Remove-ExpiredResourceGroups.ps1

# Get variables
$tagName = "ExpirationDate"
$prodTagValue = "Production"
$emailFrom = Get-AutomationVariable -Name "EmailFrom"
$emailTo = Get-AutomationVariable -Name "EmailTo"
$smtpServer = Get-AutomationVariable -Name "SmtpServer"
$logPath = "C:\Temp\AzureResourceGroupDeletion.log"
$daysBeforeExpiration = Get-AutomationVariable -Name "DaysBeforeExpiration"

# Get all resource groups with the ExpirationDate tag
$resourceGroups = Get-AzResourceGroup | Where-Object {$_.Tags.ContainsKey($tagName)}

# Loop through each resource group
foreach ($resourceGroup in $resourceGroups) {
    # Check if the Environment tag equals Production, skip if it does
    if ($resourceGroup.Tags.Environment -eq $prodTagValue) {
        continue
    }
    
    # Get the expiration date from the ExpirationDate tag
    $expirationDate = [datetime]::ParseExact($resourceGroup.Tags.ExpirationDate, "yyyy-MM-dd", $null)

    # Check if the expiration date is less than the specified number of days from now
    if ($expirationDate -lt (Get-Date).AddDays($daysBeforeExpiration)) {
        # Send email notification that resource group will be deleted on expiration date
        $subject = "Azure Resource Group will be deleted on $expirationDate"
        $body = "The resource group $($resourceGroup.Name) will be deleted on $expirationDate."
        Send-MailMessage -From $emailFrom -To $emailTo -Subject $subject -Body $body -SmtpServer $smtpServer
    }
    
    # Check if the expiration date has already passed
    if ($expirationDate -lt (Get-Date)) {
        # Try to remove the resource group
        try {
            Remove-AzResourceGroup -Name $resourceGroup.Name -Force -ErrorAction Stop

            # Send email notification that resource group was deleted
            $subject = "Azure Resource Group Deleted: $($resourceGroup.Name)"
            $body = "The resource group $($resourceGroup.Name) was successfully deleted."
            Send-MailMessage -From $emailFrom -To $emailTo -Subject $subject -Body $body -SmtpServer $smtpServer
        }
        # If removal fails, log the error and send an email summary
        catch {
            $errorMessage = $_.Exception.Message
            Add-Content $logPath "$($resourceGroup.Name): $errorMessage"
        }
    }
}