Removing machines from Azure State Configuration (DSC)

I have been provisioning machines over an over trying to learn all the VM Extensions. One of the extensions that I have been playing with is the DSC extension. Every time I provision with this extension, it adds an additional record into the State Configuration, resulting in many stale machines. I wanted to clear out all the old machines. I couldn’t find a way to do it in PowerShell, so I figure out how to do it via the REST API (and PowerShell).

Here is the code to remove all machines from Azure State Configuration (DSC)

$SubscriptionId = "$($env:SubscriptionId)"
$TenantId       = "$($env:TenantId)" 
$ClientID       = "$($env:ClientID)"      
$ClientSecret   = "$($env:ClientSecret)"  
$TenantDomain   = "$($env:TenantDomain)" 
$loginURL       = "https://login.microsoftonline.com/$TenantId/oauth2/token"
$resource       = "https://management.core.windows.net/"    
$resourceGroupName = "YourResourceGroupName "
$automationAccountsName ="YourAutomationAccountsName "

# get the OAUTH token & prepare header
$body           = @{grant_type="client_credentials";resource=$resource;client_id=$ClientID;client_secret=$ClientSecret}
$oauth          = Invoke-RestMethod -Method Post -Uri $loginURL -Body $body
$headerParams = @{'Authorization'="$($oauth.token_type) $($oauth.access_token)"}

# main query to find all the nodes
$url="https://management.azure.com/subscriptions/$SubscriptionId/resourceGroups/$resourceGroupName/providers/Microsoft.Automation/automationAccounts/$automationAccountsName/nodes?api-version=2018-01-15"
$results=Invoke-RestMethod -Uri $url -Headers $headerParams -Method Get
# Loop through all the nodes and delete them all.
foreach ($node in $($results.value | Select-Object  -ExpandProperty properties | Select nodeid)){
$url="https://management.azure.com/subscriptions/$SubscriptionId/resourceGroups/$resourceGroupName/providers/Microsoft.Automation/automationAccounts/$automationAccountsName/nodes/$($node.nodeId)?api-version=2018-01-15"
Invoke-RestMethod -Uri $url -Headers $headerParams -Method Delete
}

Notes:

1. I put all my SPN info into environmental varaibles (easier to switch of needed)
2. Put in your RG name and Auutomation Account Name
3. Warning. This will delete all nodes!

HTH