Mapped. Mapping to \\\\" + RemoteServerC + "\\Share.\";" +
    "$net.MapNetWorkDrive(\"S:\",\"\\\\" + RemoteServerC + "\\Share\",$false,\"username\",\"password\")};" +
"Get-PSDrive | Write-Verbose;" +
"& \"S:\\PathToScript\\Install.ps1\" -noPrompt;"

RemoteServerC is a variable I pass in that is defined in a user config file.

Here is the same code as just powershell script if anyone needs it (replacing RemoteServerC with a powershell variable you’d need to set before or just hardcode:

$net = new-object -ComObject WScript.Network
if(!($net.EnumNetworkDrives() -contains "S:"))
{  Write-Host "S: Drive Not Currently Mapped. Mapping to \\remoteserverC\Share."
   $net.MapNetWorkDrive("S:","\\remoteserverC\Share",$false,"username","password")
}
Get-PSDrive | Write-Verbose
& "S:\\PathToScript\\Install.ps1\" -noPrompt;"

First I set up the object to be able to map the drive. I then check if there is already an “s” drive mapped on the remote machine. If it hasn’t I then map the share to the “s” drive on the remote machine using a name and password we set up in active directory to run this service.

I included the Get-PSDrive command because it appears to force powershell to reload the list of available drives. This seems to only matter the very first time you try to run this in a powershell session (and through c sharp I don’t know if it is truly necessary or not, I included it to be safe). Apparently powershell does not recognize a drive addition in the same session it was created if you use MapNetworkDrive.