To show some Azure Graph things

ResourcesWithNoTagsFix.ps1

$rgwithwrongtags = $results #| where resourcebilling -eq 'somedefaultvalue'
$count = $rgwithwrongtags.Count
foreach ($resource in $rgwithwrongtags) {
    $context = Get-AzContext

    $excludedtypes = 'microsoft.compute/virtualmachines/extensions','microsoft.network/privatednszones/virtualnetworklinks','microsoft.network/privatednszones'
    if ($resource.type -notin $excludedtypes) {
        Set-BillingTag -resource $resource -billingtag $resource.rgbilling
    }
    else {
        $message = "We will not set tags on the resource {0} in Resource Group {1} as it is a {2}" -f $resource.name, $resource.resourceGroup, $resource.type
        Write-PSFMessage $message -Level Significant
    }
    $count --
    $message = "We have {0} left to do" -f $count
    Write-PSFMessage $message -Level Significant
}

Set-BillingTag.ps1

function Set-BillingTag {
    param(
        $resource,
        $billingtag
    )
    $context = Get-AzContext
    if ($resource.subscriptionId -ne $context.Subscription.Id) {
        Set-AzContext -SubscriptionId $resource.subscriptionId 
        $context = Get-AzContext
        $message = "swapped to {0} subscription" -f $context.Subscription.Name
        Write-PSFMessage $message -Level Significant -Verbose
    }
    try {
        $message = "We will set the resource {0} in Resource Group {1} to have the billing tag {2} instead of {3}" -f $resource.name, $resource.resourceGroup, $billingtag, $resource.resourcebilling
        Write-PSFMessage $message -Level Significant
        $tags = (Get-AzResource -ResourceId $resource.resourceId).Tags
        $tags.billing = $billingtag
        Set-AzResource -ResourceId $resource.resourceId -Tag $tags -Confirm:$false -Force -ErrorAction Stop | Out-Null
    }
    catch {
        $message = "Failed to set the tags on resource {0} in Resource Group {1} type {2}" -f $resource.name, $resource.resourceGroup, $resource.type
        Write-PSFMessage $message -Level Warning -ErrorRecord $_
    }

    $rg = Get-AzResourceGroup -Name  $resource.resourceGroup
    $tags = $rg.Tags
    # cos we need default tags el;se the policy bombs us out
    if($null -eq $tags.application){
        $tags.add('application','unknown')
    }
    if($null -eq $tags.creator){
        $tags.add('creator','unknown')
    }
    if($null -eq $tags.billing){
        $tags.add('billing','unknown')
    }
    if($tags.billing -ne $billingtag){
        try {
            $message = "We will set the  Resource Group {0} to have the billing tag {1} instead of {2}" -f  $resource.resourceGroup, $billingtag, $resource.resourcebilling
            Write-PSFMessage $message -Level Significant

            $tags.billing = $billingtag
            Set-AzResource -ResourceId $rg.resourceId -Tag $tags -Confirm:$false -Force -ErrorAction Stop | Out-Null
        }
        catch {
            $message = "Failed to set the tags on Resource Group {0} to have the billing tag {1} instead of {2}" -f  $resource.resourceGroup, $billingtag, $resource.resourcebilling
            Write-PSFMessage $message -Level Warning -ErrorRecord $_
        }
    }else {
        $message = "We do not need to set the tag on the Resource Group {0} " -f  $resource.resourceGroup
        Write-PSFMessage $message -Level Significant
    }

}

Somethings.ps1

# Install the Resource Graph module from PowerShell Gallery
## load a module

if(-not (Get-Module -Name Az.ResourceGraph -ListAvailable)){
    Install-Module -Name Az.ResourceGraph
}


# resource groups tags and resources tags to excel

$query = @"
resources
| where ['type'] !in~ ('microsoft.compute/virtualmachines/extensions','microsoft.network/privatednszones/virtualnetworklinks','microsoft.network/privatednszones') 
| where ['type'] !startswith "microsoft.network"
| join kind=inner (
    resourcecontainers
    | where type =~ 'microsoft.resources/subscriptions/resourcegroups'
    //| where tags['billing'] == 'beards are ace'
    | project subscriptionId, resourceGroup,rgtags=tags)
on subscriptionId, resourceGroup
//|limit 10 // for checking
| project-away subscriptionId1, resourceGroup1
| project subscriptionId,resourceGroup, name,rgbilling=rgtags['billing'], resourcebilling=tags['billing'], type,id
|where resourcebilling == ''

"@

$date = Get-Date -Format yyyyMMdd-HHmmss
$filename = './output/rgsandblankbillingtags-{0}.xlsx' -f $date


$pageSize = 1000
$iteration = 0
$searchParams = @{
    Query = $query
    First = $pageSize
}

$results = do {
    $iteration += 1
    Write-Verbose "Iteration #$iteration" -Verbose
    $pageResults = Search-AzGraph @searchParams
    $searchParams.Skip += $pageResults.Count
    $pageResults
} while ($pageResults.Count -eq $pageSize)
$results.Count
($results | where resourcebilling -eq 'the default entry').Count
$results | Export-Excel -Path $filename -WorksheetName 'Rgs and Tags' -AutoSize -AutoFilter

The Godfather, 1972

Leave the gun. Take the cannoli.