From c266b59def955f2cf7995703abbc8e1edc7def4a Mon Sep 17 00:00:00 2001
From: Richard Nixon <richard.nixon@btinternet.com>
Date: Mon, 16 Dec 2019 18:27:35 +0000
Subject: [PATCH] Offload user filtering to Azure API to avoid resource
 problems in a large AD

 - Modify Azure::Graph.users to pass a filter parameter to Azure REST API
 - Modify AzurermAdUsers to pass a filter parameter to Azure::Graph.users

Signed-off-by: Richard Nixon <richard.nixon@btinternet.com>
---
 libraries/azurerm_ad_users.rb    | 11 ++++++++---
 libraries/support/azure/graph.rb |  5 ++++-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/libraries/azurerm_ad_users.rb b/libraries/azurerm_ad_users.rb
index cbefb96a0..51302fa2e 100644
--- a/libraries/azurerm_ad_users.rb
+++ b/libraries/azurerm_ad_users.rb
@@ -21,8 +21,9 @@ class AzurermAdUsers < AzurermPluralResource
              .register_column(:user_types,     field: :userType)
              .install_filter_methods_on_resource(self, :table)
 
-  def initialize
-    resp = graph.users
+  def initialize(params = {})
+    @params = params
+    resp = graph.users(@params)
     return if has_error?(resp)
 
     @table = resp
@@ -35,6 +36,10 @@ def guest_accounts
   end
 
   def to_s
-    'Azure Active Directory Users'
+    if @params[:filter]
+      "Azure Active Directory Users with filter( #{@params[:filter]} )"
+    else
+      'Azure Active Directory Users'
+    end
   end
 end
diff --git a/libraries/support/azure/graph.rb b/libraries/support/azure/graph.rb
index ccdf7ffc6..0b01e2e48 100644
--- a/libraries/support/azure/graph.rb
+++ b/libraries/support/azure/graph.rb
@@ -21,12 +21,15 @@ def user(id)
       )
     end
 
-    def users
+    def users(raw_params = {})
+      cooked_params = {}
+      cooked_params['$filter'] = raw_params[:filter] unless raw_params[:filter].nil?
       get(
         url:           "/#{tenant_id}/users",
         api_version:   '1.6',
         error_handler: handle_error,
         unwrap:        unwrap,
+        params:        cooked_params,
       )
     end