Get-ChildItem "XDHyp:\HostingUnits\"

Start-BrokerRebootCycle -InputObject @(<Machine Catalog Name>) -RebootDuration 120 -WarningDuration 15 -WarningMessage <message> -WarningTitle <message>

#---------------------------------------------------------------------------
## Author: Aaron Parker
## Desc:   Using PowerShell to update a XenDesktop 7.x machine catalog 
## Date:   Oct 27, 2014
## Site:   http://stealthpuppy.com
#---------------------------------------------------------------------------

## Set variables for the target infrastructure
## ----------
$adminAddress = 'xd71.home.stealthpuppy.com' #The XD Controller we're going to execute against
$xdControllers = 'xd71.home.stealthpuppy.com'

## Hypervisor and storage resources
## These need to be configured in Studio prior to running this script
## This script is hypervisor and management agnostic - just point to the right infrastructure
$storageResource = "HV2-EVOPro" #Storage
$hostResource = "Lab vCenter" #Hypervisor management

## Master image properties
$machineCatalogName = "Windows 8 vSphere"
$masterImage ="Windows8*"
$snapshot = "VDA 7.6"

$messageDetail = "Your computer has been updated and will be automatically restarted in 15 minutes."
$messageTitle = "Help desk message"
## ----------

## Load the Citrix PowerShell modules
Write-Verbose "Loading Citrix XenDesktop modules."
Add-PSSnapin Citrix*

## Get information from the hosting environment via the XD Controller
## Get the storage resource
Write-Verbose "Gathering storage and hypervisor connections from the XenDesktop infrastructure."
$hostingUnit = Get-ChildItem -AdminAddress $adminAddress "XDHyp:\HostingUnits" | Where-Object { $_.PSChildName -like $storageResource } | Select-Object PSChildName, PsPath
## Get the hypervisor management resources
$hostConnection = Get-ChildItem -AdminAddress $adminAddress "XDHyp:\Connections" | Where-Object { $_.PSChildName -like $hostResource }

## Get the broker connection to the hypervisor management
## http://support.citrix.com/proddocs/topic/citrix-broker-admin-v2-xd75/get-brokerhypervisorconnection-xd75.html
$brokerHypConnection = Get-BrokerHypervisorConnection -AdminAddress $adminAddress -HypHypervisorConnectionUid $hostConnection.HypervisorConnectionUid

## Set a provisioning scheme for the update process
## http://support.citrix.com/proddocs/topic/citrix-machinecreation-admin-v2-xd75/set-provschememetadata-xd75.html
$ProvScheme = Set-ProvSchemeMetadata -AdminAddress $adminAddress -Name 'ImageManagementPrep_DoImagePreparation' -ProvisioningSchemeName $machineCatalogName -Value 'True'

## Get the master VM image from the same storage resource we're going to deploy to. Could pull this from another storage resource available to the host
Write-Verbose "Getting the snapshot details for the catalog: $machineCatalogName"
$VM = Get-ChildItem -AdminAddress $adminAddress "XDHyp:\HostingUnits\$storageResource" | Where-Object { $_.ObjectType -eq "VM" -and $_.PSChildName -like $masterImage }
## Get the snapshot details. This code will grab a specific snapshot, although you could grab the last in the list assuming it's the latest.
$VMSnapshots = Get-ChildItem -AdminAddress $adminAddress $VM.FullPath -Recurse -Include *.snapshot
$TargetSnapshot = $VMSnapshots | Where-Object { $_.FullName -eq "$snapshot.snapshot" }

## Publish the image update to the machine catalog
## http://support.citrix.com/proddocs/topic/citrix-machinecreation-admin-v2-xd75/publish-provmastervmimage-xd75.html
$PubTask = Publish-ProvMasterVmImage -AdminAddress $adminAddress -MasterImageVM $TargetSnapshot.FullPath -ProvisioningSchemeName $machineCatalogName -RunAsynchronously
$provTask = Get-ProvTask -AdminAddress $adminAddress -TaskId $PubTask

## Track progress of the image update
Write-Verbose "Tracking progress of the machine creation task."
$totalPercent = 0
While ( $provTask.Active -eq $True ) {
    Try { $totalPercent = If ( $provTask.TaskProgress ) { $provTask.TaskProgress } Else {0} } Catch { }

    Write-Progress -Activity "Provisioning image update" -Status "$totalPercent% Complete:" -percentcomplete $totalPercent
    Sleep 15
    $provTask = Get-ProvTask -AdminAddress $adminAddress -TaskId $PubTask
}

## Start the desktop reboot cycle to get the update to the actual desktops
## http://support.citrix.com/proddocs/topic/citrix-broker-admin-v2-xd75/start-brokerrebootcycle-xd75.html
Start-BrokerRebootCycle -AdminAddress $adminAddress -InputObject @($machineCatalogName) -RebootDuration 60 -WarningDuration 15 -WarningMessage $messageDetail -WarningTitle $messageTitle