What is happening with these PSDriveInfo objects? - windows

Question

I have a few scripts that create multiple instances of PSDrive to remote instances. I want to make certain that each instance of PSDrive created is cleaned up.
I have a Powershell module like the following. This is a simplified version of what I actually run:
function Connect-PSDrive {
[CmdletBinding()]
param (
[Parameter(Mandatory=$true)]
$Root,
[String]
$Name = [Guid]::NewGuid().ToString(),
[ValidateSet("Registry","Alias","Environment","FileSystem","Function","Variable","Certificate","WSMan")]
[String]
$PSProvider = "FileSystem",
[Switch]
$Persist = $false,
[System.Management.Automation.PSCredential]
$Credential
)
$parameters = #{
Root = $Root;
Name = $Name;
PSProvider = $PSProvider;
Persist = $Persist;
}
$drive = $script:drives | Where-Object {
($_.Name -eq $Name) -or ($_.Root -eq $Root)
}
if (!$drive) {
if ($Credential) {
$parameters.Add("Credential", $Credential)
}
$script:drives += #(New-PSDrive #parameters)
if (Get-PSDrive | Where-Object { $_.Name -eq $Name }) {
Write-Host "The drive '$Name' was created successfully."
}
}
}
function Disconnect-PSDrives {
[CmdletBinding()]
param ()
$script:drives | Remove-PSDrive -Force
}
Each time I invoke the function Connect-PSDrive, I can see that a new drive is successfully created and a reference is added to $script:drives. At the end of the calling script, I have a finally block that invokes Disconnect-PSDrives and this fails with the following exception.
Remove-PSDrive : Cannot find drive. A drive with the name 'mydrive' does not exist.
At C:\git\ops\release-scripts\PSModules\PSDriveWrapper\PSDriveWrapper.psm1:132 char:22
+ $script:drives | Remove-PSDrive -Force
+ ~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (mydrive:String) [Remove-PSDrive], DriveNotFoundException
+ FullyQualifiedErrorId : DriveNotFound,Microsoft.PowerShell.Commands.RemovePSDriveCommand
I want to know why references to the PSDrive objects I created are available in $script:drives, and yet Remove-PSDrive fails to locate the objects.
I also want to know how I can manage these PSDrive instances without needing to return each instance to the calling script such that Disconnect-PSDrives works.
A few extra notes:
I'm creating these drives with the Persist flag as false.
Running these multiple times errors with too many multiple connections being made to a machine. This is why I think that connections are not being cleaned up. If my assumption is wrong, please kindly explain why connections are cleaned up.

Answer 1

I am a little surprised that it cannot remove from the object reference; but I assume that your issue is with scope. PSDrives are local scope by default so when your function exits, they are no longer visible. Use the -Scope parameter for New-PSDrive and you will likely be successful. (As a side note: during Disconnect-PSDrives you will likely want to clear the list in case of multiple calls.)
That being said, you should never need to clean up the PSDrives like you are doing. Likely the reason you are experiencing too many connections is, once again, a scoping issue (that is, they still exist but you no longer see them). Try running it multiple times where you close PowerShell and start a new instance each time--you will no longer see too many connections. Why? Because PowerShell cleans up all non-persistent drives at the end of your session. You do not need to clean up the drives between sessions/instances; and within an session/instance (assuming you have proper scoping) you can re-use the drives so there is no need to create duplicates; ergo, you should never really need this functionality. That being said, I might assume you have some niche use case for this?