Private/Deallocate-AvdSessionHost.ps1

function DeallocateAvdSessionHost {
    <#
    .SYNOPSIS
    Deallocates AVD Session hosts in a specific hostpool.
    .DESCRIPTION
    It is almost the same as the Stop-AvdSessionHost command but this function also deallocates the session host in a specific Azure Virtual Desktop hostpool. Deallocated machines does not have an Azure consumption which saves money.
    .PARAMETER HostpoolName
    Enter the AVD Hostpool name
    .PARAMETER ResourceGroupName
    Enter the AVD Hostpool resourcegroup name
    .PARAMETER Name
    Enter the session hosts name
    .PARAMETER Id
    Enter the sessionhost's resource ID
    .PARAMETER Force
    Use this switch parameter to force deallocate all machine. Only needed when if you did not provide a sessionhost name.
    .EXAMPLE
    Deallocate-AvdSessionHost -HostpoolName avd-hostpool-personal -ResourceGroupName rg-avd-01 -Force
    .EXAMPLE
    Deallocate-AvdSessionHost -HostpoolName avd-hostpool-personal -ResourceGroupName rg-avd-01 -Name avd-host-1.avd.domain
    .EXAMPLE
    Get-AvdSessionHost -HostpoolName avd-hostpool-personal -ResourceGroupName rg-avd-01 -Name avd-host-1.avd.domain | Deallocate-AvdSessionHost
    #>

    [CmdletBinding(DefaultParameterSetName = 'All')]
    param
    (
        [parameter(Mandatory, ParameterSetName = 'All')]
        [parameter(Mandatory, ParameterSetName = 'Hostname')]
        [ValidateNotNullOrEmpty()]
        [string]$HostpoolName,
    
        [parameter(Mandatory, ParameterSetName = 'All')]
        [parameter(Mandatory, ParameterSetName = 'Hostname')]
        [ValidateNotNullOrEmpty()]
        [string]$ResourceGroupName,
    
        [parameter(Mandatory, ParameterSetName = 'All')]
        [parameter(Mandatory, ParameterSetName = 'Hostname')]
        [ValidateNotNullOrEmpty()]
        [string]$Name,

        [parameter(Mandatory, ParameterSetName = 'Resource', ValueFromPipelineByPropertyName)]
        [ValidateNotNullOrEmpty()]
        [string]$Id,

        [parameter(ParameterSetName = 'All')]
        [ValidateNotNullOrEmpty()]
        [switch]$Force
    )
    Begin {
        Write-Verbose "Deallocating session hosts"
        AuthenticationCheck
        $token = GetAuthToken -resource $global:AzureApiUrl
        $sessionHostParameters = @{
            hostpoolName      = $HostpoolName
            resourceGroupName = $ResourceGroupName
        }
        $apiVersion = "?api-version=2022-03-01"
    }
    Process {
        switch ($PsCmdlet.ParameterSetName) {
            All {
                CheckForce -Force:$Force -Task $MyInvocation.MyCommand
            }
            Hostname {
                $Name = ConcatSessionHostName -name $Name
                $sessionHostParameters.Add("Name", $Name)
            }
            Resource {
                Write-Verbose "Got a resource object, looking for $Id"
                $sessionHostParameters = @{
                    Id =  $Id
                }
            }
            default {

            }
        }
        try {
            $sessionHosts = Get-AvdSessionHost @sessionHostParameters
        }
        catch {
            Throw "No sessionhosts ($name) found in $HostpoolName ($ResourceGroupName), $_"
        }
        $sessionHosts | ForEach-Object {
            try {
                Write-Verbose "Found $($sessionHosts.Count) host(s)"
                Write-Verbose "Deallocating $($_.name)"
                $powerOffParameters = @{
                    uri     = "{0}{1}/deallocate{2}" -f $global:AzureApiUrl, $_.properties.resourceId, $apiVersion
                    Method  = "POST"
                    Headers = $token
                }
                Invoke-RestMethod @powerOffParameters
                Write-Information -MessageData "$($_.name) deallocated" -InformationAction Continue
            }
            catch {
                Throw "Not able to deallocate $($_.name), $_"
            }
        }
    }       
}