Identify and export Untagged resources in subscription

This script is designed to identify resources that are missing tags in Azure subscriptions. It does this by first setting the tenant ID, which is a unique identifier for an Azure tenant. Then it gets all subscriptions in the tenant using the Get-AzSubscription cmdlet and stores them in the $subscriptions variable.

The script then iterates through each subscription in $subscriptions and does the following:

1. Creates an array called $untaggedResources to store the untagged resources for the subscription.
2. Gets all resource groups in the subscription using the Get-AzResourceGroup cmdlet and stores them in the $resourceGroups variable.
3. For each resource group, the script gets all resources in the resource group using the Get-AzResource cmdlet and stores them in the $resources variable.
4. For each resource, the script checks if the resource has no tags. If it does not have any tags, the script adds the resource to the $untaggedResources array.
5. After all resource groups have been processed, the script outputs the number of untagged resources in the subscription and exports the list of untagged resources to a CSV file in the c:\temp directory. The CSV file will be named $subscription-untaggedresources.csv, where $subscription is the name of the subscription.

# Set the tenant ID
$tenantId = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'

# Get all subscriptions in the tenant
$subscriptions = Get-AzSubscription -TenantId $tenantId

foreach($subscription in $subscriptions)
{


 $Path = "c:\temp"

# Create an array to store the untagged resources
$untaggedResources = @()

# Get all resource groups in the subscription
$resourceGroups = Get-AzResourceGroup

# Iterate through each resource group
foreach ($resourceGroup in $resourceGroups) {
    # Get all resources in the resource group
    $resources = Get-AzResource -ResourceGroupName $resourceGroup.ResourceGroupName

    # Iterate through each resource
    foreach ($resource in $resources) {
        # Check if the resource has no tags
        if ([string]::IsNullOrEmpty($resource.Tags)) {
            # Add the resource to the untagged resources array
            $untaggedResources += $resource
        }
    }
}

# Print the number of untagged resources
Write-Output "Number of untagged resources: $($untaggedResources.Count)"


$untaggedResources | Select-Object -Property Name, Resourcegroupname, Resourcetype, Tags | Export-Csv -path "$Path\$subscription-untaggedresources.csv" -NoTypeInformation 


}

We can modify this further according to custom requirements.

Please find the code in resposirory:

https://github.com/riyasriy/Powershell/blob/main/export-untagged-resources.ps1

If you need any assistance with the script, please leave a comment below.