listAKSClustersWithoutAnyWorkloads.ps1

# TODO: 
# This script will not identify any clusters probably as in the system namespace there are always some workloads running. 
# Need to find a way to exclude system namespace from the list of workloads.

# Login to Azure
#Connect-AzAccount

# Get all AKS clusters
$aksClusters = Get-AzAKSCluster

# Initialize an array to store unused AKS clusters
$unusedAksClusters = @()

# Check each AKS cluster for nodes and workloads
foreach ($aksCluster in $aksClusters) {
    $resourceGroupName = $aksCluster.ResourceGroupName
    $aksClusterName = $aksCluster.Name

    # Get the nodes in the AKS cluster
    $nodes = Get-AzAKSNodePool -ResourceGroupName $resourceGroupName -ClusterName $aksClusterName

    # Get the workloads in the AKS cluster using kubectl
    Import-AzAksCredential -ResourceGroupName $resourceGroupName -Name $aksClusterName -Admin -Force -confirm:$false
     
    $systemNamespaces = @('kube-system', 'kube-public', 'kube-node-lease', 'azure-arc')
   
    $namespaces = & kubectl get namespaces -o jsonpath="{.items[*].metadata.name}" | `
        ForEach-Object { $_.Split(' ') } | Where-Object { $systemNamespaces -notcontains $_ }

    $workloads = @()
    foreach ($ns in $namespaces) {
        $pods = & kubectl get pods -n $ns
        if ($pods) { $workloads += $pods }
    }

    if ( $workloads.Count -eq 0) {
        $unusedAksClusters += $aksCluster
    }
}

# Display the unused AKS clusters
$unusedAksClusters | ForEach-Object {
    Write-Output "AKS Cluster: $($_.Name) - Resource Group: $($_.ResourceGroupName)"
}