From 2ec92186bc7bef257a2da43c6028411f2e1a9146 Mon Sep 17 00:00:00 2001
From: Dima Arnautov <dmitrii.arnautov@elastic.co>
Date: Thu, 21 Nov 2024 18:26:58 +0100
Subject: [PATCH] fallback to lazy nodes count to determine if ml autoscaling
 is enabled

---
 x-pack/plugins/ml/server/lib/node_utils.ts |  2 +-
 x-pack/plugins/ml/server/routes/system.ts  | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/x-pack/plugins/ml/server/lib/node_utils.ts b/x-pack/plugins/ml/server/lib/node_utils.ts
index d8098e3c43f42..9c5c0348f03da 100644
--- a/x-pack/plugins/ml/server/lib/node_utils.ts
+++ b/x-pack/plugins/ml/server/lib/node_utils.ts
@@ -33,7 +33,7 @@ export async function getMlNodeCount(client: IScopedClusterClient): Promise<MlNo
   return { count, lazyNodeCount };
 }
 
-export async function getLazyMlNodeCount(client: IScopedClusterClient) {
+export async function getLazyMlNodeCount(client: IScopedClusterClient): Promise<number> {
   const body = await client.asInternalUser.cluster.getSettings(
     {
       include_defaults: true,
diff --git a/x-pack/plugins/ml/server/routes/system.ts b/x-pack/plugins/ml/server/routes/system.ts
index d4127a7428397..150fc3c75a109 100644
--- a/x-pack/plugins/ml/server/routes/system.ts
+++ b/x-pack/plugins/ml/server/routes/system.ts
@@ -14,7 +14,7 @@ import { mlLog } from '../lib/log';
 import { capabilitiesProvider } from '../lib/capabilities';
 import { spacesUtilsProvider } from '../lib/spaces_utils';
 import type { RouteInitialization, SystemRouteDeps } from '../types';
-import { getMlNodeCount } from '../lib/node_utils';
+import { getLazyMlNodeCount, getMlNodeCount } from '../lib/node_utils';
 
 /**
  * System routes
@@ -187,10 +187,15 @@ export function systemRoutes(
 
           let isMlAutoscalingEnabled = false;
           try {
-            await client.asInternalUser.autoscaling.getAutoscalingPolicy({ name: 'ml' });
+            // kibana_system user does not have the manage_autoscaling cluster privilege.
+            // perform this check as a current user.
+            await client.asCurrentUser.autoscaling.getAutoscalingPolicy({ name: 'ml' });
             isMlAutoscalingEnabled = true;
           } catch (e) {
-            // If doesn't exist, then keep the false
+            // If ml autoscaling policy doesn't exist or the user does not have privileges to fetch it,
+            // check the number of lazy ml nodes to determine if autoscaling is enabled.
+            const lazyMlNodeCount = await getLazyMlNodeCount(client);
+            isMlAutoscalingEnabled = lazyMlNodeCount > 0;
           }
 
           return response.ok({