cls
function Get-AzureRmCachedAccessToken()
{
  # Get-AzureRmCachedAccessToken function is downloaded from https://gallery.technet.microsoft.com/scriptcenter/Easily-obtain-AccessToken-3ba6e593/
  $ErrorActionPreference = 'Stop'
  
  if(-not (Get-Module AzureRm.Profile)) {
    Import-Module AzureRm.Profile
  }
  $azureRmProfileModuleVersion = (Get-Module AzureRm.Profile).Version
  # refactoring performed in AzureRm.Profile v3.0 or later
  if($azureRmProfileModuleVersion.Major -ge 3) {
    $azureRmProfile = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile
    if(-not $azureRmProfile.Accounts.Count) {
      Write-Error "Ensure you have logged in before calling this function."    
    }
  } else {
    # AzureRm.Profile < v3.0
    $azureRmProfile = [Microsoft.WindowsAzure.Commands.Common.AzureRmProfileProvider]::Instance.Profile
    if(-not $azureRmProfile.Context.Account.Count) {
      Write-Error "Ensure you have logged in before calling this function."    
    }
  }
  
  $currentAzureContext = Get-AzureRmContext
  $profileClient = New-Object Microsoft.Azure.Commands.ResourceManager.Common.RMProfileClient($azureRmProfile)
  Write-Debug ("Getting access token for tenant" + $currentAzureContext.Subscription.TenantId)
  $token = $profileClient.AcquireAccessToken($currentAzureContext.Subscription.TenantId)
  $token.AccessToken
}

# Powershell Azure login requires https://docs.microsoft.com/en-us/powershell/azure/install-azurerm-ps
Login-AzureRmAccount 

# Using Get-AzureRmCachedAccessToken function to get logged in user access token powershell session
$TerraformAzureAccessToken = Get-AzureRmCachedAccessToken
$Context = $(Get-AzureRmContext |Select-object Subscription, Tenant)

# Putting access token in to a console avalible environemt variable for consumtion by Terraform  
[Environment]::SetEnvironmentVariable("ARM_ACCESSTOKEN", $TerraformAzureAccessToken , "Process")
[Environment]::SetEnvironmentVariable("ARM_SUBSCRIPTION_ID", $($Context.Subscription) , "Process")
[Environment]::SetEnvironmentVariable("ARM_TENANT_ID", $($Context.Tenant) , "Process")