Cache directory lookups to reduce API calls

Added logic to cache users, groups, devices, and service principals lookups in Azure Table Storage for one day. This reduces repeated bulk API requests and improves performance by using cached data when available.

Author: JohnDuprey

Modules/CIPPCore/Public/Webhooks/Test-CIPPAuditLogRules.ps1

@@ -148,39 +148,76 @@ function Test-CIPPAuditLogRules {
             }
         }
 
-        # Collect bulk data for users/groups/devices/applications
-        $Requests = @(
-            @{
-                id     = 'users'
-                url    = '/users?$select=id,displayName,userPrincipalName,accountEnabled&$top=999'
-                method = 'GET'
-            }
-            @{
-                id     = 'groups'
-                url    = '/groups?$select=id,displayName,mailEnabled,securityEnabled&$top=999'
-                method = 'GET'
-            }
-            @{
-                id     = 'devices'
-                url    = '/devices?$select=id,displayName,deviceId&$top=999'
-                method = 'GET'
-            }
-            @{
-                id     = 'servicePrincipals'
-                url    = '/servicePrincipals?$select=id,displayName&$top=999'
-                method = 'GET'
-            }
-        )
-        $Response = New-GraphBulkRequest -TenantId $TenantFilter -Requests $Requests
+        $Table = Get-CIPPTable -tablename 'cacheauditloglookups'
+        $1dayago = (Get-Date).AddDays(-1).ToUniversalTime().ToString('yyyy-MM-ddTHH:mm:ssZ')
+        $Lookups = Get-CIPPAzDataTableEntity @Table -Filter "PartitionKey eq '$TenantFilter' and Timestamp gt datetime'$1dayago'"
+        if (!$Lookups) {
+            # Collect bulk data for users/groups/devices/applications
+            $Requests = @(
+                @{
+                    id     = 'users'
+                    url    = '/users?$select=id,displayName,userPrincipalName,accountEnabled&$top=999'
+                    method = 'GET'
+                }
+                @{
+                    id     = 'groups'
+                    url    = '/groups?$select=id,displayName,mailEnabled,securityEnabled&$top=999'
+                    method = 'GET'
+                }
+                @{
+                    id     = 'devices'
+                    url    = '/devices?$select=id,displayName,deviceId&$top=999'
+                    method = 'GET'
+                }
+                @{
+                    id     = 'servicePrincipals'
+                    url    = '/servicePrincipals?$select=id,displayName&$top=999'
+                    method = 'GET'
+                }
+            )
+            $Response = New-GraphBulkRequest -TenantId $TenantFilter -Requests $Requests
+            $Users = ($Response | Where-Object { $_.id -eq 'users' }).body.value
+            $Groups = ($Response | Where-Object { $_.id -eq 'groups' }).body.value ?? @()
+            $Devices = ($Response | Where-Object { $_.id -eq 'devices' }).body.value ?? @()
+            $ServicePrincipals = ($Response | Where-Object { $_.id -eq 'servicePrincipals' }).body.value
+            # Cache the lookups for 1 day
+            $Entities = @(
+                @{
+                    PartitionKey = $TenantFilter
+                    RowKey       = 'users'
+                    Data         = [string]($Users | ConvertTo-Json -Compress)
+                }
+                @{
+                    PartitionKey = $TenantFilter
+                    RowKey       = 'groups'
+                    Data         = [string]($Groups | ConvertTo-Json -Compress)
+                }
+                @{
+                    PartitionKey = $TenantFilter
+                    RowKey       = 'devices'
+                    Data         = [string]($Devices | ConvertTo-Json -Compress)
+                }
+                @{
+                    PartitionKey = $TenantFilter
+                    RowKey       = 'servicePrincipals'
+                    Data         = [string]($ServicePrincipals | ConvertTo-Json -Compress)
+                }
+            )
+            # Save the cached lookups
+            Add-CIPPAzDataTableEntity @Table -Entity $Entities -Force
+            Write-Information "Cached directory lookups for tenant $TenantFilter"
+        } else {
+            # Use cached lookups
+            $Users = ($Lookups | Where-Object { $_.RowKey -eq 'users' }).Data | ConvertFrom-Json
+            $Groups = ($Lookups | Where-Object { $_.RowKey -eq 'groups' }).Data | ConvertFrom-Json
+            $Devices = ($Lookups | Where-Object { $_.RowKey -eq 'devices' }).Data | ConvertFrom-Json
+            $ServicePrincipals = ($Lookups | Where-Object { $_.RowKey -eq 'servicePrincipals' }).Data | ConvertFrom-Json
+            Write-Information "Using cached directory lookups for tenant $TenantFilter"
+        }
 
         # partner users
         $PartnerUsers = New-GraphGetRequest -uri "https://graph.microsoft.com/beta/users?`$select=id,displayName,userPrincipalName,accountEnabled&`$top=999" -AsApp $true -NoAuthCheck $true
 
-        $Users = ($Response | Where-Object { $_.id -eq 'users' }).body.value
-        $Groups = ($Response | Where-Object { $_.id -eq 'groups' }).body.value ?? @()
-        $Devices = ($Response | Where-Object { $_.id -eq 'devices' }).body.value ?? @()
-        $ServicePrincipals = ($Response | Where-Object { $_.id -eq 'servicePrincipals' }).body.value
-
         Write-Warning '## Audit Log Configuration ##'
         Write-Information ($Configuration | ConvertTo-Json -Depth 10)