Get-AzClusterReport.ps1

param (
    [String]$TenantId = "ed2da482-854d-467a-a6c5-a56a9c91be6d"
)

$clusterArr = Get-AzSubscription -TenantId $TenantId | ForEach-Object { $null = Set-AzContext -Subscription $_.SubscriptionId -Tenant $TenantId ; Get-AzAksCluster }
$resultArr = [System.Collections.ArrayList]@()

function GetNodePoolMaxIp {
    param (
        [Microsoft.Azure.Commands.Aks.Models.PSContainerServiceAgentPoolProfile]$AgentPoolProfile
    )

    $maxIpCount = $AgentPoolProfile.MaxCount * $AgentPoolProfile.MaxPods

    if (-not $maxIpCount) {
        $maxIpCount = $AgentPoolProfile.Count * $AgentPoolProfile.MaxPods
    }
    return $maxIpCount
}

function GetAksUpgradePath {
    param (
        [Microsoft.Azure.PowerShell.Cmdlets.Aks.Models.Api20200901.ManagedClusterUpgradeProfile]$UpgradeProfile 
    )

    return ($UpgradeProfile.ControlPlaneProfileUpgrade | Where-Object { $_.IsPreview -ne $true } | Sort-Object -Property KubernetesVersion -Descending -Top 1).KubernetesVersion
}

function cidrToIpRange {
    param (
        [string] $cidrNotation
    )

    $addr, $maskLength = $cidrNotation -split '/'
    [int]$maskLen = 0
    if (-not [int32]::TryParse($maskLength, [ref] $maskLen)) {
        throw "Cannot parse CIDR mask length string: '$maskLen'"
    }
    if (0 -gt $maskLen -or $maskLen -gt 32) {
        throw "CIDR mask length must be between 0 and 32"
    }
    $ipAddr = [Net.IPAddress]::Parse($addr)
    if ($ipAddr -eq $null) {
        throw "Cannot parse IP address: $addr"
    }
    if ($ipAddr.AddressFamily -ne [Net.Sockets.AddressFamily]::InterNetwork) {
        throw "Can only process CIDR for IPv4"
    }

    $shiftCnt = 32 - $maskLen
    $mask = -bnot ((1 -shl $shiftCnt) - 1)
    $ipNum = [Net.IPAddress]::NetworkToHostOrder([BitConverter]::ToInt32($ipAddr.GetAddressBytes(), 0))
    $ipStart = ($ipNum -band $mask) + 1
    $ipEnd = ($ipNum -bor (-bnot $mask)) - 1

    # return as tuple of strings:
    $firstAddress = ([BitConverter]::GetBytes([Net.IPAddress]::HostToNetworkOrder($ipStart)) | ForEach-Object { $_ } ) -join '.'
    $lastAddress = ([BitConverter]::GetBytes([Net.IPAddress]::HostToNetworkOrder($ipEnd)) | ForEach-Object { $_ } ) -join '.'
    return (1 | Select-Object -Property @{Name = 'FirstIpAddress'; Expression = { $firstAddress } }, @{Name = 'LastIpAddress'; Expression = { $lastAddress } })
}

# $start, $end = cidrToIpRange "192.168.100.14/24"
# Write-Host "Start: $start, end: $end"

# $start, $end = cidrToIpRange "10.77.1.1/18"
# Write-Host "Start: $start, end: $end"


function New-IPRange ($start, $end) {
    # created by Dr. Tobias Weltner, MVP PowerShell
    $ip1 = ([System.Net.IPAddress]$start).GetAddressBytes()
    [Array]::Reverse($ip1)
    $ip1 = ([System.Net.IPAddress]($ip1 -join '.')).Address
    $ip2 = ([System.Net.IPAddress]$end).GetAddressBytes()
    [Array]::Reverse($ip2)
    $ip2 = ([System.Net.IPAddress]($ip2 -join '.')).Address

    for ($x = $ip1; $x -le $ip2; $x++) {
        $ip = ([System.Net.IPAddress]$x).GetAddressBytes()
        [Array]::Reverse($ip)
        $ip -join '.'
    }
}

foreach ($clusterObj in $clusterArr) {
    $null = Set-AzContext -Subscription ($clusterObj.Id -split "/")[2] -Tenant $TenantId
    $maxUpgrade = GetAksUpgradePath(Get-AzAksUpgradeProfile -ClusterName $clusterObj.Name -ResourceGroupName $clusterObj.ResourceGroupName)
    $subscriptionName = (Get-AzContext).subscription.Name
    $networkPlugin = $clusterObj.NetworkProfile.NetworkPlugin
    $npArr = $clusterObj.AgentPoolProfiles | Select-Object -Property Name, OrchestratorVersion, MaxCount, MaxPods, VnetSubnetID, @{Name = 'MaxIpCount'; Expression = { GetNodePoolMaxIp($_) } }
    foreach ($np in $npArr) {
        $subnetObj = Get-AzVirtualNetworkSubnetConfig -ResourceId $np.VnetSubnetID
        $totalAddressCount = (New-IPRange (cidrToIpRange($subnetObj.AddressPrefix)).FirstIpAddress (cidrToIpRange($subnetObj.AddressPrefix)).LastIpAddress | Measure-Object).Count
        $consumedAddressCount = ($subnetObj.IpConfigurations | Measure-Object).Count
        $tmpObj = $clusterObj | Select-Object -Property @{Name = 'SubscriptionName'; Expression = { $subscriptionName } }, Name, KubernetesVersion, @{Name = 'MaxUpgradeVersion'; Expression = { $maxUpgrade } }, @{Name = 'NodePoolName'; Expression = { $np.Name } }, @{Name = 'OrchestratorVersion'; Expression = { $np.OrchestratorVersion } }, @{Name = 'MaxIpCount'; Expression = { $np.MaxIpCount } }, @{Name = 'SubnetAddressCount'; Expression = { $totalAddressCount } }, @{Name = 'ConsumedAddressCount'; Expression = { $consumedAddressCount } }, @{Name = 'NetworkPlugin'; Expression = { $networkPlugin } }, @{Name = 'NodePoolSubnetId'; Expression = { $np.VnetSubnetID } }
        $null = $resultArr.Add($tmpObj)
    }
}
return $resultArr