Stop-Start-AzureVM2.ps1

workflow Stop-Start-AzureVM2
{
    Param 
    (    
        [Parameter(Mandatory=$true)][ValidateNotNullOrEmpty()] 
        [String] 
        $credentialName,
        [Parameter(Mandatory=$true)][ValidateNotNullOrEmpty()] 
        [String] 
        $ResourceGroup,
        [Parameter(Mandatory=$true)][ValidateSet("Start","Stop")] 
        [String] 
        $Action 
    ) 
     
    $credential = Get-AutomationPSCredential -Name $credentialName
    $tennantId = Get-AutomationVariable -Name 'tennantId'
    Login-AzureRmAccount -Credential $credential -Tenantid $tennantId -ServicePrincipal
 
    $AzureVMs = Get-AzureRmVM -ResourceGroup $ResourceGroup
 
    if($Action -eq "Stop")
    { 
        Write-Output "Stopping VMs"; 
        foreach -parallel ($AzureVM in $AzureVMs) 
        { 
            $AzureVM | Stop-AzureRmVM -Force
        } 
    } 
    else 
    { 
        Write-Output "Starting VMs"; 
        foreach -parallel ($AzureVM in $AzureVMs) 
        { 
            $AzureVM | Start-AzureRmVM
        } 
    } 
}