Azure Service Inventory Tool: Which of the 397 Services Do You Actually Use?

Service Type              Category    Count   Cost Tier   Deprecated
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Virtual Machines          Compute       156      High         No
Storage Accounts          Storage       423      Medium       No
Virtual Networks          Networking     44      Low          No
Network Interfaces        Networking    312      Free         No
Recovery Services Vault   Backup         12      Medium       No
Key Vault                 Security       18      Low          No
Log Analytics Workspace   Monitoring      8      Medium       No
Classic Storage Account   Storage         3      Medium       YES (migrate to v2)

Resources
| summarize 
    Count = count(),
    Subscriptions = make_set(subscriptionId),
    ResourceGroups = make_set(resourceGroup)
  by type
| extend 
    Provider = split(type, '/')[0],
    ServiceType = split(type, '/')[1]
| project Provider, ServiceType, Count, Subscriptions, ResourceGroups
| order by Count desc

<#
.SYNOPSIS
    Azure Service Inventory Tool
.DESCRIPTION
    Queries all subscriptions to determine which Azure services are actually in use.
    Creates an Excel-compatible CSV with service counts, categories, and metadata.
.EXAMPLE
    .\Get-AzureServiceInventory.ps1
    .\Get-AzureServiceInventory.ps1 -SubscriptionId "sub-id-here"
#>

param(
    [Parameter(Mandatory=$false)]
    [string]$SubscriptionId,

    [Parameter(Mandatory=$false)]
    [string]$OutputPath = ".\AzureServiceInventory.csv"
)

# Ensure Az.ResourceGraph module
if (-not (Get-Module -ListAvailable Az.ResourceGraph)) {
    Write-Host "Installing Az.ResourceGraph module..." -ForegroundColor Yellow
    Install-Module Az.ResourceGraph -Force -AllowClobber
}

Import-Module Az.ResourceGraph

# Check if logged in
$context = Get-AzContext
if (-not $context) {
    Write-Host "Not logged in to Azure. Running Connect-AzAccount..." -ForegroundColor Yellow
    Connect-AzAccount
}

Write-Host "`n🔍 Querying Azure Resource Graph for service inventory..." -ForegroundColor Cyan

# Build subscription scope
$subscriptionScope = if ($SubscriptionId) {
    @($SubscriptionId)
} else {
    (Get-AzSubscription | Where-Object {$_.State -eq 'Enabled'}).Id
}

Write-Host "📊 Scanning $($subscriptionScope.Count) subscription(s)..." -ForegroundColor Cyan

# Query all resource types
$query = @"
Resources
| summarize 
    Count = count(),
    SubscriptionCount = dcount(subscriptionId),
    Locations = make_set(location)
  by type
| extend 
    Provider = split(type, '/')[0],
    ServiceType = split(type, '/')[1]
| project Provider, ServiceType, Count, SubscriptionCount, Locations
| order by Count desc
"@

$results = Search-AzGraph -Query $query -Subscription $subscriptionScope -First 1000

Write-Host "✅ Found $($results.Count) distinct Azure service types in use`n" -ForegroundColor Green

# Service category mapping
$categoryMap = @{
    'Microsoft.Compute' = 'Compute'
    'Microsoft.Network' = 'Networking'
    'Microsoft.Storage' = 'Storage'
    'Microsoft.Web' = 'Web + Mobile'
    'Microsoft.Sql' = 'Databases'
    'Microsoft.DBforPostgreSQL' = 'Databases'
    'Microsoft.DBforMySQL' = 'Databases'
    'Microsoft.KeyVault' = 'Security'
    'Microsoft.ManagedIdentity' = 'Security'
    'Microsoft.Security' = 'Security'
    'Microsoft.OperationalInsights' = 'Monitoring'
    'Microsoft.Insights' = 'Monitoring'
    'Microsoft.Monitor' = 'Monitoring'
    'Microsoft.RecoveryServices' = 'Backup + DR'
    'Microsoft.Backup' = 'Backup + DR'
    'Microsoft.ContainerService' = 'Containers'
    'Microsoft.ContainerRegistry' = 'Containers'
    'Microsoft.Logic' = 'Integration'
    'Microsoft.ServiceBus' = 'Integration'
    'Microsoft.EventHub' = 'Integration'
    'Microsoft.Automation' = 'Management'
    'Microsoft.Resources' = 'Management'
    'Microsoft.Authorization' = 'Management'
}

# Cost tier estimation (rough)
$costTierMap = @{
    'virtualmachines' = 'High'
    'disks' = 'Medium'
    'snapshots' = 'Low'
    'storageaccounts' = 'Medium'
    'virtualnetworks' = 'Low'
    'networkinterfaces' = 'Free'
    'publicipaddresses' = 'Low'
    'loadbalancers' = 'Low'
    'applicationgateways' = 'High'
    'vaults' = 'Medium'  # Key Vault
    'servers' = 'High'   # SQL
    'workspaces' = 'Medium'  # Log Analytics
    'sites' = 'Medium'   # App Service
}

