Powershell: Imported modules that were exported seem to be broken

[rfoust]

Exporting a module locally (such as Office 365 remote powershell) and then re-importing it results in the cmdlets in that module being broken (on Mac/Linux, haven't tested Windows). The error they return is below. If I just connect to the Office 365 powershell session directly without exporting it, it works fine. So it seems to be something with the re-imported module that breaks it?

Steps to reproduce

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri "https://outlook.office365.com/powershell-liveid/" -Credential (Get-Credential) -Authentication Basic -AllowRedirection -Name TestTenant
Export-PSSession $Session -OutputModule "path_to_module" -AllowClobber
Import-Module TestTenant -DisableNameChecking -Global

Expected behavior

The imported module should work.

Actual behavior

PS /Users/rfoust> Get-Mailbox
Creating a new session for implicit remoting of "Get-Mailbox" command...
Exception calling "GetSteppablePipeline" with "1" argument(s): "The expression after '&' in
a pipeline element produced an object that was not valid. It must result in a command name, a script
block, or a CommandInfo object."
At /Users/rfoust/.local/share/powershell/Modules/TestTenant/TestTenant.psm1:18294 char:13
+             $steppablePipeline = $scriptCmd.GetSteppablePipeline($myI ...
+             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : CmdletInvocationException

Environment data

Name                           Value
----                           -----
PSVersion                      6.1.2
PSEdition                      Core
GitCommitId                    6.1.2
OS                             Darwin 18.2.0 Darwin Kernel Version 18.2.0: Thu Dec 20 20:46:53 PST 2018; root:xnu-4903.241.1~1/RELEASE_X86_64
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[kilasuit]

I believe you need to do the below get them imported properly (or at least I have has this in one of my scripts for a long long time as part of an older office 365 connection script that I had as part of a module that for that imported in my profile)

#Connect-EXOSession#
Function Connect-EXOSession {
<#
.Synopsis
   Short description
.DESCRIPTION
   Long description
.EXAMPLE
   Example of how to use this cmdlet
.EXAMPLE
   Another example of how to use this cmdlet
#>
param (
    [Parameter(Mandatory=$true)][PSCredential]$EXOCredential

     )
$Global:Session = New-PSSession -ConfigurationName Microsoft.Exchange `
                    -ConnectionUri https://ps.outlook.com/powershell/ `
                    -Credential $EXOCredential -Authentication Basic `
                    -AllowRedirection -Name EXOSession -WarningAction SilentlyContinue 
Import-Module (Import-PSSession -Session $Global:Session -Verbose:$false -DisableNameChecking -AllowClobber) -Global -DisableNameChecking
}

I then called these lines in my profile

Function Connect-MyEXOSession { 
Import-Module GitHub:\kilasuit\PoshFunctions\Modules\Connect-EXOSession\Connect-EXOSession.psd1 ; 
$MYO365cred = Get-bCredential -Credential MyO365UserName -Store # as using BetterCredentials Module
Connect-EXOSession -EXOCredential $MYO365cred
}

Connect-MyEXOSession 

[rfoust]

Thanks @kilasuit for the suggestion. Yes, I am able to get it to work if I don't export the module. But what I do on regular Windows Powershell is export the module so that I can update the line in the .psm1 file that asks for credentials to use a global variable that already has the credential. This way, the module with automatically re-authenticate without prompting when the session dies. I'm trying to replicate that behavior in PS Core.

[rfoust]

This is the line in the .psm1 that is triggering the exception. $myInvocation.CommandOrigin is "Runspace".

$steppablePipeline = $scriptCmd.GetSteppablePipeline($myInvocation.CommandOrigin)

[vexx32]

@rfoust I don't know enough an the technical side in this case to know why that regression exists, but in the meantime you can apply such a modification on the in-memory module, and then remove and reload it.

[rfoust]

@vexx32 Interesting idea, I didn't realize it was possible to modify an in-memory module. Can you elaborate on how I would do that or point me in the right direction? Thanks!

[vexx32]

The basic method I'd probably tackle it from is like this:

# usually these are temp_* for an imported PSSession
$Module = Get-Module -Name $ModuleName 

# single-quotes! Variable names need to be intact
$ModuleScript = [scriptblock]::Create($Module.Definition -replace '<credential_line>','$global:Creds') 

# Create new module from modified script block
$New = New-Module -Name NewModuleName -ScriptBlock $ModuleScript

# remove original copy of the module from the session
Remove-Module $Module.Name 

# import the new module
$New | Import-Module 

This might run into the same issue, but... it's worth a shot nonetheless. 😄

[rfoust]

@vexx32 Oh wow, doing it that way never occurred to me. Mind blown. :) It worked on a quick test! I still need to put that logic in my wrapper function and see how it behaves after the session breaks. But looks promising so far, thanks!

[vexx32]

It'd be really cool if doing the Export-PSSession how you were handling it supported a -Credential parameter so you could just pass them in and have it work, but that's probably a separate issue/request.

Let me know how you get on, I'm curious to see if it behaves as expected. 😄

[rfoust]

@vexx32 So when I remove the existing pssession, I get the same error. So this caused me to do a little more tracing and long story short, the original problem I have is being caused because New-PSSessionOption does not exist in PS Core (on mac/linux?). Not sure why.

But anyway, since that cmdlet doesn't exist, it is causing the New-PSSession command to bomb out somewhere when it is called this way in the .psm1 file:

Set-PSImplicitRemotingSession `
            -CreatedByModule $true `
            -PSSession (
                $(
                & $script:NewPSSession `
                    -connectionUri 'https://outlook.office365.com/powershell-liveid/' -ConfigurationName 'Microsoft.Exchange' `
                    -SessionOption (Get-PSImplicitRemotingSessionOption) `
                    -Credential ( $host.UI.PromptForCredential( 'PowerShell Credential Request', 'Enter your credentials for https://outlook.office365.com/powershell-liveid/.', '[email protected]', 'outlook.office365.com' ) ) `
                     `
                    -Authentication Basic `
                    -AllowRedirection `
                    -Verbose `
                )
            )

Specifically, the -SessionOption line is where it dies. So if I go back to my original code, I can just strip out that line to resolve all my problems.

But I guess this bug still technically exists, and the question is why is that cmdlet not there? According to the docs, it should be:

https://docs.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Core/New-PSSessionOption?view=powershell-6

[rfoust]

Also just for anyone reading along, to save ya some time, the -SessionOption parameter calls Get-PSImplicitRemotingSessionOption which is this:

function Get-PSImplicitRemotingSessionOption
{
    if ($null -ne $PSSessionOptionOverride)
    {
        return $PSSessionOptionOverride
    }
    else
    {
        return $(& $script:NewPSSessionOption -Culture 'en-US' -UICulture 'en-US' -CancelTimeOut 60000 -IdleTimeOut -1 -OpenTimeOut 180000 -OperationTimeOut 180000 -MaximumReceivedObjectSize 209715200 -MaximumRedirection 5 -ProxyAccessType None -ProxyAuthentication Negotiate )
    }
}

and $script:NewPSSessionOption is this:

$script:NewPSSessionOption = $executionContext.InvokeCommand.GetCommand('New-PSSessionOption', [System.Management.Automation.CommandTypes]::Cmdlet)

This is all auto-generated when the module is exported.