Copy all VM vApp properties from one vCenter server to another.

Copy-VmVAppProperty.ps1

function Copy-VmVAppProperty()
{
  <#
    .SYNOPSIS
    This function copes all VM vApp properties from the VMs in one VCenter server to another.

    .PARAMETER SourceVCenter
    Specifies the source vCenter server.

    .PARAMETER DestinationVCenter
    Specifies the destination vCenter server.

    .PARAMETER VM
    If specified, then only the specified VMs are affected.  The default is all VMs with vApp properties are affected.

    .EXAMPLE
    Copy-VmVAppProperty -SourceVCenter oldvcenter.domain.com -DestinationVCenter newvcenter.domain.com
  #>
  [CmdletBinding(SupportsShouldProcess)]
  param
  (
    [Parameter(Mandatory)]
    [string] $SourceVCenter,

    [Parameter(Mandatory)]
    [string] $DestinationVCenter,

    [string[]] $Vm
  )

  function Set-VAppProperties()
  {
    [CmdletBinding(SupportsShouldProcess)]
    param
    (
      [Parameter(Mandatory)]
      [PSObject] $SourceVm,

      [Parameter(Mandatory)]
      [PSObject] $DestinationVm,

      [Parameter(Mandatory)]
      [PSObject] $DestinationViServer

    )
    
    $sourceProps = $SourceVm.ExtensionData.Config.VAppConfig.Property
    $dstProps = $DestinationVm.ExtensionData.Config.VAppConfig.Property
    $propsToUpdate = @()

    foreach ( $prop in $sourceProps )
    {
      $dstProp = $dstProps | Where-Object { $_.Label -ieq $prop.Label }
      if ( $dstProp )
      {
        #  Update the property:
        if ( Compare-Object -ReferenceObject $prop -DifferenceObject $dstProp -Property Key,Id,Label,Type,DefaultValue,Value,Description )
        {
          Write-Verbose ("Property $($prop.Label) is different on the destination.  Updating...") 
          $propsToUpdate += New-Object -TypeName PSCustomObject -Property `
          @{
            "Type"     = "edit"
            "Property" = $prop
          }
        }
        else
        {
          Write-Verbose ("Property $($prop.Label) is the same on the destination.") 
        }
      }
      else
      {
        #  Add a new property:
        Write-Verbose ("Property $($prop.Label) is not present on the destination.  Adding...") 
        $propsToUpdate += New-Object -TypeName PSCustomObject -Property `
        @{
          "Type"     = "add"
          "Property" = $prop
        }
      }
    }

    if ( $propsToUpdate )
    {
      $vmSpec = New-Object VMware.Vim.VirtualMachineConfigSpec
      $vmSpec.vAppConfig = New-Object VMware.Vim.VmConfigSpec
      $vmspec.vAppConfig.property = New-Object VMware.Vim.VAppPropertySpec[] ($propsToUpdate.Count)

      foreach ( $prop in $propsToUpdate )
      {
        $new = New-Object VMware.Vim.VAppPropertySpec
        $new.operation = $prop.Type
        $new.Info = $prop.Property
        $vmSpec.vAppConfig.Property += $new
      }
      
      if ( $PSCmdlet.ShouldProcess($DestinationVm.Name, "Update VM with new custom properties") )
      {
        Write-Host ("Configuring VM $($DestinationVm.Name) with new properties...  ") -NoNewline
        $taskId = $DestinationVm.ExtensionData.ReconfigVM_Task($vmSpec)
    
        $start = Get-Date
        while ( (Get-Task -Server $DestinationViServer | Where-Object { $_.Id -ieq $taskId.ToString() -and $_.State -ine "Success" }) -and (New-TimeSpan -Start $start) -le "00:05:00" )
        {
          Start-Sleep -Seconds 5
          Write-Verbose ("Waiting for task to finish...")
        }
    
        $task = Get-Task -Server $DestinationViServer | Where-Object { $_.Id -ieq $taskId.ToString() }
        Write-Verbose ("Reconfiguration task submitted.")
        Write-Verbose ($task | Format-List | Out-String)
    
        if ( $task -and $task.State -ieq "Success" )
        {
          Write-Host ("Successful.") -ForegroundColor Green
        }
        else
        {
          Write-Host ("Failed - $($task.Result)") -ForegroundColor Red
        }
      }
  
      $DestinationVm = Get-Vm -Server $DestinationViServer -Name $DestinationVm.Name
    }
    else
    {
      Write-Host ("There are no properties to update on VM $($DestinationVm.Name).")
    }
  }
  
  Import-Module Vmware.VimAutomation.Core -ErrorAction Stop

  $srcCon = Connect-ViServer $SourceVCenter
  $dstCon = Connect-viServer $DestinationVCenter 

  $srcVms = Get-VM -Server $srcCon | Where-Object { $_.ExtensionData.Config.VAppConfig.Property }
  $dstVms = Get-VM -Server $dstCon
  
  foreach ( $sv in $srcVms | Where-Object { !$Vm -or $Vm -icontains $_.Name } )
  {
    $dst = $dstVms | Where-Object { $_.Name -ieq $sv.Name }

    if ( $dst )
    {
      Set-VAppProperties -SourceVm $sv -DestinationVm $dst -DestinationViServer $dstCon | Out-Null
    }
    else
    {
      Write-Warning ("Unable to find VM $($sv.Name) on the destination vCenter $($dstCon.Name)!")
    }
  }
  
}