1<#
2.SYNOPSIS
3    Checks Azure quota limits and current usage for a resource provider.
4.DESCRIPTION
5    Installs the quota CLI extension if needed, then queries quota limits and
6    current usage in a single call. Returns a table with limit, usage, and
7    available capacity for every quota (or a single quota when ResourceName is provided).
8.PARAMETER ResourceProvider
9    Azure resource provider namespace (e.g., "Microsoft.Compute", "Microsoft.Network").
10.PARAMETER Region
11    Azure region to check (e.g., "eastus", "westus2").
12.PARAMETER ResourceName
13    Quota resource name (e.g., "standardDSv3Family"). If omitted, returns all quotas.
14.PARAMETER SubscriptionId
15    Azure subscription ID. Defaults to the current subscription.
16.EXAMPLE
17    .\check-quota.ps1 -ResourceProvider Microsoft.Compute -Region eastus
18    # Shows limit, usage, and available capacity for ALL compute quotas in eastus
19.EXAMPLE
20    .\check-quota.ps1 -ResourceProvider Microsoft.Compute -Region eastus -ResourceName standardDSv3Family
21    # Shows limit, usage, and available capacity for the DSv3 VM family only
22#>
23param(
24    [Parameter(Mandatory)][string]$ResourceProvider,
25    [Parameter(Mandatory)][string]$Region,
26    [string]$ResourceName,
27    [string]$SubscriptionId
28)
29 
30$ErrorActionPreference = "Stop"
31 
32# Ensure the quota extension is installed
33$ext = az extension list --query "[?name=='quota'].name" -o tsv 2>$null
34if (-not $ext) {
35    Write-Host "Installing quota extension..."
36    az extension add --name quota --yes 2>$null
37}
38 
39# Resolve subscription
40if (-not $SubscriptionId) {
41    $SubscriptionId = az account show --query id -o tsv
42}
43 
44$scope = "/subscriptions/$SubscriptionId/providers/$ResourceProvider/locations/$Region"
45 
46Write-Host "Checking quotas in scope $scope"
47 
48if ($ResourceName) {
49    # Single-resource mode
50    Write-Host "Quota for '$ResourceName' ($ResourceProvider, $Region):"
51    Write-Host ""
52 
53    $limit = az quota show --resource-name $ResourceName --scope $scope -o json 2>$null | ConvertFrom-Json
54    $usage = az quota usage show --resource-name $ResourceName --scope $scope -o json 2>$null | ConvertFrom-Json
55 
56    $limitValue = $limit.properties.limit.value
57    $usageValue = $usage.properties.usages.value
58    $available = $limitValue - $usageValue
59 
60    [PSCustomObject]@{
61        Resource  = $ResourceName
62        Region    = $Region
63        Limit     = $limitValue
64        Usage     = $usageValue
65        Available = $available
66    } | Format-Table -AutoSize
67} else {
68    # All-quotas mode: fetch limits and usage, join by name
69    Write-Host "Quotas for $ResourceProvider in ${Region}:"
70    Write-Host ""
71 
72    $quotas = az quota list --scope $scope -o json 2>$null | ConvertFrom-Json
73    $usages = az quota usage list --scope $scope -o json 2>$null | ConvertFrom-Json
74 
75    $usageLookup = @{}
76    foreach ($u in $usages) {
77        $usageLookup[$u.name] = $u.properties.usages.value
78    }
79 
80    $results = foreach ($q in $quotas) {
81        $name = $q.name
82        $limitValue = $q.properties.limit.value
83        $usageValue = if ($usageLookup.ContainsKey($name)) { $usageLookup[$name] } else { 0 }
84        $available = $limitValue - $usageValue
85        [PSCustomObject]@{
86            Resource  = $name
87            Region    = $Region
88            Limit     = $limitValue
89            Usage     = $usageValue
90            Available = $available
91        }
92    }
93 
94    $results | Format-Table -AutoSize
95}
96