Pass array of CimInstance to CimMethod - powershell

Question

I am working with WMI API through Cim cmdlets. The problem is that I can't figure out how to pass wmi object to wmi method that accepts array of wmi objects.
Here are method parameters definition:
Name CimType Qualifiers
---- ------- ----------
Path String {ID, in}
Permissions InstanceArray {EmbeddedInstance, ID, in}
ResetChildren Boolean {ID, in}
Path and ResetChildren are simple parameters. They accepts simple values like "/path" and $true respectively. But I have troubles with Permissions parameter.
Here is my code
#Acquiring object that I want to pass to method
$group = Get-CimInstance -Namespace "root\VisualSVN" -ClassName VisualSVN_Group -Filter "Name='Readers'"
#Acquiring object which method will be called
$repositories = Get-CimInstance -Namespace "root\VisualSVN" -ClassName VisualSVN_Repository
#Preparing method arguments
$args = #{
Path = "/";
Permissions = #($group[0]); #Trouble here
ResetChildren = $true
}
#Invoking method with arguments
Invoke-CimMethod -InputObject ($repositories[0]) -MethodName SetSecurity -Arguments $args
Execution of this code will result in error:
Invoke-CimMethod : Unable to cast object of type 'Microsoft.Management.Infrastructure.CimInstance' to type 'M
icrosoft.Management.Infrastructure.Native.InstanceHandle'.
Parameter name: value
At C:\somepath\script1.ps1:11 char:1
+ Invoke-CimMethod -InputObject ($repositories[0]) -MethodName SetSecurity -Argume ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Invoke-CimMethod], ArgumentException
+ FullyQualifiedErrorId : System.ArgumentException,Microsoft.Management.Infrastructure.CimCmdlets.Invoke
CimMethodCommand
If you change code
Permissions = #($group[0]); #Trouble here
To code
Permissions = $group; #Trouble here
Then error message will also change:
Invoke-CimMethod : Unable to cast object of type 'Microsoft.Management.Infrastructure.Native.InstanceHandle'
to type 'System.Collections.IList'.
Parameter name: value
At C:\somepath\script1.ps1:11 char:1
+ Invoke-CimMethod -InputObject ($repositories[0]) -MethodName SetSecurity -Argume ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Invoke-CimMethod], ArgumentException
+ FullyQualifiedErrorId : System.ArgumentException,Microsoft.Management.Infrastructure.CimCmdlets.Invoke
CimMethodCommand
Any ideas how to pass $group to method properly?

Answer 1

I had exactly same problem with VisualSVN_Repository::SetSecurity method.
When working with CIM method arguments, you must cast ANY array arguments to [CimInstance[]].
For example, this worked for me:
$Everyone = Get-CimInstance -Namespace root/VisualSVN -ClassName VisualSVN_Everyone
# Grant Everyone a Read/Write access:
$AccessRule = New-CimInstance -Namespace root/VisualSVN -ClassName VisualSVN_PermissionEntry -ClientOnly -Property #{ Account = $Everyone; AccessLevel = [UInt32]2 }
$SvnRepo = Get-CimInstance -Namespace root/VisualSVN -ClassName VisualSVN_Repository -Filter "Name='MY_REPOSITORY_NAME'"
Invoke-CimMethod -InputObject $SvnRepo -MethodName SetSecurity -Arguments #{
Path = '/';
Permissions = [CimInstance[]]$AccessRule;
ResetChildren = $true
} | Out-Null
You must cast array argument to [CimInstance[]] even when it is just a single item.
P.S.: Be careful with Ref array arguments too: you must first cast it to [CimInstance[]] and then to [ref[]]. For example, when calling VisualSVN_Group::Create method:
[CimInstance[]] $SvnUsers = [CimInstance[]]($ArrayOf_VisualSVN_User_Objects)
Invoke-CimMethod -ClassName VisualSVN_Group -Namespace root/VisualSVN -MethodName Create -Arguments #{
Members = [ref[]]$SvnUsers;
Name = 'MY_NEW_GROUP_NAME'
} | Out-Null
See also: Tip#5: Passing ref and embedded instances on PowerShell Blog.

Answer 2

If you had a repro that did not rely on software I do not have installed, I could answer definitively, so I will make my best attempt based on what I can infer from your question.
To make what you are assigning to Permissions an array, and you are only assigning one value, use a comma in front.
Permissions = ,$group
Here is some sample script and the output to demonstrate.
Script
$var1 = "any value"
$var2 = ,$var1
$var1.GetType()
$var2.GetType()
$var2.Count
$var2[0]
Output
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True String System.Object
True True Object[] System.Array
1
any value

Answer 3

A possible solution (it worked for me with a similar issue that led me here) based on the 'hint' that CIM are inert objects. In my case it was installing SCCM updates in a scripted manner while allowing for reboots if the updates required them, and stopping if the entire process took more than a certain amount of time (to not go past the available maintenance window).
I was passing a CIMUpdate object through to a powershell function to perform the update to allow for rebooting if necessary between updates (Perform a single update at a time, verify if reboot is needed, then try the next update).
The CIM object was giving a Type Mismatch error when forcing it to cast as [CIMInstance[]], and if not casting at all I would get the same Unable to cast object of type 'Microsoft.Management.Infrastructure.CimInstance' to type 'Microsoft.Management.Infrastructure.Native.InstanceHandle' error message.
Solution was to use that CIMUpdate and re-query to get a live version of the object within the function and then use that new object as the argument to the CIMMethod.

Answer 4

as of now, it works for me , the case I am working on is passing New-ScheduledTaskTrigger instance to a function.
I am passing a CimInstance to a function and receiving it as PSCustomObject type.
Send CimInstance receive as [PSCustomObject] -> at target it remains CimInstance object type
Send CimInstance receive as [CimInstance] -> at target it remains CimInstance object type
Send CimInstance receive as [CimInstance[]] -> at target it turn to CimInstance array type