# Deprecated services
$deprecatedServices = @{
    'Microsoft.ClassicCompute/virtualMachines' = 'Migrate to Azure Resource Manager VMs'
    'Microsoft.ClassicStorage/storageAccounts' = 'Migrate to v2 Storage Accounts'
    'Microsoft.ClassicNetwork/virtualNetworks' = 'Migrate to ARM Virtual Networks'
}

# Build enriched inventory
$inventory = $results | ForEach-Object {
    $provider = $_.Provider
    $serviceType = $_.ServiceType
    $fullType = "$provider/$serviceType"

    $category = if ($categoryMap.ContainsKey($provider)) {
        $categoryMap[$provider]
    } else {
        'Other'
    }

    $costTier = if ($costTierMap.ContainsKey($serviceType.ToLower())) {
        $costTierMap[$serviceType.ToLower()]
    } else {
        'Unknown'
    }

    $deprecated = if ($deprecatedServices.ContainsKey($fullType)) {
        "YES - $($deprecatedServices[$fullType])"
    } else {
        'No'
    }

    $docsLink = "https://learn.microsoft.com/azure/?product=$($serviceType.ToLower())"

    [PSCustomObject]@{
        Provider = $provider
        ServiceType = $serviceType
        Category = $category
        Count = $_.Count
        SubscriptionCount = $_.SubscriptionCount
        Locations = ($_.Locations -join ', ')
        CostTier = $costTier
        Deprecated = $deprecated
        DocsLink = $docsLink
        Notes = ''  # For manual entry
        Owner = ''  # For manual entry
    }
}

# Export to CSV
$inventory | Export-Csv -Path $OutputPath -NoTypeInformation -Encoding UTF8

Write-Host "✅ Service inventory exported to: $OutputPath" -ForegroundColor Green
Write-Host "`n📊 Summary:" -ForegroundColor Cyan
Write-Host "   Total Services in Use: $($inventory.Count)" -ForegroundColor White
Write-Host "   Total Resources: $(($inventory | Measure-Object -Property Count -Sum).Sum)" -ForegroundColor White

# Category breakdown
$categoryBreakdown = $inventory | Group-Object Category | Sort-Object Count -Descending
Write-Host "`n📁 By Category:" -ForegroundColor Cyan
foreach ($cat in $categoryBreakdown) {
    Write-Host "   $($cat.Name): $($cat.Count) service types" -ForegroundColor White
}

# Check for deprecated services
$deprecatedCount = ($inventory | Where-Object {$_.Deprecated -ne 'No'}).Count
if ($deprecatedCount -gt 0) {
    Write-Host "`n⚠️  Warning: $deprecatedCount deprecated service(s) found!" -ForegroundColor Yellow
    $inventory | Where-Object {$_.Deprecated -ne 'No'} | ForEach-Object {
        Write-Host "   - $($_.ServiceType): $($_.Deprecated)" -ForegroundColor Yellow
    }
}

Write-Host "`n💡 Next Steps:" -ForegroundColor Cyan
Write-Host "   1. Open $OutputPath in Excel" -ForegroundColor White
Write-Host "   2. Add Owner and Notes columns for your team" -ForegroundColor White
Write-Host "   3. Filter by Category or CostTier" -ForegroundColor White
Write-Host "   4. Share with your team for service ownership mapping" -ForegroundColor White
Write-Host ""

# Run against all subscriptions
.\Get-AzureServiceInventory.ps1

# Run against specific subscription
.\Get-AzureServiceInventory.ps1 -SubscriptionId "your-sub-id"

# Custom output location
.\Get-AzureServiceInventory.ps1 -OutputPath "C:\Reports\ServiceInventory.csv"

ServiceType              Count   Owner
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Virtual Machines          156    Infrastructure Team
SQL Servers                23    Database Team
App Service Plans          45    Application Team
Storage Accounts          423    Unassigned ← Problem!

ServiceType          Count   CostTier   Monthly Cost (est)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Virtual Machines      156     High       $87,000
SQL Servers            23     High       $34,000
Application Gateways   12     High       $18,000

ServiceType                Count   Locations
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
SQL Servers                 23     eastus, westus
PostgreSQL Servers          8      eastus
MySQL Servers               4      centralus

# Add this to the script after building inventory
$costQuery = @"
{
  "type": "Usage",
  "timeframe": "MonthToDate",
  "dataset": {
    "granularity": "None",
    "aggregation": {
      "totalCost": {
        "name": "Cost",
        "function": "Sum"
      }
    },
    "grouping": [
      {
        "type": "Dimension",
        "name": "ResourceType"
      }
    ]
  }
}
"@

# Call Cost Management API for each subscription
# (Implementation left as exercise - requires Cost Management permissions)

ServiceType              Count   Owner
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Machine Learning Workspace  2     Unknown
Data Factory                1     Unknown
Container Registry          1     Unknown

ServiceType                      Count   Deprecated
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Classic Storage Accounts          12     YES
Classic Virtual Networks           3     YES

.\Get-AzureServiceInventory.ps1