Set-vRAMachineReservations.ps1

<#
.SYNOPSIS
    Script that changes vRA managed machine reservations.
.DESCRIPTION
    Leveraging an existing connection to vRA and a pre-configured cloudclient installation,
    find all managed machines on a given OldReservation and attempt to change them to a
    given NewReservation.
.EXAMPLE
    PS C:\> Set-vRAMachineReservation.ps1
    Uses defaults to change all machines on the "Windows - 01" reservation 
    to the "Windows - 02" reservation
.EXAMPLE
    PS C:\> Set-vRAMachineReservation.ps1 -OldReservation "Res - 01" -NewReservation "Res - 02"
    Finds all vRA machines on the "Res - 01" reservation and changes them to the
    "Res - 02" Reservation
.EXAMPLE
    PS C:\> Set-vRAMachineReservation.ps1 -TargetVMs "Test01","Test02","Test03"
    Attempts to find the three test VMs in vRA, and if they are a member of the default OldReservation,
    "Windows - 01", will attempt to change their reservation to the default NewReservation,
    "Windows - 02"
.EXAMPLE
    PS C:\> Set-vRAMachineReservation.ps1 -TargetVMs "Test01" -OldReservation "Res - 01"
    Attempts to find the Test01 VM in vRA, and if it is a member of the "Res - 01" reservation, will
    attempt to change its reservation to the default NewReservation, "Windows - 02"
.PARAMETER OldReservation
    The existing reservation that should be changed
.PARAMETER NewReservation
    The new reservation for all machines found on existing
.PARAMETER TargetVMs
    An array of VM names to target for reservation changes
#>

[CmdletBinding()]
param(
    [System.String] $OldReservation = "Windows - 01",
    [System.String] $NewReservation = "Windows - 02",
        
    [ValidateScript( {
            Test-Path -Path $_ -Type Container
        })]
    [System.String] $CloudClientPath = "C:\temp\cloudclient\4.4.0\VMware_vRealize_CloudClient-4.4.0-5511232",
    [System.String[]] $TargetVMs
)
process {

    # CloudClient doesn't like spaces. We need to escape them
    $NewReservation = $NewReservation -replace " ", "\ "

    # Initialize Values
    $AllResources = @()
    $Page = 1

    # If we're not asking for a specific set of VMs, grab everything.
    if (! $TargetVMs) {
        <#
            vRA uses pagnation to restrict how many results are returned. It will return *at most* 100
            results for a given "page". To fully get all resources, we must leverage a $Count variable
            to track how many results we have and increment the page for every time we get back 100
            results.
        #>
        do {
            # Write out some progress
            $ProgressSplat = @{
                Activity = "Analyzing Resources"
                Status   = "Current page $Page"
            }
            Write-Progress @ProgressSplat

            # Get the vRA Resources (e.g. Machines) for this page. WithExtendedData includes the current
            # reservation
            $Group = Get-vRAResource -Page $Page -WithExtendedData

            # Grab the count of how many objects were retrieved
            $Count = $Group.count

            # Increment our page counter
            $Page ++

            # Add this group to the larger AllResources array
            $AllResources += $Group
        } while ($Count -ge 100) 
    }
    else {
        
        # Loop through every individual vm in the TargetVMs list
        foreach ($TargetVM in $TargetVMs) {
            $AllResources += Get-vRAResource -Name $TargetVM
        }
    }

    # Initialize our list of machines
    $List = @()

    # Parse every resource we retrieved above
    foreach ($Resource in $AllResources) {

        # If this resource's reservation matches the old reservation, add it to the list
        if ($Resource.data.machinereservationname -match $OldReservation) {
            Write-Information -MessageData "$OldReservation participant: $($Resource.name)" -InformationAction Continue
            $List += $Resource.name
        }
    }

    # CloudClient needs the MachineIDs as a comma separated list
    $MachineIDs = $List -join ","

    # Call the cloudclient executable, passing in the MachineIDs and New Reservation
    $CloudClientBat = Join-Path -Path $CloudClientPath -ChildPath "\bin\cloudclient.bat"
    & $CloudClientBat vra machines change reservation --ids $MachineIDs --reservationName $NewReservation
}