How to get Invoke-Command verbose or debug output from a PowerShell command in C#

Question

I have a PowerShell command that invokes a command on a remote machine to print out a debug message, and then prints out a debug message on the running machine, as follows:

function Start-DebugTest {
    [cmdletbinding()]
    param ()

    $cmd = {
        $DebugPreference = 'Continue'
        Write-Debug -Message 'This is invoked DEBUG message'
    }

    $params = @{
        ComputerName = $ip
        Credential = $cred
        ScriptBlock = $cmd
    }

    Invoke-Command @params

    Write-Debug -Message 'This is a normal DEBUG message'
}

When I run the Start-DebugTest command locally I see the following output:

DEBUG: This is invoked DEBUG message
DEBUG: This is a normal DEBUG message

When I run this through C# like this:

using (PowerShell powershell = PowerShell.Create())
{
    var command = powershell.AddCommand("Start-DebugTest");
    powershell.Runspace.SessionStateProxy.SetVariable("DebugPreference", "Continue");

    PSDataCollection<PSObject> output = new PSDataCollection<PSObject>();
            output.DataAdded += (sender, args) => DataAdded((PSDataCollection<PSObject>) sender, progress);
    powershell.Streams.Debug.DataAdded += (sender, args) => StreamDataAdded((PSDataCollection<DebugRecord>) sender, args, "DEBUG", progress);

    var resources = await Task.Factory.FromAsync(
         powershell.BeginInvoke<PSObject, PSObject>(null, output),
         asyncResult => powershell.EndInvoke(asyncResult));

    return resources;
}

private void StreamDataAdded<T>(PSDataCollection<T> records, DataAddedEventArgs e, string msgType, IProgress<string> progress) where T : InformationalRecord
{
    string msg = records[e.Index].Message;
    progress.Report($"{msgType}: {msg}");
}

private void DataAdded(PSDataCollection<PSObject> myp, IProgress<string> progress)
{
    Collection<PSObject> results = myp.ReadAll();
    foreach (PSObject result in results)
    {
        progress.Report($"OUTPUT: {result.ToString()}");
    }
}

I only receive the debug message running on the local machine and not the one from the invoked command, from either of the DataAdded events:

DEBUG: This is a normal DEBUG message

If I see the output when running it locally, somehow the debug message is available. Is there any way to access it from C#?

The problem is the example isn't ready to test. – fdafadf Feb 21 '18 at 09:20 — fdafadf, Feb 21 '18 at 09:20

score 0 · Answer 1 · answered Feb 21 '18 at 08:52

I reckon you probably have to specify your debug preference on the Invoke-Command call...

about_Preference_Variables

The preference variables affect the PowerShell operating environment and all commands run in the environment.

The key point here is "in the environment"

The command running on the other environment doesn't share the same preference setting as the calling command.

about_CommonParameters

-Debug[:{$true | $false}]

Displays programmer-level detail about the operation performed by the command. This parameter works only when the command generates a debugging message. For example, this parameter works when a command contains the Write-Debug cmdlet.

Solution

$params = @{
    ComputerName = $ip
    Credential = $cred
    ScriptBlock = $cmd
    Debug = $true
}

Invoke-Command @params

How to get Invoke-Command verbose or debug output from a PowerShell command in C#

1 Answers1

about_Preference_Variables

about_CommonParameters

Solution