AWS Powershell Get-SSMMaintenanceWindowsTargets

[magrossm]

Dear All,

I have following function

function Get-SSMMaintenanceWindowMatch ($instance) {
  $mws = (Get-SSMMaintenanceWindowList -Region eu-west-1).WindowId
  for ($i=0; $i -le $mws.Length; $i++)  {
        $val = ((Get-SSMMaintenanceWindowTargets -region eu-west-1 -WindowId $mws[$i]).Targets).Values
        if (($val -eq $instance) {
        return $instance
        else {
        return $null
             }

      }
   }
}

The problem is that sometimes $val equals $null because the .Values in JSON are not existentn.

I get following error.

PS C:\WINDOWS\system32> Get-SSMMaintenanceWindowMatch $instanceId
Get-SSMMaintenanceWindowTargets : 1 validation error detected: Value null at 'windowId' failed to satisfy constraint: Member must not be 
null
At line:4 char:18
+ ...    $val = ((Get-SSMMaintenanceWindowTargets -region eu-west-1 -Win ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (Amazon.PowerShe...owTargetsCmdlet:GetSSMMaintenanceWindowTargetsCmdlet) [Get-SSMMaintenan 
   ceWindowTargets], InvalidOperationException
    + FullyQualifiedErrorId : Amazon.SimpleSystemsManagement.AmazonSimpleSystemsManagementException,Amazon.PowerShell.Cmdlets.SSM.GetSSMMa 
   intenanceWindowTargetsCmdlet

Any ideas? It works if an istance itself is registered to a maintenance window as a target but i want the loop to work if a member of the resulting array is null.

[matteo-prosperi]

According to the underlying API documentation, windowId is a required parameter, so a failure in using the cmdlet with a $null value is expected. Could you just exclude nulls from your list?

$mws = (Get-SSMMaintenanceWindowList -Region eu-west-1).WindowId | Where { $null -ne $_ }
ForEach ($item in $mws)
{